Efzofitimod shows clinical benefit, but fails to meet primary endpoint in pulmonary sarcoidosis study.

A clinical study of efzofitimod in pulmonary sarcoidosis did not meet its primary endpoint, but showed clinical benefits across multiple study parameters. 52.6% of patients treated with 5.0 mg/kg efzofitimod achieved complete steroid withdrawal at week 48, compared to 40.2% on placebo. Efzofitimod was well-tolerated, and the company plans to engage with the FDA to determine its path forward.

aTyr Pharma, Inc. (Nasdaq: ATYR) announced topline results from its Phase 3 EFZO-FIT™ study of efzofitimod in 268 patients with pulmonary sarcoidosis. While the study did not meet its primary endpoint of reducing oral corticosteroid (OCS) dose, it demonstrated significant clinical benefits across multiple parameters.

Efzofitimod, a first-in-class biologic immunomodulator, showed a 52.6% complete steroid withdrawal rate at week 48 compared to 40.2% on placebo (p=0.0919). Additionally, the treatment group exhibited clinical improvement in the King’s Sarcoidosis Questionnaire (KSQ)-Lung score at week 48 (p=0.0479). A greater proportion of patients achieved complete steroid withdrawal with KSQ-Lung score improvement in the efzofitimod group (29.5%) compared to placebo (14.4%) (p=0.0199). Lung function, as measured by forced vital capacity (FVC), was maintained in both groups.

Efzofitimod was well-tolerated, with a consistent safety profile observed at both 3.0 mg/kg and 5.0 mg/kg doses. The company plans to engage with the U.S. Food and Drug Administration (FDA) to determine the path forward for efzofitimod in pulmonary sarcoidosis.

The study was a global Phase 3 interventional trial comparing efzofitimod at 3.0 mg/kg and 5.0 mg/kg doses versus placebo over 48 weeks. Despite the primary endpoint not being met, the study demonstrated improvements in clinically relevant endpoints, suggesting potential benefits for patients with pulmonary sarcoidosis.

aTyr Pharma will present the EFZO-FIT™ topline results at the upcoming European Respiratory Society Congress on September 30, 2025. The company will also host a conference call and webcast on September 15, 2025, to discuss the results.