Positive New Results for Treatment of Psoriatic Arthritis

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.