aTyr Pharma (ATYR) Stock Jumps 5% On FDA Green Light

TLDR

• aTyr Pharma reached agreement with the FDA on the protocol for a Phase 3 trial of efzofitimod in pulmonary sarcoidosis.
• The trial will start activities in the fourth quarter of 2026.
• ATYR stock rose 5% following the announcement.
• The study will enroll about 372 patients across a 54-week trial.
• The design is backed by earlier subgroup data from the Phase 3 EFZO-FIT study.

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aTyr Pharma (ATYR) stock climbed 5% on Wednesday after the company announced it had aligned with the U.S. Food and Drug Administration on the protocol for its upcoming Phase 3 trial. The trial will test efzofitimod in patients with chronic pulmonary sarcoidosis.

aTyr Pharma, Inc., ATYR

The San Diego based biotech said it plans to begin study-related activities in the fourth quarter of 2026. It will also focus on regulatory filings in both the U.S. and Europe as the trial gets underway.

Pulmonary sarcoidosis is a form of interstitial lung disease. Patients with this condition often face limited treatment options, especially those who need long-term therapy.

What the Trial Will Look Like

The Phase 3 study will be global, randomized, double-blind and placebo-controlled. Researchers designed it to evaluate both the efficacy and safety of efzofitimod in patients with moderate to severe disease.

The trial will run for 54 weeks. Participants will be split into two equal groups, receiving either 5.0 mg/kg of efzofitimod or a placebo, delivered intravenously every three weeks for a total of 17 doses.

aTyr expects to enroll roughly 372 patients. Eligible participants must already be on a stable, low dose of oral corticosteroids or a background immunosuppressant, and that background treatment will stay steady throughout the study.

The primary endpoint is the change in forced vital capacity from baseline at week 48. A key secondary endpoint will track changes in the King’s Sarcoidosis Questionnaire-Lung score over the same period.

Backed by Earlier Trial Data

This trial design didn’t come out of nowhere. It’s built on a subgroup analysis from the earlier Phase 3 EFZO-FIT study.

That analysis focused on patients with restrictive lung disease, defined as having forced vital capacity at or below 80% of predicted with a normal FEV1/FVC ratio. Those patients showed a meaningful benefit in lung function when treated with the 5.0 mg/kg dose compared to placebo.

They also saw improvements across multiple patient-reported outcomes, including the KSQ-Lung score. aTyr presented these findings at the World Association of Sarcoidosis and Other Granulomatous Disorders 2026 Congress.

CEO Sanjay Shukla said the company received feedback from the FDA earlier in the week and called the alignment an important milestone. He pointed to the lack of treatment options for chronic sarcoidosis patients as a reason the drug could matter for the space.

Efzofitimod is a biologic immunomodulator. It works by targeting activated myeloid cells through neuropilin-2, aiming to resolve inflammation without broadly suppressing the immune system.

The drug is also being tested separately in a Phase 2 study for systemic sclerosis-related interstitial lung disease. That trial, called EFZO-CONNECT, is running alongside the sarcoidosis program.

aTyr noted that moving forward with the Phase 3 sarcoidosis trial will require additional capital. The company said it may pursue this through equity or debt offerings, grants, collaborations or licensing deals.

No specific funding timeline or dollar figure was given in the announcement.