aTyr Pharma Stock Drops 83% After Failed Drug Trial, Lawsuit Filed

aTyr Pharma's lead drug candidate, Efzofitimod, failed to meet its primary endpoint in a Phase 3 trial, leading to an 83% drop in the biotech company's stock price. A federal class-action lawsuit has been filed against aTyr, alleging that executives made false and misleading statements about the drug's efficacy. The lawsuit seeks to represent investors who purchased aTyr common stock between January 16 and September 12, 2025. The firm urges investors to submit their losses and encourages persons with knowledge to contact their attorneys.

aTyr Pharma, Inc. (NASDAQ: ATYR) has been the subject of intense scrutiny following the failure of its lead drug candidate, Efzofitimod, to meet its primary endpoint in a Phase 3 trial. The drug was intended to help patients with pulmonary sarcoidosis reduce their dependency on steroids. The disappointing results led to an 83% drop in the company's stock price on September 15, 2025, sending shares from $6.03 to $1.02.

The market reaction was swift and brutal, prompting a federal class-action lawsuit against aTyr. The lawsuit, Munguia v. aTyr Pharma Inc., alleges that the company and its executives made false and misleading statements about the efficacy of Efzofitimod. The suit claims that aTyr's statements about the drug's capabilities were materially misleading, leading investors to purchase stock at artificially inflated prices, according to a Hagens Berman filing.

Prominent shareholders rights firm Hagens Berman has been investigating the allegations. The firm is urging investors in aTyr who suffered significant losses to submit their losses now. The firm also encourages persons with knowledge who may be able to assist in the investigation to contact its attorneys, according to a Hagens Berman statement.

The investigation focuses on whether aTyr may have misled investors about the quality of its Phase 2 efzofitimod data and its Phase 3 EFZO-FIT trial design. aTyr assured investors that the Phase 2 data was some of the best ever seen and that efzofitimod could own the multi-billion-dollar market opportunity for treating interstitial lung diseases. However, the Phase 3 trial results did not meet the primary endpoint, with the placebo group outperforming even the company's most aggressive modeling, according to that statement.

The lawsuit seeks to represent all investors who acquired aTyr common stock between January 16, 2025, and September 12, 2025. The lead plaintiff deadline for the class action is December 8, 2025, as noted in the Hagens Berman filing.

Hagens Berman's investigation is ongoing, and the firm is encouraging whistleblowers with non-public information regarding aTyr to consider their options to assist in the investigation or take advantage of the SEC Whistleblower program, which can offer rewards up to 30% of any successful recovery made by the SEC, the statement adds.