November 08, 2022

ACELYRIN, INC. Announces Phase 2 Data for Izokibep in Psoriatic Arthritis That Demonstrate Broad Clinical Efficacy – including in Difficult-to-Treat Manifestations – Driving Meaningful Benefits for Patients Such as Improved Pain, Sleep, and Physical Function

  • Newly reported data in key disease manifestations including dactylitis and nail lesions to be presented at the American College of Rheumatology (ACR) Convergence 2022
  • Combined with previously reported differentiated data on enthesitis and top- end efficacy on arthritis and psoriasis, these data also showed that improving efficacy in these hard-to-treat areas drove consistent, statistically significant and clinically important improvements across multiple measures of disease activity including DAS28-CRP, DAPSA and MDA
  • In totality, these improvements in efficacy and reduced disease activity drove improvements across health-related quality of life and physical function, as measured by the Psoriatic Arthritis Impact of Disease Questionnaire and its sub-domains, as well as the SF-36 and the Health Assessment Questionnaire, also to be presented at ACR
  • As predicted, these improvements with izokibep drove the greatest gains in quality of life for those patients with the highest burden of disease

LOS ANGELES, November 8, 2022 - ACELYRIN, INC., a late-stage clinical biopharma company focused on accelerating the development and delivery of transformative medicines in immunology, today announced additional data from a phase 2 trial of izokibep in psoriatic arthritis (PsA) to be presented at the American College of Rheumatology (ACR) Convergence 2022. Izokibep is a unique interleukin- 17A (IL-17A) inhibitor designed to overcome the limitations of monoclonal antibodies by utilizing high potency and small molecular size to enable high drug exposure levels through a single, subcutaneous injection that monoclonal antibodies require IV administration to achieve.

The additional data presented at ACR Convergence 2022 showing top-of-the range improvements in all key manifestations of disease, including arthritis, psoriasis, dactylitis, nail psoriasis adds to the evidence of differentiated efficacy in enthesitis previously reported at the 2022 European Alliance of Associations for Rheumatology (EULAR) Congress. The clinical improvements in these hard-to-treat areas, along with consistent, clinically important and statistically significant disease activity improvements as measured by ACR50, PASI75, DAS-28, Minimal Disease Activity, and DAPSA predictably led to important improvements in patient-reported Quality of life (QoL) on the SF-36, HAQ-DI and PsA-specific validated instrument, the PsAID, across all domains including pain, sleep disturbance, physical function and coping.

Those with the largest improvements in clinical outcome measures had the largest gains in health-related quality of life, including each of the individual sub-domains of the PsAID.

“Psoriatic arthritis is a disease of multiple clinical manifestations including enthesitis, joint pain, skin lesions and dactylitis. Improvement broadly across all of the aspects of disease drives reduction in overall disease activity, and, as expected, also improves overall quality of life – helping patients feel better and function better – which is our goal as drug developers,” said Shao-Lee Lin, MD, PhD, Co-founder and CEO, ACELYRIN. “As the ACR and EULAR data show, izokibep demonstrates top-end efficacy in joints and skin, but it’s not just about joints and skin. Further improving difficult-to-treat endpoints like enthesitis in a differentiated way leads to minimizing the overall disease burden and therefore leads to greater improvements in quality of life for patients. The data continue to validate our hypothesis that izokibep offers differentiated efficacy with high potency and small size, and reinforces izokibep’s potential to manage the hard-to-treat manifestations of PsA. The consistency of the clinical outcome and health-related quality of life measures only strengthens our enthusiasm for the ongoing phase 2b/3 study in psoriatic arthritis, the planned phase 3 program in axial spondyloarthritis, and the potential for izokibep in multiple other indications for the benefit of patients globally.”

Key data to be presented at ACR Convergence 2022

Featured Oral Presentation

“Achievement of Different Treatment Targets with Izokibep Demonstrates Efficacy Benefits in Patients with Active Psoriatic Arthritis: Results from a 16-Week Randomized, Placebo-Controlled Phase 2 Clinical Trial” to be presented on November 13, 2022.

For more information on this study and oral presentation, please visit the ACR Convergence 2022 website here and reference Abstract 1597.

Poster Presentations

“Izokibep, a Novel IL-17A Inhibitor, Improves Patient-reported Outcomes – 16 Week Results from a Placebo-controlled Phase 2 Study in Patients with Active Psoriatic Arthritis” - this presentation has been recorded and posted to the ACR website by Peter Taylor, M.D., Ph.D., FRCP, Norman Collison Professor of Musculoskeletal Sciences at the University of Oxford and Director of Clinical Sciences at the Botnar Research Centre within the Nuffield Department of Orthopedics, Rheumatology and Musculoskeletal Sciences and chairs the NOCRI Translational Research Partnership. This presentation is part of the selected “Ignite” posters and will be on tour November 12, 2022.

For more information on this study and poster presentation, please visit the ACR Convergence 2022 website here and reference Abstract 0199.

“Izokibep Demonstrates Clinically Relevant Efficacy Benefits on Enthesitis, Dactylitis and Nail Outcomes in Active PsA Patients: A 16-Week Randomized, Placebo-controlled Trial” - this presentation has been recorded and posted to the ACR website by Kurt de Vlam, M.D., Ph.D., Professor, Division of Rheumatology, University Hospitals Leuven, Belgium. This presentation is part of the selected “Ignite” posters and will be on tour November 14, 2022.

For more information on this study and poster presentation, please visit the ACR Convergence 2022 website here and reference Abstract 2151.

Enthesitis KOL Event and Exhibit Booth information

In addition, the Company is hosting an affiliate event, “Enthesitis: The Patient Journey in PsA and AxSpA,” which is bringing together world-leading rheumatologists and patients to discuss the debilitating effects of enthesitis. This event will highlight the patient need for better treatment options to reduce the suffering associated with psoriatic arthritis and axial spondylarthritis. A replay will be available on the ACELYRIN website at www.acelyrin.com following the close of the ACR Convergence 2022 meeting.

ACELYRIN will also host an Exhibit Booth (#1054), where the Company’s clinical and executive leadership teams will be available for discussion throughout the meeting’s Exhibit hours.

About Izokibep

More than 300 patients – many for up to three years – have received izokibep, a small therapeutic protein inhibitor of interleukin-17A (IL-17A) designed to overcome the limitations of monoclonal antibodies. With high 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. The small size of izokibep – about one tenth the size of a monoclonal antibody – enables its potential to reach targeted tissues that may otherwise be inaccessible to the much larger monoclonal antibodies.

About ACELYRIN

ACELYRIN, INC. is a Los Angeles area-based 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 development and commercialization of promising drug candidates and leveraging its expertise to rapidly advance these medicines to patients. Under an exclusive licensing arrangement with Affibody AB, ACELYRIN holds global development and commercialization rights to izokibep, including in the United States, European Union, and Japan (excluding select Asian countries). For more information, please visit www.acelyrin.com

Forward Looking Statements

This press release may contain forward-looking statements. While ACELYRIN, INC. considers any projections to be based on reasonable assumptions, these forward- looking statements may be called into question by numerous hazards and uncertainties, so that actual results may differ materially from those anticipated in such forward-looking statements.

CONTACTS:

ACELYRIN, INC.
Tyler Marciniak
Investor Relations & Communications
tyler.marciniak@acelyrin.com
Mobile: +1 917 650 1523
Office: +1 805 730 0540