Equillium’s pivotal GvHD study of anti-CD6 antibody comes up short
Equillium's Phase 3 EQUATOR Study of Itolizumab in Acute Graft-Versus-Host Disease Falls Short of Primary Endpoint
Key Findings
- Itolizumab failed to improve complete response (CR) or overall response rate (ORR) at Day 29 compared to placebo16
- Study achieved statistical significance in several longer-term secondary endpoints:
* - Median duration of CR:*
336 days vs 72 days (p=0.017)110
* - Median failure-free survival:*
154 days vs 70 days (p=0.043)10
* - CR at Day 99:*
44.9% vs 28.6% (p=0.035)10
- Positive trend in overall survival favoring itolizumab (24.4% vs 32.5% mortality)1
Implications
Despite missing the primary endpoint, Equillium is pursuing regulatory approval based on the longer-term benefits demonstrated1. The company has:
- Filed for Breakthrough Therapy designation
- Requested an FDA meeting to discuss potential for Accelerated Approval1
- Plans to submit a biologics license application in first half of 2026 if FDA feedback is positive1
Background
Itolizumab is a first-in-class anti-CD6 monoclonal antibody designed to modulate T cell activity in autoimmune and inflammatory diseases5. Acute graft-versus-host disease (aGVHD) is a serious complication of stem cell transplants with high mortality and no approved first-line therapies10.
Next Steps
Equillium expects FDA feedback in May 2025 regarding the potential regulatory path forward1. The company's ability to pursue approval will likely depend on the FDA's willingness to consider the longer-term benefits despite the missed primary endpoint.
Sources:
1. https://www.fiercebiotech.com/biotech/equillium-misses-primary-endpoint-plus-2-key-secondaries-still-plans-approval-filing
5. https://touchimmunology.com/insight/novel-anti-cd6-monoclonal-antibody-itolizumab-showcases-proof-of-concept-in-ulcerative-colitis/
6. https://www.bioworld.com/articles/718569-come-what-may-equillium-marches-on-with-itolizumab-in-gvhd
10. https://www.stocktitan.net/news/EQ/equillium-announces-results-of-the-phase-3-equator-study-of-a352nuw6v6dq.html