• Top range efficacy for ACR and PASI scores
  • Proportion of patients with resolution of enthesitis appears differentiating
  • Supports hypothesis that izokibep offers greater efficacy with high potency and small size
  • Supports strategy of evaluating IL-17A inhibition’s potential for transformative efficacy across many disease states
  • Study results to be presented at EULAR in Copenhagen, on June 3, 2022

LOS ANGELES, CA, USA; SOLNA, Sweden, and SHANGHAI, China I May 3, 2022 I ACELYRIN, INC., Affibody AB, and Inmagene Biopharmaceuticals Co., Ltd., today announced that a 16-week, global, Phase 2 clinical trial of izokibep in 135 patients with psoriatic arthritis (PsA) met its primary endpoint of ACR50. Izokibep also achieved secondary endpoints, including PASI response, enthesitis LEEDs improvement, and quality of life improvement on a clinically validated PsA-specific quality of life instrument, the Psoriatic Impact of Disease (PsAID) questionnaire.

The randomized double-blind, placebo-controlled, Phase 2 clinical trial evaluated the safety and efficacy of izokibep dosed 80 mg every two weeks (Q2W) or 40 mg Q2W, versus placebo Q2W, in adult patients with active PsA. The primary endpoint of ACR50 and secondary endpoint of PASI responses were met and were at the top of the range of responses, compared to what has been reported for other medicines approved or in development for PsA. The proportion of patients with resolution of enthesitis appears to be differentiating. A clinically meaningful improvement in disease-specific quality of life was achieved with the patient-reported outcome measure, PsAID. No new safety issues were identified.

“The positive data generated in this Phase 2 trial supports our hypothesis that the high potency and small molecular size of izokibep results in potential for greater exposures and, therefore, greater efficacy. Enhanced drug penetration in dense, poorly vascularized entheseal tissues would be consistent with the differentially greater pain reductions seen with izokibep treatment,” said Paul Peloso, MD, chief medical officer (CMO) of ACELYRIN.

“Residual entheseal pain is associated with more severe disease and poorer quality of life. It is exciting to see such improved resolution of enthesitis and patients’ improved quality of life,” he added. 

“Psoriatic arthritis is a painful and debilitating inflammatory disease of the peripheral joints, skin, and nails, and it also can affect the spine. We are pleased this Phase 2 trial highlights the potential of izokibep to offer clinically differentiated efficacy in this area of continued unmet need,” noted Prof. Nikolai Brun, MD, PhD, CMO of Affibody. “Importantly, an opportunity remains to continue to explore higher exposures to optimize response and still deliver izokibep as single SC injections.”

Shao-Lee Lin, MD, PhD, co-founder and CEO of ACELYRIN, said, “These data underscore our confidence in the previously announced strategy of fully evaluating IL-17A inhibition’s potential for transformative efficacy across many disease states.”

“The PsA P2 data have positive implications in particular for axial spondyloarthritis (AxSpA) and psoriasis (PsO), given impact on enthesitis and PASI responses. Higher dosing (160mg QW) and Q2W dosing of izokibep will be studied in a PsA P2b/3 pivotal study as a next step in advancement of the program,” she added.

David Bejker, CEO of Affibody, said, “These study results are important in demonstrating the opportunity to create best-in-class compounds based on the Affibody® technology.”

Details of the PsA Phase 2 trial data will be shared by podium presentation at the European Alliance of Associations for Rheumatology (EULAR) Congress in Copenhagen on June 3, 2022, at 11:05AM CET.

ACELYRIN holds worldwide rights to izokibep except development and commercialization rights by Inmagene in selected Asian countries, including China, Hong Kong, South Korea, and Taiwan, and excluding Japan. Affibody holds commercialization rights in the Nordic countries.

About izokibep
Izokibep is a unique, antibody mimetic, interleukin-17A (IL-17A) inhibitor designed to overcome the limitations of monoclonal antibodies. With extraordinary potency and small molecular size, izokibep can reach high drug exposure levels through a single, subcutaneous injection that monoclonal antibodies require IV administration to achieve. In addition, the small size of izokibep—about a tenth the size of a monoclonal antibody—also enables its potential to reach targeted tissues that may otherwise be inaccessible to the much larger monoclonal antibodies.

About Psoriatic Arthritis
Psoriatic arthritis (PsA) is a chronic, immune-mediated inflammatory musculoskeletal condition affecting the peripheral joints, the skin (with psoriasis), the nails, and in approximately 30 percent of individuals, the spine. Left under-treated, PsA leads to chronic joint pain, swelling, and damage with a high potential for permanent disability. Psoriatic arthritis pathology is dominated by pro-inflammatory T-helper (Th-17) cells that lead to over expression of IL-17, IL-23, and TNF cytokines.

ACELYRIN, INC. is a Los Angeles area-based biopharma company focused on providing patients life-changing new treatment options by identifying, acquiring, and accelerating development and commercialization of promising drug candidates and leveraging its expertise to rapidly advance these medicines to patients. For more information, please visit www.acelyrin.com

About Affibody AB
Affibody AB is a clinical-stage biopharmaceutical company with a broad product pipeline focused on developing innovative bi- and multi-specific next generation biopharmaceuticals based on its unique proprietary technology platforms: Affibody® molecules and Albumod®. Affibody AB is a holding of Patricia Industries. For more information, please visit www.affibody.com

About Inmagene Bio
Inmagene Biopharmaceuticals, Ltd., with wholly owned subsidiaries in San Diego, Shanghai, Hangzhou, and Wuhan, is a leading biotech company focused on immunology-related therapeutic areas. Believing in “borderless innovation”, the Inmagene team integrates efficient resources worldwide to develop drugs for patients globally. Inmagene is operating twelve “Smart Innovation” programs to create and develop novel drug candidates for the global market. For more information, please visit www.inmagenebio.com.