aTyr Pharma Announces Topline Results from Phase 3 EFZO-FIT™ Study of Efzofitimod in Pulmonary Sarcoidosis
aTyr Pharma, Inc. (Nasdaq: ATYR), a clinical stage biotechnology company, announced topline results from the Phase 3 EFZO-FIT™ study of efzofitimod in 268 patients with pulmonary sarcoidosis. The company plans to engage with the U.S. Food and Drug Administration (FDA) to review the results and determine the path forward for efzofitimod.
Key Findings from the EFZO-FIT™ Study
The EFZO-FIT™ study evaluated the efficacy and safety of efzofitimod at 3.0 mg/kg and 5.0 mg/kg doses versus placebo after 48 weeks of treatment. The study included a protocol-guided steroid taper in the first 12 weeks, followed by continued taper or rescue until week 48. While the primary endpoint was not met, the study demonstrated a clinical improvement in the King’s Sarcoidosis Questionnaire (KSQ)-Lung score at week 48 for 5.0 mg/kg efzofitimod compared to placebo (p=0.0479).
- A responder analysis of patients who achieved complete steroid withdrawal at week 48 with an improved KSQ-Lung score also showed improvement in patients treated with 5.0 mg/kg efzofitimod compared to placebo (p=0.0199).
- Lung function, as measured by forced vital capacity (FVC) at week 48, was maintained.
- The primary endpoint of change from baseline in mean daily oral corticosteroid (OCS) dose at week 48 was not met.
Study Outcomes and Statistical Significance
The study did not meet its primary endpoint. The change from baseline in mean daily OCS dose reduced to an average of 2.79 mg for 5.0 mg/kg efzofitimod vs 3.52 mg for placebo (p=0.3313). The study’s statistical analysis plan was designed on a hierarchical assessment basis, and as such, since the primary endpoint was not met, all subsequent statistical testing is reported as nominal findings. According to Sanjay S. Shukla, M.D., M.S., President and Chief Executive Officer of aTyr Pharma, “This study demonstrates that patients with chronic, symptomatic sarcoidosis can be managed with substantially lower steroid doses than previously thought."
Expert Perspectives
Daniel Culver, D.O., Chair of the Department of Pulmonary Medicine at the Cleveland Clinic and principal investigator of the trial, stated, “The results of EFZO-FIT™ demonstrate not only strong evidence of clinical efficacy for efzofitimod’s effect on quality of life and its capacity to facilitate steroid withdrawal, but also increased confidence that steroids overall can be reduced to manage symptoms and lung function without the fear of worsening disease.”
“The results of EFZO-FIT™ demonstrate not only strong evidence of clinical efficacy for efzofitimod’s effect on quality of life and its capacity to facilitate steroid withdrawal, but also increased confidence that steroids overall can be reduced to manage symptoms and lung function without the fear of worsening disease,” said Daniel Culver, D.O.
Study Outcome Measures at Week 48
| Endpoint | Results |
|---|---|
| Steroid Reduction Primary Endpoint | Change from baseline in mean daily OCS dose to an average of 2.79 mg for 5.0 mg/kg efzofitimod vs 3.52 mg for placebo (p=0.3313). Complete steroid withdrawal achieved for 52.6% of patients treated with 5.0 mg/kg efzofitimod vs 40.2% on placebo (p=0.0919) |
| KSQ-Lung Score | Change from baseline in KSQ-Lung score of 10.36 for 5.0 mg/kg efzofitimod vs 6.19 for placebo (p=0.0479). Proportion of patients who achieved complete steroid withdrawal with stable KSQ-Lung score was 46.9% of patients on 5.0 mg/kg of efzofitimod vs 35.7% on placebo (p=0.1241). Proportion of patients who achieved complete steroid withdrawal with KSQ-Lung improvement was 29.5% of patients on 5.0 mg/kg efzofitimod vs 14.4% in placebo (p=0.0199) |
| FVC | Change from baseline in absolute percent predicted FVC of -1.81 for patients in the 5.0 mg/kg efzofitimod vs -2.11 in placebo (p=0.7875) |
| Safety and Tolerability | Generally well-tolerated at both the 3.0 mg/kg and 5.0 mg/kg doses, consistent with a previously observed safety profile in all trials conducted to date |
Upcoming Presentation and Conference Call
aTyr Pharma plans to present the EFZO-FIT™ topline results at the upcoming European Respiratory Society Congress on Tuesday, September 30, 2025, in Amsterdam, Netherlands. A conference call and webcast will be held today, September 15, to discuss the results.
About Pulmonary Sarcoidosis
Pulmonary sarcoidosis is an inflammatory disease characterized by the formulation of granulomas, clumps of inflammatory cells, in one or more organs of the body. Current treatment options include corticosteroids and other immunosuppressive therapies, which have limited efficacy and are associated with serious side-effects.
About Efzofitimod
Efzofitimod is a first-in-class biologic immunomodulator in clinical development for the treatment of interstitial lung disease (ILD). It selectively modulates activated myeloid cells through neuropilin-2 to resolve inflammation without immune suppression.
About aTyr Pharma
aTyr Pharma is a clinical stage biotechnology company leveraging evolutionary intelligence to translate tRNA synthetase biology into new therapies for fibrosis and inflammation. The company’s lead therapeutic candidate is efzofitimod.
