Conflicting Erbitux Study Data Hurts Merck Shares
23 September 2009 - 4:22PM
Dow Jones News
Conflicting study data about Merck KGaA's (MRK.XE) key cancer
drug proved a rollercoaster for shares of the German pharmaceutical
company Wednesday.
Shares fell Wednesday afternoon after an independent study
showed Erbitux failed to improve survival rates in colon cancer
patients compared with standard chemotherapy.
The results seemed to contradict a Merck study published earlier
in the day - which sent shares up - that showed colon cancer
patients lived 3.5 months longer on Erbitux compared with
chemotherapy.
Analysts say confusion about the data weighed on the shares. At
1331 GMT, the shares were down EUR2.75, or 4%, at EUR66.02, while
the DAX was up 0.2%.
The independent COIN study showed patients who received Erbitux
lived a median rate of 17 months, compared with 17.9 months for
those on chemotherapy alone, and wasn't statistically
significant.
Earlier Wednesday, Merck said data from a trial called CRYSTAL
showed colon cancer patients lived 3.5 months longer - 23.5 months
compared with 20 months - when Erbitux was added to their
chemotherapy treatment.
The drug is already approved for colon cancer in the U.S. and
Europe so the data have no impact on where the drug is sold.
However, the data could give competitors such as Amgen Inc.'s
(AMGN) Vectibix a marketing edge depending on how the market
interprets the results.
"The difference between the CRYSTAL and COIN studies lies in
that one was commissioned by the company; the other was
independent," said Sal. Oppenheim analyst Peter Duellmann.
However, Duellmann said the CRYSTAL data have greater meaning
and higher clinical relevance.
The results were presented at the European Society for Medical
Oncology congress in Berlin.
Erbitux, a monoclonal antibody whose active ingredient is called
cetuximab, is already approved as a primary treatment in
combination with chemotherapy for colon cancer. Analysts consider
the drug a potential blockbuster, with peak annual sales of at
least EUR1 billion. It is marketed in the U.S. by Eli Lilly &
Co. (LLY) and Bristol-Myers Squibb Co. (BMY).
"The COIN study is disappointing for us because we couldn't
reach the primary endpoint of showing an advantage in overall
survival," Wolfgang Wein, executive vice president of oncology for
Merck's pharmaceutical division, Merck Serono, told Dow Jones
Newswires in an interview Wednesday.
Wein attributed the difference between the studies to a weakened
patient population in the COIN study.
The independent COIN study included about 2,400 colon cancer
patients and had three arms: a group of patients who continued
receiving oxaliplatin-based chemotherapy; a group who received
Erbitux and oxaliplatin therapy; and a third group who received
oxaliplatin-based chemotherapy intermittently.
Wein said patients in the Erbitux arm were given significantly
less chemotherapy.
"Additionally we've seen that significantly less chemotherapy
was given in the Erbitux arm and also in the second-line therapy so
that the Erbitux effects apparently washed off," he said.
Wein said the company must analyze the therapy strategy for the
study for older, weaker patients.
"We must understand exactly what occurred in the study, and what
it means for our general treatment strategy when significantly less
chemotherapy was given in the Erbitux arm and furthermore for
patients in very bad shape."
-By Heide Oberhauser-Aslan and Allison Connolly, Frankfurt
Bureau; +49 69 29725500; heide.oberhauser@dowjones.com