aTyr Pharma, Inc.'s (ATYR) Failed Drug Trial Spurs Securities Lawsuit -- Hagens Berman

SAN FRANCISCO, Oct. 9, 2025 /PRNewswire/ -- A federal class-action lawsuit has been filed against aTyr Pharma, Inc. (NASDAQ: ATYR) following a devastating 83% drop in the biotech company's stock price after its lead drug candidate failed to meet its primary endpoint in a critical Phase 3 trial.

Prominent shareholders rights firm Hagens Berman has been investigating the alleged claims.

Blog: www.hbsslaw.com/blog

The firm urges investors in aTyr who suffered significant losses to submit your losses now. The firm also encourages persons with knowledge who may be able to assist in the investigation to contact its attorneys.

Class Period: Jan. 16, 2025 – Sep. 12, 2025
Lead Plaintiff Deadline: Dec. 8, 2025
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aTyr Pharma, Inc. (AYTR) Securities Litigation:

The suit, Munguia v. aTyr Pharma Inc., filed in the U.S. District Court for the Southern District of California, alleges that aTyr and its top executives made false and misleading statements about the efficacy of its drug, Efzofitimod, leading investors to purchase stock at artificially inflated prices.

The proposed class covers all investors who acquired aTyr common stock between January 16, 2025, and September 12, 2025, inclusive.

At the heart of the allegations is aTyr's Phase 3, randomized, double-blind, placebo-controlled study, known as EFZO-FIT, which evaluated intravenous Efzofitimod in patients with pulmonary sarcoidosis. The drug was intended to help patients reduce their dependency on steroids.

According to the complaint, throughout the Class Period, aTyr executives expressed overwhelmingly positive statements and confidence in the study's design, particularly its forced taper approach intended to gauge the drug's ability to allow patients to completely wean themselves off steroids.

However, the lawsuit claims that concurrently with these optimistic pronouncements, the company was allegedly concealing material adverse facts concerning Efzofitimod's capability to allow a patient to completely taper their steroid usage—a key measure of efficacy. The lawsuit asserts that aTyr's statements crossed the line into securities law violations by allegedly misrepresenting the drug's true prospects.

The truth, as alleged in the complaint, came to light on Monday, September 15, 2025. Pre-market, aTyr hosted an investor call announcing that the EFZO-FIT study did not meet its primary endpoint: the change from baseline in mean daily oral corticosteroid (OSC) dose at week 48.

The disappointing topline results prompted a swift and brutal market reaction. aTyr's common stock, which had closed at $6.03 per share on the preceding Friday, September 12, cratered to close at just $1.02 per share on September 15—a catastrophic one-day decline of 83.2%.

In its post-announcement comments, the company stated that it would engage with the Food and Drug Administration (FDA) to determine a path forward, acknowledging the setback.

Hagens Berman's Investigation

Hagens Berman is investigating whether aTyr may have misled investors about its data and trial design while emphasizing Efzofitimod's multi-billion-dollar market opportunity. "We're scrutinizing whether aTyr's previous representations about the drug's efficacy were materially misleading to investors," said Reed Kathrein, the Hagens Berman partner leading the firm's investigation.

If you invested in aTyr and have substantial losses, or have knowledge that may assist the firm's investigation, submit your losses now »

If you'd like more information and answers to frequently asked questions about the aTyr case and our investigation, read more »

Whistleblowers: Persons with non-public information regarding aTyr should consider their options to help in the investigation or take advantage of the SEC Whistleblower program. Under the new program, whistleblowers who provide original information may receive rewards totaling up to 30 percent of any successful recovery made by the SEC. For more information, call Reed Kathrein at 844-916-0895 or email [email protected].

About Hagens Berman
Hagens Berman is a global plaintiffs' rights complex litigation firm focusing on corporate accountability. The firm is home to a robust practice and represents investors as well as whistleblowers, workers, consumers and others in cases achieving real results for those harmed by corporate negligence and other wrongdoings. Hagens Berman's team has secured more than $2.9 billion in this area of law. More about the firm and its successes can be found at hbsslaw.com. Follow the firm for updates and news at @ClassActionLaw.

SOURCE Hagens Berman Sobol Shapiro LLP