Larimar Therapeutics Faces Securities Investigation After Anaphylaxis Safety Signal Emerges in Nomlabofusp Trials for Friedreich's Ataxia
Key Insights
Pomerantz LLP (search) is investigating Larimar Therapeutics for potential securities fraud related to nomlabofusp, a subcutaneously injected treatment for Friedreich's ataxia (search).
On June 29, 2026, Larimar disclosed that anaphylaxis occurred in 10 of 43 patients in its ongoing open-label study, triggering a 12.57% stock decline.
The company submitted the first section of a rolling Biologics License Application seeking accelerated approval despite the ongoing safety signal.
Pomerantz LLP (search) has launched an investigation into Larimar Therapeutics, Inc. (NASDAQ: LRMR) over concerns that the company and certain officers and/or directors may have engaged in securities fraud or other unlawful business practices. The investigation centers on disclosures surrounding nomlabofusp, an investigational therapy administered via daily subcutaneous injections for the treatment of Friedreich's ataxia (search).
The law firm, which maintains offices in New York, Chicago, Los Angeles, London, Paris, and Tel Aviv, is examining whether Larimar made misleading statements or failed to adequately disclose material safety risks associated with its lead candidate. Investors who purchased Larimar securities are advised to contact Danielle Peyton at newaction@pomlaw.com or 646-581-9980, extension 7980.
Safety Signal Emerges in Open-Label Extension Study
The investigation follows two significant disclosures that rattled investor confidence. On September 29, 2025, Larimar issued a press release announcing data from an ongoing long-term open-label study evaluating nomlabofusp. While the company characterized the data as "positive," the release disclosed that anaphylaxis or a severe allergic reaction was reported in seven participants. The market reacted swiftly: Larimar's stock price fell $1.72 per share, or 33.66%, closing at $3.38 per share on the same day.
Then, on June 29, 2026, Larimar released new data from the same ongoing open-label study and confirmed the submission of the first section of its rolling Biologics License Application (BLA) seeking accelerated approval for nomlabofusp as a treatment for Friedreich's ataxia (search). Although the press release again characterized the data as "positive," it revealed an ongoing safety signal, with anaphylaxis now reported in 10 of 43 patients. On this news, Larimar's stock price fell an additional $0.46 per share, or 12.57%, closing at $3.20 per share on June 29, 2026.
Regulatory Path and Clinical Context
Friedreich's ataxia (search) is a rare, inherited neurodegenerative disorder characterized by progressive damage to the nervous system. The submission of a rolling BLA represents a significant regulatory step, allowing Larimar to submit completed sections of the application to the U.S. Food and Drug Administration for review on an ongoing basis, rather than waiting for all components to be finalized. The company is pursuing accelerated approval, a pathway designed to expedite the availability of therapies for serious conditions that address unmet medical needs.
However, the emergence of anaphylaxis—a severe, potentially life-threatening allergic reaction—in a growing proportion of trial participants raises critical questions about the benefit-risk profile of nomlabofusp. The increase from seven affected participants in September 2025 to 10 of 43 patients by June 2026 suggests that the safety signal has persisted and may be dose- or exposure-related.
Securities Investigation Underway
Pomerantz LLP (search), founded by the late Abraham L. Pomerantz—widely regarded as the dean of the class action bar—has specialized in securities class action litigation for over 85 years. The firm has recovered numerous multimillion-dollar damages awards on behalf of class members. The current investigation seeks to determine whether Larimar and its leadership adequately disclosed the nature and severity of the anaphylaxis risk to investors, or whether the company's characterization of trial data as "positive" constituted a misleading portrayal of nomlabofusp's safety profile.
The investigation remains ongoing, and no formal charges have been filed as of the date of the announcement. Investors with relevant information are encouraged to contact the firm.