SLRN ACELYRIN Inc

ACELYRIN, INC. (Nasdaq: SLRN), a late-stage clinical biopharma company focused on accelerating the development and delivery of transformative medicines in immunology, today announced that positive results from the company’s global Phase 2b/3 clinical trial of izokibep in psoriatic arthritis (PsA) will be shared as a late breaking oral presentation at the 2024 European Alliance of Associations for Rheumatology Congress taking place June 12-15 in Vienna, Austria. Izokibep is a small protein therapeutic designed to inhibit IL-17A, a validated mechanism for the treatment of PsA and other immune-mediated diseases.

Presentation details are as follows:

Title: Efficacy and Safety of Izokibep, a Novel IL-17A Inhibitor, in Patients with Active Psoriatic Arthritis: Week 16 Results from a Randomized, Double-Blind, Placebo-Controlled, Multicenter Phase 2b/3 StudyDate/Time: Saturday, June 15, 2024; 9:30am - 9:40am CESTPresenter: Philip Mease, MD, MACR, Director of Rheumatology Research at Swedish Medical Center

About the Phase 2b/3 Psoriatic Arthritis clinical trialThe Phase 2b/3 clinical trial (NCT05623345) is a global, multi center, randomized double-blind, placebo-controlled trial evaluating the safety and efficacy of izokibep dosed subcutaneously 160 mg every week (QW) or every two weeks (Q2W) and 80 mg every four weeks (Q4W) versus placebo. 351 adult patients with active PsA were enrolled across 71 sites in the United States and Europe and randomized across the four arms.

For more information about the Phase 2b/3 PsA clinical trial, please visit www.clinicaltrials.gov.

About Psoriatic ArthritisPsoriatic arthritis (PsA) is a chronic immune-mediated inflammatory disease characterized by multiple manifestations including destructive joint inflammation, psoriasis, and enthesitis (painful inflammation of the small, dense tissues that connect ligament and tendons to bone), all contributing to reduced quality of life. It is estimated that approximately 30% of the 125 million people living with psoriasis worldwide will also develop PsA over time. There remains a large unmet need for more effective therapies to treat PsA across all disease manifestations.

About IzokibepIzokibep is a small protein therapeutic designed to inhibit IL-17A with high potency through tight binding affinity, providing the potential for robust tissue penetration due to its small molecular size, about one-tenth the size of a monoclonal antibody, and an albumin binding domain that extends half-life. Clinical trial data supports the hypothesis that these unique characteristics of izokibep may provide clinically meaningful and differentiated benefits for patients, including resolution of key manifestations of disease. Izokibep is being evaluated in multiple late-stage trials in moderate-to-severe hidradenitis suppurativa (HS), psoriatic arthritis (PsA), and uveitis, with plans to initiate an additional Phase 3 program in axial spondyloarthritis (AxSpA).

About ACELYRIN, INC.ACELYRIN, INC. (Nasdaq: SLRN) is a Los Angeles area-based late-stage clinical biopharma company – with additional operations in the San Francisco Bay area – focused on providing patients life-changing new treatment options by identifying, acquiring, and accelerating the development and commercialization of transformative medicines. ACELYRIN has two programs in late-stage clinical development. Lonigutamab is a subcutaneously delivered monoclonal antibody targeting IGF-1R advancing into Phase 2b/3 development for the treatment of thyroid eye disease. Izokibep is a next generation inhibitor of IL-17A in Phase 2b/3 development for the treatment of psoriatic arthritis, hidradenitis suppurativa and uveitis.

For more information about ACELYRIN, visit us at www.acelyrin.com or follow us on LinkedIn and X.

Forward Looking Statements This press release contains forward-looking statements including, but not limited to, statements related to the potential future success of ACELYRIN’s izokibep program; anticipated development activities including the planned initiation and timing of clinical trials; the therapeutic potential of ACELYRIN’s product candidates, including the ability for such product candidates to offer clinically meaningful, differentiated benefits including resolution of key manifestations of disease, and including clinical benefits that may improve over time; and other statements that are not historical fact. These forward-looking statements are based on ACELYRIN’s current plans, objectives and projections, and are inherently subject to risks and uncertainties that may cause ACELYRIN’s actual results to materially differ from those anticipated in such forward-looking statements. Such risks and uncertainties include, without limitation, those associated with the successful completion of development and regulatory activities with respect to ACELYRIN’s product candidates; the timing and results of ACELYRIN’s clinical trials, including the risk that future clinical trial results could differ materially and adversely from prior clinical trial results or data; maintaining and defending intellectual property protection; delays or failures to secure adequate supply of its product candidates; ACELYRIN’s failure to realize the expected benefits of its acquisition of additional programs; legal proceedings and other risks and uncertainties affecting ACELYRIN including those described from time to time under the caption “Risk Factors” and elsewhere in ACELYRIN’s current and future reports filed with the Securities and Exchange Commission, including its Quarterly Report on Form 10-Q for the quarter ended March 31, 2024. Forward-looking statements contained in this press release are made as of this date, and ACELYRIN undertakes no duty to update such information except as required under applicable law.

ACELYRIN Contacts:Tyler MarciniakVice President of Investor Relations,Communications and Advocacyinvestors@acelyrin.com media@acelyrin.com