ACELYRIN Announces Phase 2b/3 Trial of Izokibep Did Not Meet Primary Endpoint

ACELYRIN has announced that the Phase 2b/3 clinical trial evaluating izokibep for non-infectious, non-anterior uveitis did not achieve its primary endpoint. The trial results did not demonstrate a statistically significant improvement in time to treatment failure versus placebo. Consequently, the company has decided to cease further internal investment in the development of izokibep for this indication.

Phase 2b/3 Clinical Trial Overview and Results

The Phase 2b/3 trial (NCT05683496) aimed to evaluate the efficacy of izokibep in patients with non-infectious, non-anterior uveitis. Participants were randomized in a 1:1 ratio to receive weekly subcutaneous injections of either izokibep 160 mg or placebo. The study's primary endpoint was the improvement in time to treatment failure, measured by treatment failure rates at 24 weeks.

Topline Results

       • Treatment Failure Rates at 24 Weeks:

               - Izokibep: 45.0%

               - Placebo: 50.7%

               - P-value: 0.4914

The trial failed to achieve statistical significance for the primary endpoint, and no clinical benefit was observed. Secondary endpoints also did not demonstrate statistical significance. However, izokibep was well-tolerated, with a safety profile consistent with earlier studies and its IL-17A class.

ACELYRIN’s Strategic Shift

In light of these results and previously announced pipeline guidance, ACELYRIN has opted not to pursue further internal investment in izokibep’s development.

Mina Kim, Chief Executive Officer of ACELYRIN, expressed gratitude to all stakeholders involved in the trial:

“We are very grateful to all the patients, families, and clinical investigators for their time and effort put into this trial, and, like them, we are disappointed that it did not meet its primary endpoint. Consistent with our previously announced pipeline prioritization strategy, we will continue to focus on advancing subcutaneous lonigutamab for patients with thyroid eye disease. We look forward to hosting a lonigutamab investor event in early 2025 and remain on track to initiate the Phase 3 program in the first quarter of 2025. Given our strong balance sheet, we will also continue evaluating selective and opportunistic pipeline expansion opportunities.”

Future Focus: Lonigutamab for Thyroid Eye Disease

ACELYRIN is redirecting its focus to the development of subcutaneous lonigutamab for thyroid eye disease (TED). The company plans to initiate a Phase 3 program for lonigutamab in Q1 2025 and will host an investor event early next year to discuss this promising pipeline candidate.

Conclusion

While the izokibep trial results are disappointing, ACELYRIN remains committed to its strategic priorities. With a robust financial position, the company will focus on advancing its most promising assets and exploring new opportunities to expand its pipeline.