aTyr Pharma Reports Positive Topline Results from Phase 3 Efzofitimod Sarcoidosis Trial

aTyr Pharma, Inc. a clinical-stage biotech company developing first-in-class therapeutics from its proprietary tRNA synthetase platform, today announced topline results from its Phase 3 EFZO-FIT trial evaluating efzofitimod in 268 patients with pulmonary sarcoidosis.

The study did not meet its primary endpoint, which measured the change in mean daily oral corticosteroid (OCS) dose at 48 weeks. Patients receiving the higher 5.0 mg/kg dose of efzofitimod showed a steroid dose reduction of 2.79 mg compared to 3.52 mg with placebo (p=0.3313). Due to the hierarchical statistical design of the trial, all subsequent endpoints are considered exploratory, or “nominal.”

Despite this, the study showed promising clinical signals. Notably, patients receiving 5.0 mg/kg efzofitimod demonstrated a statistically significant improvement in the King’s Sarcoidosis Questionnaire (KSQ)-Lung score at week 48 (p=0.0479), a validated measure of quality of life in sarcoidosis. Additionally, a responder analysis revealed that patients who achieved complete steroid withdrawal and improved KSQ-Lung scores were more likely to have received efzofitimod (p=0.0199). Lung function, as measured by forced vital capacity (FVC), was maintained across groups.

“These consistent findings suggest efzofitimod may positively impact quality of life and preserve lung function while reducing steroid burden,” said Dr. Sanjay S. Shukla, President and CEO of aTyr Pharma. “We believe these results show meaningful drug activity, and we look forward to engaging with the FDA to determine the next steps.”

Pulmonary sarcoidosis is a serious form of interstitial lung disease with no approved steroid-sparing therapies. Current treatment relies heavily on long-term corticosteroid use, which carries significant side effects.

Dr. Daniel Culver, Chair of Pulmonary Medicine at the Cleveland Clinic and principal investigator of the trial, called the study “an important step forward for the field,” highlighting that it is the largest interventional trial in sarcoidosis to date. He noted that the data provide valuable insights for future treatment strategies, particularly regarding safe steroid tapering.

The EFZO-FIT trial included patients receiving either 3.0 mg/kg or 5.0 mg/kg doses of efzofitimod versus placebo over 48 weeks, with a structured corticosteroid tapering phase in the first 12 weeks. While the trial did not meet its primary endpoint, aTyr plans to present the full dataset to the U.S. Food and Drug Administration (FDA) to evaluate potential regulatory paths forward.

aTyr expressed gratitude to trial participants, investigators, advocacy groups, and partner Kyorin Pharmaceutical for their contributions to the study.