ATyr Pharma's Lung Disease Treatment Trial Misses Endpoint, Shares Plummet 82%

aTyr Pharma's shares fell 82% after its Phase 3 trial of efzofitimod for treating lung disease missed its primary endpoint. Efzofitimod is a biologic immunomodulator in clinical development for interstitial lung disease. The drug selectively modulates activated myeloid cells to resolve aberrant inflammation and prevent fibrosis progression.

aTyr Pharma, Inc. (Nasdaq: ATYR) faced a significant setback today as its Phase 3 EFZO-FIT™ trial of efzofitimod in pulmonary sarcoidosis missed its primary endpoint. The trial, which enrolled 268 patients, did not meet its target of reducing mean daily oral corticosteroid dose at week 48, with a reduction to 2.79 mg for efzofitimod versus 3.52 mg for placebo (p=0.3313) Atyr Pharma Announces Topline Results from Phase 3 Efzo-Fit?? Study of Efzofitimod in Pulmonary Sarcoidosis^[1]aTyr Pharma Announces Topline Results from Phase 3 EFZO-FIT™ Study of Efzofitimod in Pulmonary Sarcoidosis^[2].

Despite the primary endpoint failure, the trial did show some promising secondary outcomes. Notably, 52.6% of patients on efzofitimod achieved complete steroid withdrawal compared to 40.2% on placebo (p=0.0919), and 29.5% of efzofitimod patients achieved both steroid withdrawal and lung score improvement compared to 14.4% for placebo (p=0.0199) aTyr Pharma Announces Topline Results from Phase 3 EFZO-FIT™ Study of Efzofitimod in Pulmonary Sarcoidosis^[2].

The drug was well-tolerated, with a consistent safety profile. However, the higher than anticipated placebo response (40.2% of placebo patients achieved complete steroid withdrawal) likely contributed to the trial's failure. This suggests either a strong placebo effect in sarcoidosis treatment or potential issues with the trial design and endpoints selected aTyr Pharma Announces Topline Results from Phase 3 EFZO-FIT™ Study of Efzofitimod in Pulmonary Sarcoidosis^[2].

aTyr Pharma plans to engage with the U.S. Food and Drug Administration (FDA) to determine the path forward for efzofitimod in pulmonary sarcoidosis. The company's shares fell 82% after the announcement, highlighting the significant commercial challenge this result presents .