8-K: ACELYRIN Announces Positive Clinical Trial Results for Izokibep in Psoriatic Arthritis and Hidradenitis Suppurativa

ACELYRIN, INC. reported positive top-line results from its Phase 2b/3 clinical trial of izokibep in psoriatic arthritis and long-term data from its Phase 2b trial in hidradenitis suppurativa, demonstrating sustained responses and deepening clinical benefit.

Summary

• ACELYRIN, INC. announced positive results from a Phase 2b/3 trial of izokibep for psoriatic arthritis (PsA), meeting the primary endpoint of ACR50 at 16 weeks with high statistical significance.
• The 160 mg weekly (QW) and every other week (Q2W) doses showed improved responses on higher hurdle endpoints like ACR70, PASI100, and Minimal Disease Activity compared to the Phase 2 80 mg Q2W dose.
• The PsA trial had a low discontinuation rate of less than 3%, with mild injection site reactions being the most common adverse event.
• Long-term data from a Phase 2b trial of izokibep in hidradenitis suppurativa (HS) showed sustained responses and deepening clinical benefit through 32 weeks.
• Approximately one-third of HS patients achieved HiSCR100, or resolution of abscesses and nodules, by week 16 and through week 32.
• Patients who switched from placebo to izokibep at week 16 achieved similar responses to those who started on izokibep at baseline.
• The company plans to remediate certain findings in the PsA trial to enable it as the first of two registrational trials in PsA.
• A Phase 3 trial in HS is ongoing, with topline data expected by the end of 2024, and a confirmatory Phase 3 trial of approximately 400 patients is planned.

Sentiment

Score: 8

Explanation: The document presents very positive clinical trial results for izokibep, with strong efficacy and a favorable safety profile. The company is moving forward with its development program, which is likely to be viewed positively by investors. However, there are some risks and challenges, such as the need to remediate the PsA trial and the transition of services from Fortrea.

Positives

• Izokibep demonstrated statistically significant efficacy in treating psoriatic arthritis, meeting the primary endpoint of ACR50 at 16 weeks.
• The drug showed strong results in achieving higher hurdle endpoints like ACR70, PASI100, and Minimal Disease Activity in PsA.
• Izokibep has a favorable safety profile, consistent with the IL-17A class, with low discontinuation rates in both PsA and HS trials.
• Long-term data in HS showed sustained responses and deepening clinical benefit, with a significant portion of patients achieving HiSCR100.
• The drug's small size and high potency may offer differentiated clinical benefits for patients.
• The company is moving forward with izokibep clinical development program after addressing a dose-sequencing error.
• The company is planning a confirmatory phase 3 trial of approximately 400 patients to address FDA guidance.

Negatives

• A vendor programming error caused a dose-sequencing error in the 160 mg every other week (Q2W) and 80mg every four weeks (Q4W) dosing arms of the Phase 2b/3 trial in Psoriatic Arthritis.
• The company had to conduct an independent audit of the PsA and HS trials due to the dose-sequencing error.
• The company plans to remediate certain findings in the PsA trial to enable it as the first of two registrational trials.
• The primary endpoint of the HS study did not meet statistical significance, although long term data was positive.

Risks

• The company needs to remediate certain findings in the PsA trial, which could delay the registrational process.
• The transition of services from Fortrea could pose challenges and impact ongoing studies.
• The company is subject to risks and uncertainties associated with the successful completion of development and regulatory activities.
• There is a risk that future clinical trial results could differ adversely from prior results.
• The company faces competitive risks and market volatility.

Future Outlook

The company anticipates topline data from an ongoing Phase 3 trial in HS by the end of 2024 and plans to initiate an additional Phase 3 program in axial spondyloarthritis (AxSpA). They also plan a confirmatory phase 3 trial of approximately 400 patients for HS.

Management Comments

• Philip Mease, MD, MACR, stated that the positive Phase 2b/3 data reinforces the potential for izokibep to provide meaningful benefit in treating psoriatic arthritis.
• Shao-Lee Lin, MD, PhD, Founder and CEO of ACELYRIN, expressed excitement about the continued progress with izokibep in both PsA and HS.
• Shao-Lee Lin, MD, PhD, noted that the 160 mg Q2W dose delivers higher clinical responses than those reported by the approved IL-17A agents.
• Kim Papp MD, PhD, stated that the magnitude and depth of responses for signs and symptoms of Hidradenitis Suppurativa in this long-term study are consistent with izokibeps mechanism of action.
• Falk Bechara MD, noted that the data is impressive, showing izokibep dose ordered, fast speed of onset across endpoints.

Industry Context

These results position ACELYRIN as a potential competitor in the immunology space, particularly in the treatment of psoriatic arthritis and hidradenitis suppurativa, where there is a need for more effective therapies. The company is aiming to differentiate itself from existing IL-17A and IL-17A&F agents by demonstrating higher efficacy and a favorable safety profile.

Comparison to Industry Standards

• The document compares izokibep's results to those of approved IL-17A agents and IL-17A&F agents, suggesting that izokibep may offer higher clinical responses without the associated safety liabilities.
• In PsA, izokibep's ACR50/PASI100 composite responses are compared to Bimekizumab and Sonelokimab, indicating comparable or better results.
• In HS, izokibep's HiSCR100 achievement is compared to Bimekizumab and Secukinumab, suggesting a more rapid and robust response.
• The document notes that izokibep demonstrated resolution despite the highest burden of enthesitis, an effect not previously reported by other agents such as Secukinumab.

Stakeholder Impact

• Shareholders are likely to react positively to the strong clinical trial results and the potential for izokibep to become a successful product.
• Patients with psoriatic arthritis and hidradenitis suppurativa may benefit from a new treatment option with potentially higher efficacy and a favorable safety profile.
• Employees of ACELYRIN are likely to be motivated by the positive progress of the company's clinical programs.
• The transition of services from Fortrea may impact suppliers and other partners.

Next Steps

• The company plans to remediate certain findings in the PsA trial to enable it as the first of two registrational trials.
• The company will work with Fortrea on certain ongoing studies while transitioning other services.
• Topline data from an ongoing Phase 3 trial in HS is expected by the end of 2024.
• A confirmatory Phase 3 trial of approximately 400 patients is planned for HS.
• The company plans to initiate an additional Phase 3 program in axial spondyloarthritis (AxSpA).
• Further data from these trials will be presented at future scientific meetings.

Key Dates

Keywords

izokibep, psoriatic arthritis, hidradenitis suppurativa, clinical trial, ACR50, HiSCR100, IL-17A, Phase 2b/3, Phase 2b, immunology