RNS Number:6617O
Xenova Group PLC
14 August 2003

Under Embargo - not to be released until 0700 14 August 2003


Xenova Group plc, 14 August 2003


Offer for KS Biomedix HoldingS Plc


Not for release, distribution or publication in or into the United States,
Canada, Australia or Japan


Summary announcement


Recommended Offer by Nomura on behalf of Xenova Group plc ("Xenova") for KS
Biomedix Holdings Plc ("KS Biomedix")


The Boards of Xenova and KS Biomedix today announce that they have agreed terms
for a recommended all share offer to be made by Nomura on behalf of Xenova to
acquire KS Biomedix.


Transaction Highlights



*  Creation of a stronger oncology business, combining product candidates
and development expertise in this important therapeutic area.



*  Focus development on commercially more attractive and later stage drug
candidates in order to extract the greatest value and near term benefits.



*  Significant opportunities for synergies and cost savings by
rationalising and consolidating the development functions, operational sites and
central support costs of the two groups and by selling off or closing non-core
operations.



*  Wider group of corporate partners including Celltech, Genentech,
Lilly, Millennium, Nycomed, Pfizer and QLT with opportunities to enter into
further licensing agreements.



*  Better positioned both for growth in the oncology market and for
participating in further consolidation opportunities.



*  Interim results for Xenova for six months to 30 June 2003 and
preliminary results for KS Biomedix for the year ended 31 May 2003 announced
today (see separate press releases).


Details of the Offer


The Offer is to be effected through a recommended all share offer being made by
Nomura, on Xenova's behalf, to acquire all of the KS Biomedix Shares.



*  Xenova will offer, for every KS Biomedix Share, 1.0714 New Xenova
Shares plus Deferred Consideration of new Xenova Shares to the value of 10
pence, which will be payable if TransMIDTM, KS Biomedix's most advanced clinical
drug candidate, is commercially sold in the EU or US markets by 14 August 2011.



*  The Offer values each KS Biomedix Share, on the basis of the Closing
Price of 12.25 pence per Xenova Share on 13 August 2003 and excluding the
Deferred Consideration, at approximately 13.12 pence and the KS Biomedix Issued
Share Capital at approximately #8.48 million.



*  The Deferred Consideration, if payable, would amount to additional
consideration of approximately #6.46 million being paid to KS Biomedix
Shareholders in the form of new Xenova Shares.



*  The Offer (excluding the Deferred Consideration) represents a discount
of 14 per cent. to the Closing Price of 15.25 pence per KS Biomedix Share on 30
July 2003, the business day immediately prior to the date of the commencement of
the Offer Period and a premium of 4.6 per cent. to the 30 trading day Closing
Price average of KS Biomedix Shares up to and including 30 July 2003.



*  Irrevocable undertakings to accept the Offer have been given
in respect of the aggregate beneficial holdings of the KS Biomedix Directors in
respect of 31,179,486 KS Biomedix Shares representing approximately 48.3 per
cent. of the KS Biomedix Issued Share Capital.



*  The KS Biomedix Directors, who have been so advised by Rothschild,
consider the terms of the Offer to be fair and reasonable, and unanimously
recommend KS Biomedix Shareholders to accept the Offer. In providing its advice
to the KS Biomedix Directors, Rothschild has taken into account the commercial
assessment of the KS Biomedix Directors.



Commenting on the Offer, David Oxlade, Chief Executive Officer of Xenova, said,
"Our objective is to build a profitable, oncology focused UK biotechnology
company with a sufficiently broad portfolio to manage risk for investors and
provide medium term returns to shareholders through successful drug development.
Our acquisition of KS Biomedix, which adds a product at the Phase III
development stage and two other clinical programmes to Xenova's existing
pipeline of nine drugs in clinical development, is another step along the road
to achieving this objective."


Dr. Steven Powell, Chief Executive Officer of KS Biomedix, commented, "We
believe that this transaction is in the best long-term interests of KS Biomedix
shareholders and recommend that they accept the offer."



THIS ABOVE SUMMARY SHOULD BE READ IN CONJUNCTION WITH THE FULL TEXT OF THE
FOLLOWING ANNOUNCEMENT ABOUT THE OFFER.


TERMS USED IN THIS SUMMARY SHALL HAVE THE MEANING GIVEN TO THEM IN APPENDIX 2 TO
THE FULL ANNOUNCEMENT.


A presentation for analysts will be held at the offices of Financial Dynamics,
Holborn Gate, 26 Southampton Buildings, London WC2A 1PB, at 9.15am today, 14
August 2003.  Coffee will be available from 9am.  Please call Mo Noonan for
further details on 020 7269 7116.



Enquiries:


Xenova                      David Oxlade          Tel: 01753 706 600
                            Daniel Abrams

Nomura International        Charles Spicer        Tel:  020 7521 2000
                            David Rasouly

Financial Dynamics          David Yates           Tel: 020 7831 3113
                            Ben Atwell

KS Biomedix                 Steven Powell         Tel: 01483 307 500
                            Ian Miscampbell

Rothschild                  Dominic Hollamby      Tel:  020 7280 5000


The Xenova Directors and the KS Biomedix Directors are the persons responsible
for the information contained in this announcement.  To the best of the
knowledge and belief of such directors (who have taken all reasonable care to
ensure that such is the case) the information contained in this announcement is
in accordance with the facts and does not omit anything likely to affect the
import of such information.



Nomura is acting for Xenova and no one else in connection with the Offer and
will not be responsible to any person other than Xenova for providing the
protections afforded to clients of Nomura, or for providing advice in relation
to the Offer or the New Xenova Shares.



Rothschild is acting for KS Biomedix and no one else in connection with the
Offer and will not be responsible to any person other than KS Biomedix for
providing the protections afforded to clients of Rothschild, or for providing
advice in relation to the Offer.



This announcement does not constitute an offer or an invitation to purchase any
securities.



This announcement does not constitute an offer of securities for sale in the
United States and the New Xenova Shares have not been, and will not be,
registered under the United States Securities Act of 1933, as amended, nor under
any laws of any state of the United States, and the relevant clearances have not
been and will not be obtained from the relevant authorities in Canada, Australia
or Japan.  Accordingly, unless an exemption under any applicable laws is
available, the New Xenova Shares may not be offered, sold, resold, delivered or
transferred directly or indirectly, in or into the United States, Canada,
Australia or Japan or any other country outside the United Kingdom where such
distribution may otherwise lead to a breach of law or other regulatory
requirement, or to or for the benefit of US Persons.



The Offer referred to in this announcement is not being made, directly or
indirectly, in or into, or by use of the mails of or by any means or
instrumentality (including, without limitation, facsimile transmission, telex,
telephone or internet) of interstate or foreign commerce of, or any facilities
of a securities exchange of, the United States, nor is it being made, directly
or indirectly, to or for the benefit of US Persons,nor is it being made,
directly or indirectly, in or into Canada, Australia or Japan unless an
exemption under any applicable laws is available. This announcement is not
being, and it must not be, mailed or otherwise forwarded, distributed or sent
in, or into the United States, Canada, Australia or Japan and doing so may
render invalid any purported acceptance of the Offer.



This announcement contains certain statements that are or may be forward-looking
with respect to the financial conditions, results of operations and business
achievements/performance of Xenova, KS Biomedix and/or the Enlarged Group. By
their nature, forward-looking statements involve risk and uncertainty because
they relate to events and depend on circumstances that will occur in the future.



The attention of member firms of NASDAQ is drawn to certain UK dealing
disclosure requirements. The announcement on 31 July 2003 by KS Biomedix of the
possibility of an offer commenced an offer period in accordance with the City
Code, which is published and administered by the Panel. KS Biomedix has equity
securities traded on the London Stock Exchange. Xenova has equity securities
traded on NASDAQ and the London Stock Exchange.



The disclosure requirements are set out in more detail in Rule 8 of the City
Code. In particular, Rule 8.3 of the City Code requires public disclosure of
dealings during the offer period by persons who own or control, or who would as
a result of any transaction own or control, 1 per cent. or more of any class of
relevant securities of KS Biomedix or Xenova. Relevant securities include KS
Biomedix Shares, Xenova Shares, instruments convertible into such shares and
options and derivatives referenced to any such shares. In the case of the Offer
for KS Biomedix, this requirement will apply until the first closing date, 4
September 2003, or, if this is later, the date when the Offer becomes or is
declared unconditional as to acceptances or lapses.



Disclosure should be made on an appropriate form no later than 12 noon London
time on the business day following the date of the dealing transaction. These
disclosures should be sent to one of the Regulatory Information Services
approved for the purposes of the Listing Rules of the UK Listing Authority.The
Panel requests that member firms advise those of their clients who wish to deal
in the relevant securities, whether in the US or in the UK, that they may be
affected by these requirements. If there is any doubt as to their application,
the Panel should be consulted (telephone number: +44 (0)20 7638 0129, fax
number: +44 (0)20 7638 1554).




Offer for KS Biomedix HoldingS Plc


Not for release, distribution or publication in or into the United States,
Canada, Australia or Japan



Full text of the announcement


Recommended Offer by Nomura on behalf of Xenova Group plc ("Xenova") for KS
Biomedix Holdings Plc ("KS Biomedix")


1.                Introduction



The Boards of Xenova and KS Biomedix today announce that they have agreed terms
for a recommended all share offer to be made by Nomura on behalf of Xenova to
acquire KS Biomedix.



Xenova will offer, for every KS Biomedix Share, 1.0714 New Xenova Shares plus
Deferred Consideration of new Xenova Shares to the value of 10 pence, which will
be payable if TransMIDTM, KS Biomedix's most advanced clinical programme, is
commercially sold in the EU or US markets by 14 August 2011.  The Offer values
each KS Biomedix Share, on the basis of the Closing Price of 12.25 pence per
Xenova Share on 13 August 2003 and excluding the Deferred Consideration, at
approximately 13.12 pence and the KS Biomedix Issued Share Capital at
approximately #8.48 million.  In addition, in certain circumstances KS Biomedix
Shareholders who sell their KS Biomedix Shares pursuant to the Offer will be
entitled to receive the Deferred Consideration which, if payable, would amount
to additional consideration of approximately #6.46 million being paid to KS
Biomedix Shareholders in the form of new Xenova Shares.


2.                    Recommendation and undertakings



The KS Biomedix Directors, who have been so advised by their financial advisers,
Rothschild, consider the terms of the Offer to be fair and reasonable.  In
providing its advice to the KS Biomedix Directors, Rothschild has taken into
account the commercial assessment of the KS Biomedix Directors.



Accordingly, the KS Biomedix Directors will be unanimously recommending KS
Biomedix Shareholders to accept the Offer.  Irrevocable undertakings have been
given in respect of the aggregate beneficial holdings of the KS Biomedix
Directors in respect of 31,179,486 KS Biomedix Shares, representing
approximately 48.3 per cent. of KS Biomedix Issued Share Capital. The
irrevocable undertakings require acceptance of the Offer (unless the Offer is
withdrawn or lapses) even in the event of a higher competing offer from a third
party.





Given its size, the Offer is conditional, amongst other things, upon the
approval of Xenova Shareholders. The Xenova Directors consider the Acquisition
to be in the best interests of the Xenova Shareholders as a whole. Accordingly,
the Xenova Directors will be unanimously recommending Xenova Shareholders to
vote in favour of the resolutions necessary to effect the Offer as they intend
to do in respect of their own aggregate beneficial holdings of 633,044 Xenova
Shares representing approximately 0.36 per cent. of Xenova's existing issued
share capital.


3.                    The Offer



On behalf of Xenova, Nomura has offered to acquire all of the KS Biomedix Shares
on the following basis:


for every KS Biomedix Share           1.0714 New Xenova Shares + Deferred Consideration


and so in proportion for any other number of KS Biomedix Shares held.



The Deferred Consideration entitles each KS Biomedix Shareholder who sells its
KS Biomedix Shares pursuant to the Offer to receive, in respect of each KS
Biomedix Share, new Xenova Shares to the value of 10 pence in the event that
TransMIDTM (KS Biomedix's most advanced clinical programme) is commercially sold
in either of the EU or US markets by 14 August 2011. The Xenova Directors
estimate that the earliest date for commercial sale of TransMIDTM will be mid
2007. The detailed terms and conditions of the Deferred Consideration are set
out in paragraph 12 below.



Full acceptance of the Offer (without taking account of the exercise of any
options under the KS Biomedix Share Option Schemes or the Deferred
Consideration) would result in the issue of approximately 69.2 million New
Xenova Shares to KS Biomedix Shareholders, representing 28.4 per cent. of the
enlarged issued ordinary share capital of Xenova.



The Offer extends to all KS Biomedix Shares. The Offer will initially be open
for acceptance until 3.00 p.m. on 4 September 2003, but may be extended in
accordance with the Code.



The KS Biomedix Shares will be acquired by Xenova fully paid and free from all
liens, charges, encumbrances, rights of pre-emption and any other third party
rights or interests of any nature whatsoever and together with all rights
attaching thereto, including the right to receive all dividends and other
distributions (if any) declared, made or paid after 14 August 2003. The KS
Biomedix Board has not declared or recommended any dividends since
incorporation.



The New Xenova Shares to be issued pursuant to the Offer will be issued credited
as fully paid and will rank pari passu in all respects with the existing Xenova
Shares.



4.                    Reasons for and benefits of the Offer



The Xenova Directors and Proposed Directors believe that the Enlarged Group will
deliver greater shareholder value than if the two companies remain apart. The
combined product pipeline will increase the chances of successfully bringing new
products to market and reduce the overall risk profile of the portfolio,
although further funding will be required by the Enlarged Group to develop
TransMIDTM, as discussed further in paragraph 7 below entitled "Prospects of the
Enlarged Group". The Acquisition will also create a wider shareholder base that
should stimulate greater liquidity and therefore promote a broader level of
interest in the equity of the Enlarged Group.



In particular the Xenova Directors and Proposed Directors consider that the
Enlarged Group will benefit from the following key factors:



  * The combination of the Xenova Group and the KS Biomedix Group will create
    a business with a focus on oncology, combining the product candidates and
    development expertise of both groups in this therapeutic area. The Enlarged
    Group will have a total of 8 oncology product candidates under clinical
    development, comprising 1 at the Phase III development stage, 2 in Phase II
    and 5 in Phase I, and a number of further oncology programmes in preclinical
    development. The modes of action of these product candidates provide a range
    of therapeutic approaches including tumour specific biological agents, DNA
    targeting agents and drug resistance modulation. The Xenova Directors and
    Proposed Directors consider that oncology presents a highly attractive area
    of therapeutic focus due to the high level of unmet need in a large number
    of different indications, and the rapid adoption of treatments due to the
    poor outcomes with existing treatments.



  * In addition to oncology, the Enlarged Group will also have a further 4
    drug candidates at the clinical stage of development in the areas of
    addiction and immunology giving it a broad pipeline of drug candidates.
    Xenova will focus its development efforts on the commercially more
    attractive and later stage drug candidates in the enlarged drug candidate
    portfolio in order to extract the greatest value and near term benefits.



  * The Enlarged Group will have a wider group of corporate partners including
    Celltech, Genentech, Lilly, Millennium, Nycomed, Pfizer and QLT. The Xenova
    management has demonstrated a strong track record of entering into
    attractive licensing agreements for individual territories over the last 2
    years while retaining valuable territorial rights within the business for
    outlicensing at a later stage. Through licensing arrangements, four of
    Xenova's clinical programmes, as well as some of its earlier stage
    programmes, benefit from external funding. There are also expected to be
    opportunities for Xenova management to enter into further attractive
    licensing agreements with the product candidates in the Enlarged Group.



  * There will be a significant opportunity for synergies and cost savings in
    the Enlarged Group by rationalising and consolidating the development
    functions, operational sites and central support costs of the two groups and
    by selling off or closing non-core operations, which may also raise
    additional funds to invest in key drug candidate development programmes. In
    particular, following the Acquisition, there will be manufacturing
    operations in both Edmonton, Canada and Cambridge, UK which may be
    rationalised. One strategic option under review is the disposal of one of
    the manufacturing sites whilst retaining long-term manufacturing supply
    contracts with the acquirer of the site in order to maintain the supply of
    clinical material for the Enlarged Group's own clinical trials. Non-core
    operations include KS Biomedix's joint venture, Discerna. Following
    completion of the planned rationalisation of the operations of the two
    companies, and including the changes Xenova is currently implementing
    following the announcement on 12 May 2003 of the termination of Phase III
    trials of tariquidar, the Xenova Directors and Proposed Directors expect the
    total number of employees on a combined basis to fall from approximately 185
    to approximately 105; and estimate that annualised cost-savings of
    approximately #10 million will have been achieved across both businesses,
    based on reductions in headcount, facilities and research and development
    costs. The one-off cost of achieving these cost savings is expected to be
    approximately #2.7 million.



  * The Xenova Directors and Proposed Directors also believe that the enlarged
    pipeline with its strong focus on oncology will put the Enlarged Group in a
    better position to take part in further consolidation opportunities in the
    sector which, if such opportunities should arise and are in the best
    interests of the Enlarged Group, the Xenova Directors and Proposed Directors
    will pursue.



The Listing Particulars set out certain Risk Factors relating to the Enlarged
Group.



5.        Information on Xenova



Xenova is an emerging bio-pharmaceutical company which was founded in the UK and
commenced operations in 1987. The Company merged with Cantab in April 2001, and
is currently focused on cancer therapy and immunotherapy. Xenova currently has
nine products in clinical development, including new chemical entities for the
treatment of cancer, and vaccines for the treatment of infectious disease,
addiction and cancer. Xenova has in its ownership, or licensed to it, a total of
more than 35 families of patent application and/or granted patents.



Based in Slough and Cambridge in the UK, Xenova currently employs approximately
78 people at its two locations, of whom approximately 50 are directly involved
in drug research and development. The Xenova Group's head office, housing its
small molecule research and development capability, is located in Slough while
the Xenova Group's immunotherapy activities are carried out at its Cambridge
site. The Company also has a biologicals manufacturing plant located at the
Cambridge site, which is used for the production of clinical grade materials for
its own clinical trials and for contract manufacturing on behalf of third party
clients.



Xenova seeks to commercialise its development products through partnering with
major pharmaceutical companies. It considers the optimal timing for partnering
on a project by project basis following an assessment of the scientific and
commercial risks and returns for each individual project. However, in general, a
licensing partner will be sought to assist with the Phase III trials and to take
on the marketing and distribution of the product.



The unaudited interim results of Xenova for the six months to 30 June 2003 were
announced today. These show that for the six months Xenova incurred a loss on
ordinary activities before taxation and R&D tax credits of #8.1 million (2002:
#5.5 million) and as at that date had net assets of #19.4 million (2002: #25.2
million) and cash, short-term deposits and investments of #10.1 million (2002:
#15.1 million).



On 12 May 2003, it was announced that the Phase III trials of tariquidar,
Xenova's lead product, would be stopped following a recommendation from the
DSMC, an independent committee, which had completed the un-blinded interim
review of data for the two ongoing trials. This recommendation was immediately
implemented and Phase III trials were terminated. Following the termination of
these Phase III trials, Xenova implemented an R&D reorganisation, which included
both headcount reduction and programme prioritisation. As a result, Xenova is
focussing on its key later stage clinical development programmes. These changes,
mainly affecting the research functions in Cambridge and Slough, will result in
a headcount of 66 (down from 107 at the time of the announcement by the Company
on 12 May 2003 of the termination of Phase III trials of tariquidar) by the end
of September 2003.



The Xenova Directors expect that losses and cash outflows will continue for a
number of years. However, the Xenova Directors believe that the Acquisition will
place the Company in a stronger position to continue the development of the
Company's business.



The Xenova Directors believe there are a number of reasons for and benefits of
acquiring KS Biomedix and these are set out under the heading "Reasons for and
benefits of the Offer" in section 4 of this announcement. One of the benefits of
the Acquisition is the opportunity to save costs and to use the funds and assets
of both companies across a reduced cost base. Xenova Shareholders should be
aware that if the Acquisition does not proceed the Xenova Group would not have
sufficient working capital for at least the next 12 months from the date of this
announcement, to support its planned level of activities. However, there is no
immediate requirement for funds and the Xenova Directors believe that the Xenova
Group has sufficient working capital for a substantial part of the next 12
months based on its planned level of activities.



If the Acquisition does not proceed, the Xenova Group would seek additional
finance which might include some form of equity financing from institutional or
other investors. Should the Xenova Group be unable to secure additional finance,
Xenova would seek to take steps to reduce its activities in order to enable
Xenova, on a standalone basis, to remain a going concern for at least the next
12 months from the date of publication of this document. Such steps would
include a reduction in overheads and development expenditure on its drug
candidates which may delay, reduce or eliminate the development of product
candidates which are not externally funded by partners. In addition, Xenova may
also be forced to license the rights to some of its drug candidates and
technologies at an earlier stage than would otherwise be intended which would be
likely to be on less favourable terms.



6.        Information on KS Biomedix



KS Biomedix is a drug research and development group focused on the development
of products for the treatment of cancer, particularly clinical indications where
survival prognosis is poor and there are few, if any, approved products. KS
Biomedix's product portfolio has three products in its clinical pipeline to
treat eight different indications, including four specific brain cancer patient
groups. Underpinning its drug development, KS Biomedix has patented technology
based on the principle of tumour targeting.



Headquartered in Guildford in the UK, KS Biomedix currently employs 76 people,
of whom approximately 63 are directly involved in drug research and development.
The company has facilities or offices in Guildford (UK), Farnham (UK), Edmonton
(Canada) and Philadelphia (USA).



Guildford houses the management and head office functions including project
management and regulatory and clinical development. Farnham houses research and
product development capabilities for the KS Biomedix Group. Edmonton houses KS
Biomedix's manufacturing facility, which is capable of manufacturing biologicals
and is used to produce its own products for clinical trials as well as
potentially generating revenues from third parties through contract
manufacturing. A small office in Philadelphia is responsible for the US clinical
trials of TransMIDTM, its lead product, as well as liasing with the FDA.



KS Biomedix has partnered TransMIDTM to Sosei (Japan), Nycomed (EU), Ranbaxy
(India) and Medison (Israel) but has retained the rights to TransMIDTM in the
Americas. KS Biomedix's other products are not yet licensed-out.



The preliminary results of KS Biomedix were announced today. The audited results
show that KS Biomedix incurred a loss on ordinary activities before taxation and
R&D tax credits of #33.9 million (2002: #15.3 million) and as at that date had
net assets of #16.1 million (2002: #49.2 million) and cash and liquid
investments of #7.4 million (2002: #17.6 million). The accounts include an
additional write-off of goodwill of #20.9 million following the completion of an
impairment review and in light of the terms of the Offer.



Since 31 May 2003, KS Biomedix has continued to incur losses, in line with the
KS Biomedix Directors' expectations, as it continues to incur expenditure to
progress the development of its drug candidates and early stage programmes.



7.        Prospects of the Enlarged Group



The Enlarged Group will have a broad pipeline of products with a total of 12
products in clinical stage development with a strong focus on oncology,
including 3 later stage oncology products in Phase II and III development.



The most advanced product in the enlarged pipeline will be TransMIDTM, a
treatment for high-grade glioma, which has commenced Phase III development and
will shortly be ready to enter Phase III clinical trials. The KS Biomedix
Directors estimate the cost of the currently planned single Phase III pivotal
study, the protocol of which is in the process of being approved by the FDA, to
be in the region of #17 million. However, following the Acquisition Xenova
intends to pursue a longer but lower risk option, undertaking instead two
smaller Phase III studies, each costing approximately #9 million. Subject to FDA
and other regulatory approvals, and the raising of funds which will be required
to finance the Phase III trials, the first of these trials would commence
immediately. This would enable the Enlarged Group, if necessary, to select an
appropriate partner for the North American market to fund the second Phase III
trial if the review of clinical data of the first study shows positive results.



The second most advanced product is tariquidar, the revised clinical development
plans for which are currently being jointly developed by Xenova and QLT, its
North American development partner, following the unblinding of the data from
the Phase III studies which resulted in the termination of these trials.



The Enlarged Group intends to seek additional funds through equity financing
from institutional and other investors once the Offer becomes unconditional in
all respects in order to provide sufficient finance to carry out the initial
Phase III trial for TransMIDTM and to continue to fund the development of other
product candidates in the Enlarged Group's product portfolio.



The Enlarged Group provides significant opportunities for reducing the overall
costs by rationalisation of the operations of the two businesses, removing
duplicated central overhead costs, reducing the number of operational sites and
selling off or closing non-core activities. It is anticipated that reductions in
headcount, facilities and research and development costs will yield annualised
cost savings of up to #10 million across both businesses. The one-off costs of
achieving these cost savings is expected to be approximately #2.7 million.



The Xenova Directors and the Proposed Directors believe the Enlarged Group will
continue to make losses over the course of the current year as it continues to
develop its drug candidates, and it incurs the one-off cost of carrying out the
rationalisation. The rationalisation is expected to be largely complete by the
end of 2003 and as a  result the operating losses for 2004 are expected to
benefit from this. The Enlarged Group will focus its development efforts on the
commercially more attractive and predominantly later stage drug candidates and
will benefit from the fact that five of its clinical programmes will benefit
from external funding.



Xenova has a plan for implementing the integration and rationalisation of KS
Biomedix and has shown it has the relevant experience to do this following the
merger with Cantab in 2001 which required rationalisation and integration of
that business.



The Xenova Directors and Proposed Directors believe that the expanded oncology
focused product pipeline and reduced and refocused cost base of the business
will provide a better opportunity for bringing new products to market within the
resources of the Enlarged Group and help to improve the prospects of the Xenova
Group.



8.        Enlarged Group's products



The Enlarged Group will focus on oncology, with a secondary focus on addiction.
The Enlarged Group's drug candidates and early development programmes are
summarised in the table below:


Drug Candidates/Programmes Therapeutic area         Stage of Development     Partner
Clinical programmes

TransMIDTM (KSB311)*       Glioma                   Phase III                Sosei, Nycomed,
                                                                             Medison, Ranbaxy

Tariquidar (XR9576)*       Cancer                   Phase II                 QLT (North
                                                                             America only)

TA-HPV / TA-CIN            Cervical cancer          Phase II                 -

TA-CD*                     Cocaine addiction        Phase II                 NIDA1

KSB303*                    Cancer                   Phase I                  -

HumaRAD                    Cancer                   Phase I                  -

XR11576*                   Solid tumours            Phase I                  Millennium (North
                                                                             America only)

XR5944*                    Solid tumours            Phase I                  As XR11576

DISC-PRO                   Genital and oro-labial   Phase I                  -
                           herpes prophylaxis

TA-NIC*                    Nicotine addiction       Phase I                  -

DISC-GMCSF                 Cancer                   Phase I                  -

DISC-VET                   Bovine Herpes Virus      Phase I equivalent       Pfizer

Early development programmes

Triomics                   Solid tumours            Preclinical              -

XR11612                    Solid tumours            Preclinical              As XR11576

OX-40                      Autoimmune Disorders     Preclinical              Celltech, Genentech

OX-40L                     Infectious diseases,     Preclinical              -
                           anti-cancer

PAI-1                      Cardiovascular           Preclinical              Lilly

PAI-1                      Cancer                   Preclinical              Lilly (option)2

MRP                        Cancer and asthma        Preclinical              -

M3                         Inflammatory disease and Preclinical              -
                           cancer

VP22 (Phogen joint         Intra-cellular delivery  Preclinical              Genencor
venture)                   system

HIF-1 alpha                Cancer                   Preclinical              -

MEN-B                      Meningitis               Preclinical              -

KSB 304                    Ulcerative colitis       Preclinical              -

KSB 113                    Cancer                   Preclinical              -

Ribosome display           Cancer targets           Preclinical              Babraham
(Discerna)


1 NIDA provides funding to independent investigators to conduct certain trials
of TA-CD, but has no rights for its commercialisation, nor is funding required
to be repaid by Xenova.

2 Lilly has an option to acquire development and commercialisation rights
relating to PAI-1 inhibitors in the cancer field.


Drug candidates indicated with an asterisk (*) will be prioritised for internal
development following the Acquisition.



Unless otherwise indicated, commercial rights to the programmes shown in the
above schedule are held

by Xenova or KS Biomedix.



Product Strategy

Following the Acquisition, the clinical portfolio will be prioritised. The
Directors believe that the increased focus on the seven key clinical development
programmes (see drug candidates indicated with an asterisk (*) in table above)
will provide a greater return to shareholders. Of these seven, five (TransMIDTM,
tariquidar, TA-CD, XR11576 and XR5944) benefit from external funding.



The Enlarged Group will de-prioritise the majority of the early development
programmes, except where externally funded, as is the case for the Genentech
collaboration on OX-40. The Directors intend to pursue licensing opportunities
for those programmes which have been de-prioritised.



9.        Directors, management and employees



Following the Offer becoming or being declared unconditional in all respects,
John Rennocks and Dr. Michael Young, non-executive directors of KS Biomedix,
will join the board of Xenova as non-executive directors.



In addition, on the Offer becoming or being declared unconditional in all
respects, the KS Biomedix executive directors, Dr. Steven Powell and Ian
Miscampbell, will resign from the KS Biomedix Board pursuant to separate
compromise agreements. The remaining non-executive directors of KS Biomedix
(other than Mr. Rennocks and Dr. Young) will also resign from the KS Biomedix
Board on the Offer becoming or being declared unconditional in all respects.



In respect of Dr Fahar Merchant, Xenova has entered into a consultancy agreement
(conditional on the Offer becoming or being declared unconditional in all
respects) with, amongst others, Dr. Fahar Merchant, commencing on 1 October 2003
for a period of up to two years pursuant to which he will provide to Xenova
certain consultancy services for a fee of #50,000 per annum. The appointment can
be terminated on 3 months' notice by either party provided that Dr Merchant will
be entitled to receive a minimum sum of #50,000 in respect of the appointment.



It is also intended that following completion of the Acquisition there will be a
further reconstruction of the non-executive directors of the Enlarged Group, but
that this reconstruction will not affect the appointment or position of the
Proposed Directors as referred to above.



The Xenova Board and the Proposed Directors have confirmed that the existing
employment rights, including the pension rights, of all employees of the KS
Biomedix Group will be safeguarded following completion of the Acquisition.



10.     KS Biomedix Share Option Schemes



All options under the KS Biomedix Share Option Schemes will become exercisable
once the Offer becomes or is declared unconditional in all respects.



Optionholders who decide to exercise their options will be able to accept the
Offer (while it remains open for acceptance) in respect of the KS Biomedix
Shares they receive on exercise. However, it may not be in the interests of all
KS Biomedix optionholders to exercise their options, depending on the relevant
option exercise price and the value of the Xenova Shares. Xenova will write to
KS Biomedix optionholders in more detail on this subject in due course.



11.     Settlement, listing, dealing and compulsory acquisition



Application has been made for the New Xenova Shares to be admitted to the
Official List and to be admitted to trading on the London Stock Exchange's
market for listed securities. It is expected that admission to listing of those
securities will become effective and dealings, for normal settlement, on the
London Stock Exchange will commence on the first business day following the day
on which the Offer becomes or is declared unconditional in all respects (save
only for admission of the New Xenova Shares to the Official List becoming
effective).



Fractions of New Xenova Shares will not be allotted or issued to persons
accepting the Offer and such entitlements to New Xenova Shares under the Offer
will be rounded down to the nearest whole number of New Xenova Shares.
Fractional entitlements to New Xenova Shares will be aggregated and sold in the
market and the proceeds will be retained for the benefit of the Enlarged Group.



After the Offer becomes or is declared unconditional in all respects, Xenova
intends to procure the making of an application by KS Biomedix for the removal
of the KS Biomedix Shares from the Official List. It is anticipated that such
delisting will take effect no earlier than 20 business days after the Offer
becomes unconditional in all respects.



If Xenova receives acceptances under the Offer in respect of, and/or otherwise
acquires, 90 per cent. or more of the KS Biomedix Shares to which the Offer
relates, Xenova will exercise its rights pursuant to the provisions of sections
428 to 430F of the Act to acquire compulsorily the remaining KS Biomedix Shares
to which the Offer relates.



Subject to the Offer becoming or being declared unconditional in all respects,
settlement of the consideration to which any KS Biomedix Shareholder is entitled
under the Offer (but for this purpose excluding the Deferred Consideration) will
be effected (i) in the case of acceptances of the Offer received, complete in
all respects, by the date on which the Offer becomes or is declared
unconditional in all respects, within 14 days of such date, or (ii) in the case
of acceptances of the Offer received, complete in all respects, after the date
on which the Offer becomes or is declared unconditional in all respects but
while it remains open for acceptances, within 14 days of such receipt.



Where an acceptance relates to KS Biomedix Shares held in CREST (that is, in
uncertificated form) the New Xenova Shares to which the accepting KS Biomedix
Shareholder is entitled will be issued to such shareholder in uncertificated
form within the CREST system (unless Xenova decides otherwise).



Where an acceptance relates to KS Biomedix Shares in certificated form, the New
Xenova Shares to which the accepting KS Biomedix Shareholder is entitled will be
issued in certificated form. Definitive certificates for the New Xenova Shares
will be despatched by first-class post (or by such other method as may be
approved by the Panel).



In relation to New Xenova Shares issued in certificated form, temporary
documents of title will not be issued. Pending the despatch by post of
definitive certificates for such New Xenova Shares in accordance with the terms
of the Offer, transfers will be certified against the register.



Further details on settlement, listing and dealing will be included in the
formal documents to be sent to KS Biomedix Shareholders and Xenova Shareholders
in due course.



12.     Deferred Consideration



The Deferred Consideration will become payable by Xenova if by 14 August 2011
(being the date eight years from publication of this announcement) any person
(whether or not a member of the Xenova Group or any of its partners or
licensees):

  * has obtained regulatory approval or marketing authorisation for marketing
    TransMIDTM in the US, EU or any three EU countries, and
  * has Commercially Sold TransMIDTM.



Xenova will make an announcement as soon as reasonably practicable after, in
each case, it becomes aware of the first occurrence of the relevant event.



If the Deferred Consideration becomes payable, each KS Biomedix Shareholder
shall receive, for each KS Biomedix Share sold pursuant to the Offer, new Xenova
Shares to the value of 10 pence based on the average Closing Price of a Xenova
Share during the Valuation Period.



As soon as reasonably practicable after the announcement that TransMIDTM has
been Commercially Sold, Xenova will issue the appropriate number of Xenova
Shares to each KS Biomedix Shareholder for each KS Biomedix Share sold pursuant
to the Offer. Prior to the issue of these new Xenova Shares, Xenova will comply
with any necessary procedures to ensure that these new Xenova Shares will be
listed, including making an application to the UKLA for such shares to be
admitted to the Official List. Application will also be made to the London Stock
Exchange for the shares to be admitted to trading on the London Stock Exchange's
market for listed securities.



The new Xenova Shares issued as aforesaid will be issued credited as fully paid
up and free from all liens, charges, encumbrances, rights of pre-emption and any
other third party rights or interests of any nature whatsoever and will rank
pari passu in all respects with the Xenova Shares existing at that time.



On payment of the Deferred Consideration, if any KS Biomedix Shareholder would
be entitled to a fractional entitlement of new Xenova Shares, then if the value
of such entitlement is in excess of #2.50 such entitlement shall be satisfied in
cash and paid to such KS Biomedix Shareholder. Fractional entitlements below
#2.50 will be aggregated and sold in the market for Xenova's benefit.



If Xenova is acquired by a third party which is listed, the Xenova Board shall
use reasonable endeavours to ensure that in respect of each KS Biomedix Share
sold pursuant to the Offer, the relevant KS Biomedix Shareholders will receive,
if the Deferred Consideration becomes payable, shares, credited as fully paid,
in the acquirer, to the value of 10 pence based on the average closing price of
a share in the acquirer during the Valuation Period. If Xenova is acquired by a
third party which is not listed or the Xenova Board has been unable to ensure
such arrangements are implemented, Xenova will, if the Deferred Consideration
becomes payable, issue unsecured loan stock to KS Biomedix Shareholders on
reasonable commercial terms, repayable six months after issue to a value of 10
pence for each KS Biomedix Share sold pursuant to the Offer.



Entitlement to receive the Deferred Consideration shall not be transferable
under any circumstances, other than by operation of law on the death of a person
entitled to the Deferred Consideration. No certificate or other document of
title shall be issued by the Company to KS Biomedix Shareholders in respect of
their entitlements to the Deferred Consideration.



The Xenova Directors and the Proposed Directors of the Enlarged Group believe
that TransMIDTM offers significant prospects for profitable development and will
endeavour to achieve the launch of TransMIDTM as soon as is reasonably
practicable. However, KS Biomedix Shareholders should be aware that the decision
to progress towards and implement the launch of TransMIDTM will be a decision
for the Board of the Enlarged Group, to be taken in the best interests of the
Enlarged Group as a whole. Accordingly, it cannot be guaranteed that the
Deferred Consideration will become payable in the future.



In the event that the Deferred Consideration has not become payable by 14 August
2011, the Deferred Consideration will not become payable under any
circumstances.



13.     Overseas Shareholders



The availability of the Offer to persons not resident in the UK may be affected
by the laws of the relevant jurisdictions.  In particular, the Offer will not be
made, directly or indirectly, in or into the United States, Canada, Australia or
Japan to or for the benefit of US Persons unless an exemption under any
applicable laws is available.  KS Biomedix Shareholders who are not resident in
the UK should inform themselves about and observe any applicable requirements.



Further details in relation to overseas shareholders are contained in the Offer
Document.



14.     Expected Timetable and Documents



The formal Offer Document, setting out full details of the Offer, together with
Listing Particulars and a Form of Acceptance, will be posted to KS Biomedix
Shareholders today.  The Offer Document and the Listing Particulars will also be
despatched to KS Biomedix optionholders for information only.  A circular
containing a notice convening an Extraordinary General Meeting of Xenova
Shareholders to approve, inter alia, the Offer, together with the Listing
Particulars, will also be despatched today to Xenova Shareholders and to Xenova
optionholders for information only.



The Xenova EGM will be held at 10 am on 1 September 2003 and the first closing
of the Offer will be 3pm on 4 September 2003.



Copies of the Circular, Listing Particulars and Form of Proxy will shortly be
available for inspection at the UK Listing Authority's Document Viewing
Facility, which is situated at 25, The North Colonnade, Canary Wharf, London E14
5HS. Telephone no. +44 (0)20 7676 1000.



15.     General



As at 13 August 2003 (being the latest practicable date prior to the making of
this announcement), John Rennocks was interested in 79,437 KS Biomedix Shares.
Save as set out in this paragraph, neither Xenova, nor any directors of Xenova,
nor as far as Xenova is aware any party acting in concert with Xenova, owns or
controls any KS Biomedix Shares or holds options to purchase any KS Biomedix
Shares or has entered into any derivative transactions referenced to KS Biomedix
Shares.



Xenova has received irrevocable undertakings from all KS Biomedix Directors who
hold KS Biomedix Shares to accept the Offer in respect of a total of 31,179,486
KS Biomedix Shares, representing in aggregate approximately 48.3 per cent. of
the KS Biomedix Issued Share Capital.



In addition, each of Dr Kim Tan and Dr Fahar Merchant have agreed with Xenova
not to dispose of any of the New Xenova Shares to be issued to them in
connection with the Offer for a period of six months after the date on which the
New Xenova Shares are issued. Their New Xenova Shares will represent 13.4 per
cent. of the enlarged issued share capital of Xenova assuming full acceptance of
the Offer. These restrictions will not apply, in each case, to the acceptance of
a takeover offer for Xenova, to the giving of an irrevocable undertaking to a
potential offeror for Xenova, to the sale of shares to a person who has made or
announced a firm intention to make a takeover offer or is the subject of a Rule
2.4 announcement under the Code as offeror in connection with Xenova, with
Xenova's prior written consent and in certain other limited circumstances and,
in the case of Dr Merchant, where the total consideration received by him does
not exceed #300,000.



Further, Dr. Tan and Dr. Merchant have agreed that they shall not (except in
certain limited circumstances) dispose of any of their New Xenova Shares for a
further period of six months (commencing on expiry of the initial six-month
period) other than through Xenova's broker.



Enquiries:


Xenova                      David Oxlade          Tel: 01753 706 600
                            Daniel Abrams

Nomura International        Charles Spicer        Tel:  020 7521 2000
                            David Rasouly

Financial Dynamics          David Yates           Tel: 020 7831 3113
                            Ben Atwell

KS Biomedix                 Steven Powell         Tel: 01483 307 500
                            Ian Miscampbell

Rothschild                  Dominic Hollamby      Tel:  020 7280 5000



The Xenova Directors and the KS Biomedix Directors are the persons responsible
for the information contained in this announcement.  To the best of the
knowledge and belief of such directors (who have taken all reasonable care to
ensure that such is the case) the information contained in this announcement is
in accordance with the facts and does not omit anything likely to affect the
import of such information.



Nomura is acting for Xenova and no one else in connection with the Offer and
will not be responsible to any person other than Xenova for providing the
protections afforded to clients of Nomura, or for providing advice in relation
to the Offer or the New Xenova Shares.



Rothschild is acting for KS Biomedix and no one else in connection with the
Offer and will not be responsible to any person other than KS Biomedix for
providing the protections afforded to clients of Rothschild, or for providing
advice in relation to the Offer.



This announcement does not constitute an offer or an invitation to purchase any
securities.



This announcement does not constitute an offer of securities for sale in the
United States and the New Xenova Shares have not been, and will not be,
registered under the United States Securities Act of 1933, as amended, nor under
any laws of any state of the United States, and the relevant clearances have not
been and will not be obtained from the relevant authorities in Canada, Australia
or Japan.  Accordingly, unless an exemption under any applicable laws is
available, the New Xenova Shares may not be offered, sold, resold, delivered or
transferred directly or indirectly, in or into the United States, Canada,
Australia or Japan or any other country outside the United Kingdom where such
distribution may otherwise lead to a breach of law or other regulatory
requirement, or to or for the benefit of US Persons.



The Offer referred to in this announcement is not being made, directly or
indirectly, in or into, or by use of the mails of or by any means of
instrumentality (including, without limitation, facsimile transmission, telex,
telephone or internet) or interstate or foreign commerce of, or any facilities
of a securities exchange of, the United States, nor is it being made, directly
or indirectly, to or for the benefit of US Persons, nor is it being made,
directly or indirectly, in or into Canada, Australia or Japan unless an
exemption under any applicable laws is available. This announcementis not being,
and it must not be, mailed or otherwise forwarded, distributed or sent in, or
into the United States, Canada, Australia or Japan and doing so may render
invalid any purported acceptance of the Offer.



This announcement contains certain statements that are or may be forward-looking
with respect to the financial conditions, results of operations and business
achievements/performance of Xenova, KS Biomedix and/or the Enlarged Group. By
their nature, forward-looking statements involve risk and uncertainty because
they relate to events and depend on circumstances that will occur in the future.



The attention of member firms of NASDAQ is drawn to certain UK dealing
disclosure requirements. The announcement on 31 July 2003 by KS Biomedix of the
possibility of an offer commenced an offer period in accordance with the City
Code, which is published and administered by the Panel. KS Biomedix has equity
securities traded on the London Stock Exchange. Xenova has equity securities
traded on NASDAQ and the London Stock Exchange.



The disclosure requirements are set out in more detail in Rule 8 of the City
Code. In particular Rule 8.3 of the City Code requires public disclosure of
dealings during the offer period by persons who own or control, or who would as
a result of any transaction own or control, 1 per cent. or more of any class of
relevant securities of KS Biomedix or Xenova. Relevant securities include KS
Biomedix Shares, Xenova Shares, instruments convertible into such shares and
options and derivatives referenced to any such shares. In the case of the Offer
for KS Biomedix, this requirement will apply until the first closing date 4
September 2003, or, if this is later, the date when the Offer becomes or is
declared unconditional as to acceptances or lapses.



Disclosure should be made on an appropriate form no later than 12 noon London
time on the business day following the date of the dealing transaction. These
disclosures should be sent to one of the Regulatory Information Services
approved for the purposes of the Listing Rules of the UK Listing Authority. The
Panel requests that member firms advise those of their clients who wish to deal
in the relevant securities, whether in the US or in the UK, that they may be
affected by these requirements. If there is any doubt as to their application,
the Panel should be consulted (telephone number: +44 (0)20 7638 0129, fax
number: +44 (0)20 7638 1554).



Appendix 2 contains the definitions and glossary of terms used in the
announcement.

                                   APPENDIX 1



                            conditions of the offer

                        PART A: CONDITIONS OF THE OFFER

The Offer complies with the rules and regulations of the City Code, the UKLA and
the London Stock Exchange and is subject to the following conditions:

(a)     valid acceptances being received (and not, where permitted, withdrawn)
by not later than 3.00 p.m. (London time) on 4 September 2003 (or such later
time(s) and/or date(s) as Xenova may, subject to the rules of the City Code,
decide) in respect of not less than 90 per cent. (or such lower percentage as
Xenova may decide) in nominal value of the KS Biomedix Shares to which the Offer
relates, provided that this condition will not be satisfied unless Xenova and/or
its wholly owned subsidiaries shall have acquired or agreed to acquire (whether
pursuant to the Offer or otherwise) KS Biomedix Shares carrying in aggregate
more than 50 per cent. of the voting rights then normally exercisable at a
general meeting of KS Biomedix, including for this purpose (except to the extent
otherwise agreed by the Panel) any such voting rights attaching to any KS
Biomedix Shares that are unconditionally allotted or issued before the Offer
becomes or is declared unconditional as to acceptances, whether pursuant to the
exercise of any outstanding subscription or conversion rights or otherwise; and
for this purpose:

(i)    the expression "KS Biomedix Shares to which the Offer
relates" shall be construed in accordance with sections 428 to 430F of the
Companies Act 1985, and

(ii)   KS Biomedix Shares which have been unconditionally allotted
but not issued shall be deemed to carry the voting rights which they will carry
upon issue;

(b)    the passing at an extraordinary general meeting of Xenova (or any
adjournment thereof) of such resolution or resolutions as are necessary to
approve, implement and effect the Offer and the acquisition of KS Biomedix
Shares pursuant to the Offer or otherwise;

(c)     the admission to the Official List of the New Xenova Shares (or such of
them as are due to be allotted at the time the Offer becomes or is declared
unconditional in all other respects) becoming effective in accordance with the
Listing Rules and the admission of such shares to trading on the London Stock
Exchange's market for listed securities becoming effective or (if determined by
Xenova and subject to the consent of the Panel) the UKLA agreeing to admit such
shares to the Official List and the London Stock Exchange agreeing to admit such
shares to trading subject only to:

(i)     the allotment of such shares; and/or

(ii)    the Offer becoming or being declared unconditional in all respects;

(d)     any act or event occurring which would result in TransMIDTM no longer
being capable of commercial exploitation or development;

(e)     no Third Party having intervened in any way and there not continuing to
be outstanding any statute, regulation, order or decision of any Third Party in
each case which would or might be reasonably likely (in any case to an extent
which is material in the context of the Xenova Group or the KS Biomedix Group,
as the case may be, taken as a whole) to:

(i)                   make the Offer, its implementation or the acquisition or
proposed acquisition by Xenova of any shares or other securities in, or control
of, KS Biomedix or any member of the KS Biomedix Group void, illegal or
unenforceable in any jurisdiction, or otherwise directly or indirectly restrain,
prevent, prohibit, restrict or delay the same or impose additional conditions or
obligations with respect to the Offer or such acquisition, or otherwise
materially challenge or interfere with the Offer or such acquisition, or require
material amendment to the terms of the Offer or the acquisition or proposed
acquisition of any KS Biomedix Shares or of control by Xenova of KS Biomedix or
any member of the KS Biomedix Group;

(ii)                 materially limit or delay the ability of any member of the
Xenova Group or any member of the KS Biomedix Group to acquire or to hold or to
exercise effectively, directly or indirectly, all or any rights of ownership in
respect of shares or other securities in, or to exercise voting control over,
any member of the Xenova Group or any member of the KS Biomedix Group;

(iii)                require or prevent the divestiture by Xenova of any shares
or other securities in any member of the KS Biomedix Group;

(iv)               require, prevent or delay the divestiture or alter the terms
envisaged for any proposed divestiture by any member of the Xenova Group or by
any member of the KS Biomedix Group of all or any material portion of their
respective businesses, assets or properties or impose any material limitation on
the ability of any of them to conduct any of their respective businesses or to
own or control any of their respective assets or properties or any material part
thereof;

(v)                 require any member of the Xenova Group or of the KS Biomedix
Group to acquire, or to offer to acquire, any shares or other securities (or the
equivalent) in any member of either group owned by any third party;

(vi)               materially limit the ability of any member of the Xenova
Group or of the KS Biomedix Group to conduct or integrate or co-ordinate its
business, or any material part of it, with the businesses or any part of the
businesses of any other member of the Xenova Group or of the KS Biomedix Group;

(vii)              result in any member of the KS Biomedix Group or the Xenova
Group ceasing to be able to carry on business under any name under which it
presently does so; or

(viii)            otherwise adversely affect the business, assets, profits,
financial or trading position or prospects of any member of the KS Biomedix
Group or of the Xenova Group,

and all applicable waiting and other time periods during which any Third Party
could intervene under the laws of any jurisdiction having expired, lapsed or
been terminated which may be material in the context of the offer;

(f)      none of the Office of Fair Trading, a relevant authority in the United
Kingdom or the Secretary of State for Trade and Industry having indicated that
it is their intention to refer the proposed acquisition of KS Biomedix by Xenova
to the Competition Commission;

(g)     in any case to an extent which is material in the context of the Xenova
Group or the KS Biomedix Group, as the case may be, as a whole, all
notifications and filings which are necessary having been made, all appropriate
waiting and other time periods (including any extensions of such waiting and
other time periods) under any applicable legislation or regulation of any
jurisdiction having expired, lapsed or been terminated (as appropriate) and all
statutory or regulatory obligations in any jurisdiction having been complied
with in each case in connection with the Offer, or the acquisition or proposed
acquisition of any shares or other securities in KS Biomedix or the control of
KS Biomedix or any other member of the KS Biomedix Group by Xenova or the
carrying on by any member of the KS Biomedix Group of its business;

(h)     all Authorisations which are necessary in any jurisdiction for or in
respect of the Offer, or the acquisition or proposed acquisition of any shares
or other securities in KS Biomedix, or the acquisition of control of any member
of the KS Biomedix Group by Xenova, or the carrying on by any member of the KS
Biomedix Group of its business, having been obtained from all appropriate Third
Parties or from any persons or bodies with whom any member of the KS Biomedix
Group has entered into contractual arrangements, in each case where the absence
of such Authorisation would have a material adverse effect on the Enlarged Group
taken as a whole, and all such Authorisations remaining in full force and effect
and there being no notice or intimation of any intention to revoke, suspend,
restrict, modify or not to renew any of the same;

(i)       except as fairly disclosed in KS Biomedix's annual report and accounts
for the year ended 31 May 2003 and/or as otherwise publicly announced by KS
Biomedix (by the delivery of an announcement to a Regulatory Information
Service) prior to 14 August 2003  and/or as fairly disclosed to Xenova in
writing by or on behalf of KS Biomedix prior to 14 August 2003, there being no
provision of any arrangement, agreement, licence, permit, franchise or other
instrument to which any member of the KS Biomedix Group is a party, or by or to
which any such member or any of its assets is or are or may be bound, entitled
or subject or any circumstance which, in each case as a consequence of the
Offer, or the acquisition or proposed acquisition of any shares or other
securities in KS Biomedix or the acquisition of control of any member of the KS
Biomedix Group by Xenova or otherwise, could or might reasonably be expected to
result in (in any case to an extent which is material in the context of the KS
Biomedix Group taken as a whole):

(i)                   any monies borrowed by or any other indebtedness or
liabilities (actual or contingent) of, or any grant available to, any member of
the KS Biomedix Group being or becoming repayable or capable of being declared
repayable immediately or prior to its stated repayment date or the ability of
any member of the KS Biomedix Group to borrow monies or incur any indebtedness
being withdrawn or inhibited or becoming capable of being withdrawn;

(ii)                 the creation or enforcement of any mortgage, charge or
other security interest over the whole or any part of the business, property,
assets or interests of any member of the KS Biomedix Group or any such mortgage,
charge or other security interest (wherever created, arising or having arisen)
becoming enforceable;

(iii)                the creation of new liabilities (actual or contingent) by
any member of the KS Biomedix Group that are material in the context of the KS
Biomedix Group taken as a whole;

(iv)               any such arrangement, agreement, licence, permit, franchise
or instrument, or the rights, liabilities, obligations or interests of any
member of the KS Biomedix Group thereunder being, or becoming capable of being,
terminated or materially and adversely modified or affected or any adverse
action being taken or any onerous obligation or liability arising thereunder;

(v)                 any asset or interest of any member of the KS Biomedix Group
being or falling to be disposed of or ceasing to be available to any member of
the KS Biomedix Group or any right arising under which any such asset or
interest could be required to be disposed of or could cease to be available to
any member of the KS Biomedix Group otherwise than in the ordinary course of
business;

(vi)               any member of the KS Biomedix Group ceasing to be able to
carry on business under any name under which it presently does so;

(vii)              the rights, liabilities, obligations or interests of any
member of the KS Biomedix Group under any such arrangement, agreement, licence,
permit, franchise or other instrument or the interests or business of any such
member in or with any other person, firm, company or body (or any arrangement or
arrangements relating to any such interests or business) being terminated, or
materially and adversely modified or affected; or

(viii)            the financial or trading position or the prospects or the
value of any member of the KS Biomedix Group being prejudiced or adversely
affected,

and no event having occurred which, under any provision of any such arrangement,
agreement, licence, permit or other instrument to which any member of the KS
Biomedix Group is a party or by or to which any such member or any of its assets
may be bound, could result in any of the events or circumstances which are
referred to in paragraphs (i) to (viii) of this condition (i) in any case to an
extent which is or would be material in the context of the KS Biomedix Group
taken as a whole;

(j)       except as disclosed in KS Biomedix's annual report and accounts for
the year then ended 31 May 2003 and/or as otherwise publicly announced by KS
Biomedix (by the delivery of an announcement to a Regulatory Information
Service) prior to 14 August 2003  and/or as otherwise fairly disclosed in
writing to Xenova by or on behalf of KS Biomedix prior to 14 August 2003  no
member of the KS Biomedix Group having:

(i)                   issued or agreed to issue, or authorised the issue of,
additional shares of any class, or securities convertible into or exchangeable
for, or rights, warrants or options to subscribe for or acquire, any such shares
or convertible securities other than as between KS Biomedix and wholly-owned
subsidiaries of KS Biomedix and other than any options granted under any of the
KS Biomedix Share Option Schemes prior to 14 August 2003  or any shares issued
upon the exercise of any options granted under any of the KS Biomedix Share
Option Schemes;

(ii)                 purchased or redeemed or repaid any of its own shares or
other securities or reduced or made any other change to any part of its share
capital;

(iii)                recommended, declared, paid or made any bonus, dividend or
other distribution whether payable in cash or otherwise (other than to KS
Biomedix or a wholly-owned subsidiary of KS Biomedix);

(iv)               made or authorised or announced its intention to propose any
change in its loan capital;

(v)                 (other than any acquisition or disposal in the ordinary
course of business or a transaction between KS Biomedix and a wholly-owned
subsidiary of KS Biomedix) merged with, demerged or acquired any body corporate,
partnership or business or acquired or disposed of or transferred, mortgaged or
charged or created any security interest over any assets or any right, title or
interest in any assets (including shares in any undertaking and trade
investments) or authorised, proposed or announced its intention to do the same
(which in any case is material in the context of the KS Biomedix Group taken as
a whole);

(vi)               issued or authorised the issue of, or made any change in or
to, any debentures or (except in the ordinary course of business) incurred or
increased any indebtedness or liability (actual or contingent) which in any case
is material in the context of the KS Biomedix Group taken as a whole;

(vii)              entered into, varied, or authorised any agreement,
transaction, arrangement or commitment (whether in respect of capital
expenditure or otherwise) which:

         i.      is of a long term, onerous or unusual nature or magnitude or 
which is or might reasonably be expected to involve an obligation of such nature 
or magnitude; or

         ii.     could materially restrict the business of any member of the KS 
Biomedix Group; or

         iii.     is other than in the ordinary course of business,

and which in any case is material in the context of the KS Biomedix Group taken
as a whole;

(viii)            entered into, implemented, effected or authorised any merger,
demerger, reconstruction, amalgamation, scheme, commitment or other transaction
or arrangement in respect of itself or another member of the KS Biomedix Group
otherwise than in the ordinary course of business which in any case is material
in the context of the KS Biomedix Group taken as a whole;

(ix)                entered into or varied the terms of any contract, agreement
or arrangement with any of the directors of KS Biomedix or, to an extent which
is material in the context of the KS Biomedix Group taken as a whole, the
directors or senior executives of any member of the KS Biomedix Group;

(x)                  taken any corporate action or had any legal proceedings
instituted or threatened against it or order made for its winding-up
(voluntarily or otherwise), dissolution or reorganisation or for the appointment
of a receiver, administrator, administrative receiver, trustee or similar
officer of all or any part of its assets and revenues or any analogous
proceedings in any jurisdiction or appointed any analogous person in any
jurisdiction which in any case is material in the context of the KS Biomedix
Group taken as a whole;

(xi)                been unable, or admitted in writing that it is unable, to
pay its debts or having stopped or suspended (or threatened to stop or suspend)
payment of its debts generally or ceased or threatened to cease carrying on all
or a substantial part of its business;

(xii)               waived or compromised any claim other than in the ordinary
course of business which is material in the context of the KS Biomedix Group
taken as a whole;

(xiii)             made any alteration to its memorandum or articles of
association which is material in the context of the Offer;

(xiv)             made or agreed or consented to any significant change to the
terms of the trust deeds constituting the pension schemes established for its
directors and/or employees and/or their dependants or to the benefits which
accrue, or the pensions which are payable thereunder, or to the basis on which
qualification for or accrual or entitlement to such benefits or pensions are
calculated or determined, or to the basis upon which such liabilities (including
pensions) of such pensions schemes are funded or made, or agreed or consented
to, any change to the trustees, in each case which is material; or

(xv)              entered into any agreement, commitment or arrangement or
passed any resolution or made any offer (which remains open for acceptance) or
announced any intention with respect to any of the transactions, matters or
events referred to in this condition (i) which is material in the context of the
KS Biomedix Group taken as a whole;

(k)     except as disclosed in KS Biomedix's annual report and accounts for the
year then ended 31 May 2003 and/or as otherwise publicly announced by KS
Biomedix (by the delivery of an announcement to a Regulatory Information
Service) prior to 14 August 2003  and/or as otherwise fairly disclosed in
writing to Xenova by or on behalf of KS Biomedix prior to 14 August 2003:

(i)                   there having been no adverse change or deterioration in
the business, assets, financial or trading positions or profits or prospects of
any member of the KS Biomedix Group which in any case is material in the context
of the KS Biomedix Group taken as a whole;

(ii)                 no contingent or other liability of any member of the KS
Biomedix Group having arisen or become apparent or increased which in any case
is material in the context of the KS Biomedix Group taken as a whole;

(iii)                no litigation, arbitration proceedings, prosecution or
other legal proceedings (including patent proceedings and US patent interference
proceedings) to which any member of the KS Biomedix Group is or may become a
party (whether as plaintiff, defendant or otherwise) having been threatened,
announced, implemented or instituted by or against or remaining outstanding
against or in respect of any member of the KS Biomedix Group which in any case
is material in the context of the KS Biomedix Group taken as a whole;

(iv)               (other than as a result of the Offer) no enquiry or
investigation by, or complaint or reference to, any Third Party having been
threatened, announced, implemented, instituted by or against or remaining
outstanding against or in respect of any member of the KS Biomedix Group which
in any case is material in the context of the KS Biomedix Group taken as a
whole;

(v)                 no circumstances having arisen which would entitle a third
party to take patent infringement proceedings against a member of the KS
Biomedix Group which would be material in the context of the KS Biomedix Group
taken as a whole; and

(vi)               no agreement to which any member of the KS Biomedix Group is
a party and which would be material in the context of the KS Biomedix Group
taken as a whole having been terminated by any other party to any such
agreement;

(l)       Xenova not having discovered (save as fairly disclosed in writing by
or on behalf of KS Biomedix to Xenova prior to 14 August 2003):

(i)                   that any financial or business or other information
concerning the KS Biomedix Group disclosed at any time by or on behalf of any
member of the KS Biomedix Group, whether publicly or in writing (including
without limitation information transmitted by facsimile, telex or e-mail) to any
member of the Xenova Group or its advisers is materially misleading or contains
any misrepresentation of fact or omits to state a fact necessary to make any
information contained therein not materially misleading and which was not
subsequently corrected before 14 August 2003  by written disclosure to Xenova,
to an extent which in any case is material in the context of the KS Biomedix
Group taken as a whole; or

(ii)                 that any member of the KS Biomedix Group is subject to any
liability (actual or contingent) except as disclosed in KS Biomedix's annual
report and accounts for the financial year ended 31 May 2003 and/or as otherwise
publicly announced by KS Biomedix (by the delivery of an announcement to a
Regulatory Information Service) prior to 14 August 2003  and which in any case
is material in the context of the KS Biomedix Group taken as a whole; or

(iii)                any information which affects the import of any information
disclosed at any time by or on behalf of any member of the KS Biomedix Group
which is material in the context of the KS Biomedix Group taken as a whole; and

(m)    Xenova not having discovered (save as fairly disclosed in writing by or
on behalf of KS Biomedix to Xenova prior to 14 August 2003) that:

(i)                   any past or present member of the KS Biomedix Group has
not complied with any applicable legislation or regulations of any jurisdiction
with regard to the use, treatment, handling, storage, transport, release,
disposal, discharge, spillage, leak or emission of any waste or hazardous
substance or any substance likely to impair the environment or harm human
health, or otherwise relating to environmental matters or the health and safety
of any person, and that there has not otherwise been any such use, treatment,
handling, storage, transport, release, disposal, discharge, spillage, leak or
emission (whether or not this constituted a noncompliance by any person with any
legislation or regulations and wherever the same may have taken place) which, in
any case, would be likely to give rise to any liability (whether actual or
contingent) or cost on the part of any member of the KS Biomedix Group which in
any case is material in the context of the KS Biomedix Group taken as a whole;

(ii)                 there is, or is likely to be, any liability, whether actual
or contingent, to make good, repair, reinstate or clean up any property now or
previously owned, occupied or made use of by any past or present member of the
KS Biomedix Group or any other property or any controlled waters under any
environmental legislation, regulation, notice, circular, order or other lawful
requirement of any relevant authority or third party or otherwise which in any
case is material in the context of the KS Biomedix Group taken as a whole; or

(iii)                circumstances exist whereby a person or class of persons
would be likely to have a claim in respect of any product or process of
manufacture or materials used therein now or previously manufactured, sold or
carried out by any past or present member of the KS Biomedix Group which is or
would be material in the context of the KS Biomedix Group taken as a whole.



For the purpose of these conditions:



(a)        "a Regulatory Information Service" has the meaning given to it in
Schedule 12 of the Listing Rules;

(b)        "Third Party" means any government, government department or
governmental, quasi governmental, supranational, statutory, regulatory or
investigative body, authority (including any national anti-trust or merger
control authority), court, trade agency, association, institution or
professional or environmental body or any other person or body whatsoever in any
jurisdiction;

(c)        a Third Party shall be regarded as having "intervened" if it has
decided to take, institute, implement or threaten any action, proceeding, suit,
investigation, enquiry or reference or made, proposed or enacted any statute,
regulation, decision or order or taken any measures or other steps or required
any action to be taken and "intervene" shall be construed accordingly;

(d)    "Authorisations" means authorisations, orders, grants, recognitions,
determinations, certificates, confirmations, consents, licences, clearances,
provisions and approvals;

(e)        "Xenova Group" in these conditions shall, for the avoidance of doubt,
include Phogen Limited; and

(f)         "KS Biomedix Group" in these conditions shall, for the avoidance of
doubt, include Discerna

Limited.



Subject to the requirements of the Panel, Xenova reserves the right to waive all
or any of the above conditions, in whole or in part, except conditions (a) to
(c).



Conditions (d) to (m) (inclusive) must be fulfilled, be determined by Xenova to
be or remain satisfied or (if capable of waiver) be waived by midnight on the
21st day after the later of 4 September 2003  and the date on which condition
(a) is fulfilled (or in each case such later date as Xenova may, with the
consent of the Panel, decide), failing which the Offer will lapse. Xenova shall
be under no obligation to waive (if capable of waiver), to determine to be or
remain satisfied or to treat as fulfilled any of conditions (d) to (m)
(inclusive) by a date earlier than the latest date specified above for the
fulfilment of that condition.



If the Panel requires Xenova to make an offer for KS Biomedix Shares under the
provisions of Rule 9 of the City Code, Xenova may make such alterations to the
conditions of the Offer, including to condition (a), as are necessary to comply
with the provisions of that Rule.



The Offer will lapse (unless otherwise agreed by the Panel) if the acquisition
of KS Biomedix is referred to the Competition Commission before the later of
3.00 p.m. on the first closing date of the Offer and the date when the Offer
becomes or is declared unconditional as to acceptances.



If the Offer lapses it will cease to be capable of further acceptance. KS
Biomedix Shareholders who have accepted the Offer and Xenova shall then cease to
be bound by acceptances delivered on or before the date on which the Offer
lapses.





APPENDIX 2



DEFINITIONS



The following definitions apply throughout this announcement, unless the context
requires otherwise:


"Acquisition"                  the proposed acquisition of KS Biomedix by Xenova by way of the Offer

"Act"                          Companies Act 1985, as amended

"Approved CSOP"                the Inland Revenue approved company share option plan adopted by KS Biomedix on
                               17 September 2002

"Babraham"                     Babraham Broscience Technologies Limited

"Cantab"                       Cantab Pharmaceuticals plc

"Celltech"                     Celltech Group plc

"Circular"                     the circular dated 14 August 2003 addressed to Xenova Shareholders

"City Code" or "Code"          The City Code on Takeovers and Mergers

"clinical trials"              research study conducted with patients, usually to evaluate a new treatment or
                               drug

"Closing Price"                the closing middle-market price of a KS Biomedix Share or a Xenova Share, as
                               the case may be, as derived from the Daily Official List

"Commercially Sold"            shall mean sold commercially in a Relevant Territory and generally available
                               for purchase by clinics and/or hospitals in a Relevant Territory

"CREST"                        the United Kingdom paperless share settlement system of which CRESTCo Limited
                               is the Operator (as such term is defined in the Regulations)

"Deferred Consideration"       new Xenova Shares to the value of 10 pence for each KS Biomedix Share, to be
                               issued in accordance with the terms and conditions set out in paragraph 12 of
                               this announcement

"Discerna"                     Discerna Limited

"DNA"                          deoxy ribonucleic acid, the chemical basis of genes

"drug candidate"               a drug lead that has been optimised and has been selected to enter preclinical
                               development and clinical trials

"EGM" or "Extraordinary        the extraordinary general meeting of Xenova to be held at the offices of SJ
General Meeting"               Berwin, 222 Grays Inn Road, London, WC1X 8XF at 10.00 a.m. on 1 September 2003,
                               or any adjournment or postponement thereof, notice of which is set out in the
                               Circular

"Employee Share Option Scheme" The KS Biomedix Holdings plc 1997 Employee Share Option Scheme, a discretionary
                               share option scheme of KS Biomedix operated pursuant to rules adopted on 13
                               October 1997

"Enlarged Group"               Xenova or the Xenova Group (as the context requires) as enlarged by the
                               acquisition of KS Biomedix

"EU"                           the European Union

"Exchangeable Shares"          7,119,029 shares in the capital of Exchangeco exchangeable into ordinary shares
                               in KS Biomedix

"Exchangeco"                   KS Canada Inc., a company incorporated under the Business Corporations Act (New
                               Brunswick) 1981 which is an indirect subsidiary of KS Biomedix

"FDA"                          The Food and Drug Administration of the US

"Form of Acceptance"           the form of acceptance relating to the Offer

"Genentech"                    Genentech, Inc.

"glioma"                       any of the largest group of primary tumours of the brain, composed of malignant
                               glial cells

"GMCSF"                        Granulocyte macrophage colony stimulating factor, an immune system stimulating
                               protein

"HPV"                          human papilloma virus, believed to be a causal factor in a number of
                               ano-genital cancers

"Individual Option Agreements" the agreements between KS Biomedix and certain of its employees (including
                               certain KS Biomedix Directors) pursuant to which certain options over KS
                               Biomedix Shares have been granted

"KS Biomedix"                  KS Biomedix Holdings plc

"KS Biomedix Board" or "KS     the existing directors of KS Biomedix
Biomedix Directors"

"KS Biomedix Group"            KS Biomedix and its existing subsidiaries and subsidiary undertakings

"KS Biomedix Issued Share      the existing unconditionally allotted or issued fully paid ordinary shares of 2
Capital"                       pence each in the share capital of KS Biomedix as at the date of this document
                               including any shares allotted as a consequence of the exchange of the
                               Exchangeable Shares and the issue of the Remuneration Shares

"KS Biomedix Shareholders"     holders of KS Biomedix Shares

"KS Biomedix Share Option      the Approved CSOP, the Employee Share Option Scheme, the Individual Option
Schemes"                       Agreements and the Unapproved CSOP

"KS Biomedix Shares"           the existing unconditionally allotted or issued fully paid ordinary shares of 2
                               pence each in the share capital of KS Biomedix and any further ordinary shares
                               which are unconditionally allotted or issued including any shares allotted as a
                               consequence of the exchange of the Exchangeable Shares and the issue of
                               Remuneration Shares at or before the time at which the Offer ceases to be open
                               for acceptance (or such earlier date and/or time, not being earlier than the
                               date on which the Offer becomes or is declared unconditional as to acceptances
                               or, if later, the first closing date of the Offer, as Xenova may, subject to
                               the City Code, decide)

"Lilly"                        Eli Lilly and Company of Indianapolis, US

"Listing Particulars"          the listing particulars of Xenova dated 14 August 2003

"London Stock Exchange"        London Stock Exchange plc

"Medison"                      Medison Pharma, Ltd.

"Millennium"                   Millennium Pharmaceuticals, Inc.

"MRP"                          multidrug resistance protein

"New Xenova Shares"            up to 71,545,305 new Xenova Shares proposed to be issued fully paid pursuant to
                               the Offer comprising 69,187,900 new Xenova Shares to be issued in respect of
                               the KS Biomedix Shares Issued Share Capital (but excluding any shares that
                               might be issued in respect of the Deferred Consideration) and up to
                               2,357,405new Xenova Shares which may be issued pursuant to the Offer following
                               the exercise of options under the KS Biomedix Share Option Schemes

"NIDA"                         National Institute on Drug Abuse (US)

"Nomura"                       Nomura International plc, financial adviser, sponsor and broker to Xenova

"Nycomed"                      Nycomed Danmark AS

"Offer"                        the recommended offer by Nomura on behalf of Xenova to acquire the KS Biomedix
                               Shares on the terms and subject to the conditions set out in the Offer Document
                               and the Form of Acceptance including, save where the context requires
                               otherwise, any subsequent revision, variation, extension or renewal of such
                               offer

"Offer Document"               the document dated 14 August 2003 detailing the terms and conditions of the
                               Offer including the appendices thereto

"Offer Period"                 the period commencing on (and including) 31 July 2003 until the later of: (i)
                               3pm on 4 September 2003, (ii) the date on which the Offer becomes unconditional
                               and (iii) the date on which the Offer lapses

"Official List"                the Official List of the UKLA

"PAI-1"                        plasminogen activator inhibitor, a protein released by platelets and cells
                               lining the blood vessels which regulates the blood clot clearance system in
                               humans

"Panel"                        The Panel on Takeovers and Mergers

"Pfizer"                       Pfizer Inc.

"Phase I"                      a clinical trial with the objective of evaluating the safety and tolerability
                               of a drug candidate

"Phase II"                     a clinical trial with the objective of evaluating the safety and preliminary
                               efficacy of a drug candidate

"Phase III"                    a clinical trial with the objective of evaluating the definitive safety and
                               efficacy of a drug candidate

"Phogen"                       Phogen Limited

"preclinical"                  the testing of an experimental drug, in vitro or in animals, before regulated
                               clinical trials are carried out

"Proposed Directors"           Mr John Rennocks and Dr Michael Young who are to be appointed directors of
                               Xenova following the Acquisition

"QLT"                          QLT Inc.

"Ranbaxy"                      Ranbaxy Laboratories Limited

"Relevant Territory"           either the United States or any three EU countries

"Remumeration Shares"          75,364 ordinary shares of 2 pence each in the share capital of KS Biomedix to
                               be issued to Mr. John Rennocks, non-executive Chairman of KS Biomedix, on the
                               date of this document pursuant to the terms of his appointment as non-executive
                               Chairman of KS Biomedix

"Rothschild"                   N M Rothschild & Sons Limited, financial adviser to KS Biomedix in respect of
                               the Offer

"Sosei"                        Sosei Co., Ltd.

"therapeutic area"             a group of diseases or conditions, generally all belonging to the same
                               physiological system or treated with similar drugs

"UK" or "United Kingdom"       the United Kingdom of Great Britain and Northern Ireland

"UKLA"                         the UK Listing Authority, being the Financial Services Authority acting in its
                               capacity as the competent authority for the purposes of Part VI of the
                               Financial Services and Markets Act 2000

"Unapproved CSOP"              the unapproved KS Biomedix share option plan adopted by KS Biomedix on 17
                               September 2002

"US", "USA" or "United States" the United States of America, its territories and possessions, any state of the
                               United States of America and the District of Columbia

"US Persons"                   a US person as defined in Rule 902 under the United States Securities Act 1933,
                               as amended

"Valuation Period"             the period of 20 dealing days including and immediately following the date of
                               the first announcement by Xenova that regulatory approval or marketing
                               authorisation of TransMIDTM in the US, the EU or any three EU countries has
                               been obtained

"Xenova" or the Company"       Xenova Group plc

"Xenova Board" or "Xenova      the existing board of directors of Xenova
Directors"

"Xenova Group"                 Xenova and its subsidiaries and subsidiary undertakings from time to time

"Xenova Shareholders"          holders of Xenova Shares

"Xenova Share Option Schemes"  the Xenova Limited 1988 Share Option Scheme, the Xenova Group 1992 Share Option
                               Scheme, the Xenova Group 1996 Share Option Scheme, the Xenova Group 1996
                               Savings Related Share Option Plan, and the Xenova Deferred Share Bonus Plan

"Xenova Shares" or "Ordinary   ordinary shares with a nominal value of 10 pence each in the share capital of
Shares"                        Xenova, or ordinary shares into which any such ordinary shares may, from time
                               to time, be subdivided or consolidated


APPENDIX 3


SOURCES OF INFORMATION AND BASES OF CALCULATION



(i)                   The value of the Offer is based on the KS Biomedix Issued
Share Capital, being the aggregate of 57,382,702 KS Biomedix Shares (being the
number of KS Biomedix Shares in issue on 13 August 2003), the Exchangeable
Shares and the Remuneration Shares.

(ii)                 The percentage ownership of the Enlarged Group held by
Xenova Shareholders and KS Biomedix Shareholders is based on the enlarged issued
share capital of Xenova following the Offer, being the aggregate of 174,533,588
Xenova Shares in issue on 13 August 2003 (as sourced from the Xenova register of
members) and 69,187,900 New Xenova Shares to be issued to KS Biomedix
Shareholders pursuant to the Offer.  This assumes no exercise of options under
the Xenova Share Option Schemes or the KS Biomedix Share Option Schemes or issue
of shares in respect of Deferred Consideration and assumes acceptance in full of
the Offer.

(iii)                The financial information relating to KS Biomedix is
extracted from its audited accounts for the year ended 31 May 2003.

(iv)               The financial information relating to Xenova is extracted
from its unaudited interim results for the six months ended 30 June 2003.

(v)                 The Closing Prices of Xenova and KS Biomedix Shares are
derived from the Daily Official List.




                      This information is provided by RNS
            The company news service from the London Stock Exchange
END

OFFQZLBFXVBXBBD