aTyr Pharma Shares Plummet After Lung Disease Drug Flop

BOSTON, Sept. 15, 2025 - aTyr Pharma’s stock tumbled to a record low today after its experimental treatment for pulmonary sarcoidosis failed to meet its primary endpoint in a late-stage trial, sending shares down more than 80%.

Nut Graf: The biotech’s only clinical-stage asset, efzofitimod, aimed to reduce steroid dependence in patients with a chronic inflammatory lung condition. Its inability to demonstrate a statistically significant steroid-sparing effect triggered a collapse in market value, underscoring the high stakes of late-phase failures in small-cap biotech.

Key Details

  • Trial outcome: 5 mg/kg efzofitimod group cut average daily corticosteroid dose to 2.79 mg versus 3.52 mg with placebo (p=0.3313), missing the study’s primary objective.
  • Stock reaction: Shares plunged over 80%, trading near $1.20 by midday, compared with pre-market levels above $6.
  • Company response: aTyr plans to engage the FDA to review the data, highlighting nominal improvements in quality-of-life measures and steroid withdrawal rates.

Efzofitimod Study Findings

  • Participants: 268 patients with moderate-to-severe pulmonary sarcoidosis.
  • Efficacy signals:
    • Complete steroid withdrawal achieved in 52.6% of treated patients versus 40.2% on placebo (p=0.0919).
    • Improvement in King’s Sarcoidosis Questionnaire-Lung score reached nominal significance (p=0.0479).
  • Safety: The drug’s tolerability profile aligned with previous studies.

Market Impact and Outlook

  • aTyr’s market capitalization now approximates its cash reserves, raising concerns about the company’s runway absent a redemption event.
  • Analysts at Leerink Partners and Cantor Fitzgerald downgraded their ratings, citing an “unusually high placebo response” and uncertain regulatory path.
  • Upcoming: Detailed trial results to be presented at the European Respiratory Society Congress on Sept. 30, 2025, followed by FDA discussions.

Background on Pulmonary Sarcoidosis

Pulmonary sarcoidosis is characterized by granulomatous inflammation in the lungs and lymph nodes, often managed with prolonged corticosteroid therapy that carries significant side effects. Efzofitimod represented a novel immunomodulatory approach targeting steroid reduction without compromising disease control.

-END-