On September 15, 2025, shares of aTyr Pharma dropped 83% following the failure of its Phase 3 efzofitimod trial. This significant decline highlights concerns about the future of the company's lead treatment for interstitial lung diseases.
EFZO-FIT Trial Falls Short
The EFZO-FIT trial, which enrolled 268 patients with pulmonary sarcoidosis, failed to demonstrate a statistically significant reduction in oral corticosteroid use compared to placebo. Patients receiving 5.0 mg/kg efzofitimod showed an average reduction in daily steroid dose to 2.79 mg versus 3.52 mg for placebo, with a p-value of 0.3313 that fell well short of statistical significance.
Clinical Data and Investor Reactions
Despite missing the primary endpoint, aTyr highlighted several encouraging secondary findings. 52.6% of patients in the 5.0 mg/kg efzofitimod group achieved complete steroid withdrawal at week 48 compared to 40.2% in the placebo group. Patients treated with efzofitimod also showed improved quality of life scores on the King's Sarcoidosis Questionnaire-Lung assessment. These results, however, did not prevent a massive sell-off, wiping out approximately $500 million in market capitalization.
Market Outlook for aTyr Pharma
As of 10:11 AM EDT, aTyr shares were trading at $1.0201, down 83.08% from the previous close. This dramatic decline represents one of the most significant reductions in the company's trading history. Analyst price targets for aTyr range from $9.50 to $35.00, but significant downward revisions are expected following the trial results.
Despite the setback with its clinical trial, aTyr Pharma continues to explore potential regulatory pathways and development options for efzofitimod. The company's future will depend on its ability to navigate these challenges and find new avenues for treating pulmonary sarcoidosis.
