8-K: Larimar Therapeutics Refines Nomlabofusp BLA Timeline for Friedreich's Ataxia Following FDA Safety Database Recommendations

Larimar Therapeutics announced refined timelines for its nomlabofusp Biologics License Application submission for Friedreich's Ataxia to incorporate FDA-recommended safety data, now targeting Q2 2026 for accelerated approval.

Summary

• Larimar Therapeutics received written recommendations from the U.S. Food and Drug Administration (FDA) regarding the safety database for its nomlabofusp Biologics License Application (BLA) for Friedreich's Ataxia (FA).
• The FDA recommended evaluating safety in at least 30 participants with continuous exposure for 6 months, including a subset of at least 10 with 1 year of continuous exposure; the large majority of safety data should be from participants receiving the 50 mg dose.
• Based on these recommendations, the BLA submission seeking accelerated approval is now planned for the second quarter of 2026 to allow for the inclusion of the recommended safety data from adults and children.
• The FDA is open to the use of skin frataxin (FXN) concentrations as a reasonably likely surrogate endpoint (RLSE), acknowledging that submitted data appear to support a relationship between increased skin FXN and relevant tissues.
• Data from the Open Label Extension (OLE) study, including participants on the 50 mg dose, and adolescent pharmacokinetic (PK) run-in data are expected in September 2025.
• Nomlabofusp has shown increased skin FXN levels in the OLE study, with a mean increase to 72% of healthy volunteer levels at Day 90 from 16% at baseline.
• The company observed trends towards improvement in clinical outcomes (mFARS, FARS-ADL, Modified Fatigue Impact Scale, 9 Hole Peg Test) at Day 90 in the OLE study.
• Nomlabofusp has been generally well-tolerated in long-term treatment, with local injection site reactions being the most common adverse events, which are typically mild, brief, and self-limited, with no participant withdrawals due to these reactions.
• Anaphylaxis has been deemed an adverse drug reaction likely related to nomlabofusp by the Larimar Safety Team, with premedication recommended for participants with prior exposure who have been off treatment for some time.
• Larimar's participation in the FDA's Support for Clinical Trials Advancing Rare Disease Therapeutics (START) pilot program continues to expedite the development of nomlabofusp.
• Global Phase 3 study activities are ongoing with identification and qualification of sites in the U.S., Europe, U.K., Canada, and Australia; this study is intended as the confirmatory study for accelerated approval.
• The company reported $157.5 million in cash and investments as of March 31, 2025, with a projected cash runway into Q2 2026.
• A U.S. launch for nomlabofusp is planned for early 2027.

Sentiment

Score: 6

Explanation: The announcement provides crucial clarity from the FDA on the regulatory path for nomlabofusp, including acceptance of a surrogate endpoint and specific safety database requirements. While the BLA submission timeline has been extended to Q2 2026, this delay is for a defined purpose (inclusion of more safety data) and is accompanied by positive long-term OLE data and a solid cash runway. The identification of anaphylaxis as an ADR is a minor concern, but manageable.

Positives

• Clear FDA recommendations for BLA submission provide a defined regulatory path forward for nomlabofusp.
• The FDA is open to using skin frataxin (FXN) concentrations as a reasonably likely surrogate endpoint (RLSE), which could potentially expedite the approval process.
• Nomlabofusp has demonstrated significant increases in skin FXN levels, reaching a mean of 72% of healthy volunteer levels at Day 90 from 16% at baseline in the OLE study.
• Observed trends towards improvement in multiple clinical outcomes (mFARS, FARS-ADL, Modified Fatigue Impact Scale, 9 Hole Peg Test) in the OLE study are encouraging.
• Nomlabofusp is generally well-tolerated with long-term treatment, exhibiting high adherence rates for daily subcutaneous injections.
• Participation in the FDA's START pilot program provides enhanced communication and potential for expedited development for this rare disease therapy.
• Ongoing global Phase 3 study activities indicate progress towards a confirmatory trial to support full approval.
• The company maintains a solid financial position with $157.5 million in cash and investments as of March 31, 2025, providing a projected cash runway into Q2 2026.

Negatives

• The Biologics License Application (BLA) submission timeline has been refined/delayed to Q2 2026, indicating a longer development period than previously implied, to allow for the inclusion of additional safety data.
• Anaphylaxis has been identified as an adverse drug reaction likely related to nomlabofusp, requiring specific premedication strategies for certain patient populations.
• The observed improvements in clinical outcomes are described as 'trends' from an open-label extension study, which are not definitive results from a controlled, pivotal Phase 3 trial.

Risks

• The success, cost, and timing of Larimar's product development activities, nonclinical studies, and clinical trials, including nomlabofusp clinical and regulatory milestones and continued interactions with the FDA.
• Preliminary clinical trial results may differ from final clinical trial results, and earlier non-clinical and clinical data may not be predictive of the results or success of later trials.
• The FDA may not ultimately agree with Larimar's nomlabofusp development strategy or the acceptability of skin FXN as a surrogate endpoint for accelerated approval during future BLA review.
• Potential impact of public health crises on Larimar's future clinical trials, manufacturing, regulatory, nonclinical study timelines and operations, and general economic conditions.
• Larimar's ability and the ability of third-party manufacturers Larimar engages, to optimize and scale nomlabofusp's manufacturing process.
• Larimar's ability to obtain regulatory approvals for nomlabofusp and future product candidates.
• Larimar's ability to develop sales and marketing capabilities, whether alone or with potential future collaborators, and to successfully commercialize any approved product candidates.
• Larimar's ability to raise the necessary capital to conduct its product development activities.

Future Outlook

Larimar Therapeutics plans to submit its Biologics License Application (BLA) for nomlabofusp seeking accelerated approval in the second quarter of 2026, with a U.S. launch planned for early 2027. The company is also advancing a global Phase 3 study intended as the confirmatory trial to verify clinical benefit as required by the FDA's accelerated approval pathway.

Management Comments

• "We are thrilled to have clarity from FDA on the safety database recommendations following submission of safety information included in a briefing package from our nomlabofusp program. Importantly, we now have written recommendations from FDA on critical elements of the BLA submission including the safety database as well as the use of skin frataxin (FXN) concentrations as a reasonably likely surrogate endpoint (RLSE)." Carole Ben-Maimon, MD, President, and Chief Executive Officer.
• "Based on the FDA’s safety database recommendations and our plan to request approval to treat a broad population of patients including adults and children, we now plan to submit our BLA seeking accelerated approval in the second quarter of 2026." Carole Ben-Maimon, MD, President, and Chief Executive Officer.
• "Our participation in the START program has been incredibly valuable and continues to help us expedite clinical and regulatory development for the nomlabofusp program. We are on track to report data in September 2025 including data on the 50 mg dose from our OLE study, as well as adolescent pharmacokinetic (PK) run-in data. Nomlabofusp has the potential to be the first disease modifying therapy for FA and we look forward to expanding the clinical program to patients around the world with the initiation of our global Phase 3 study." Carole Ben-Maimon, MD, President, and Chief Executive Officer.
• "Our long-term OLE study is further advancing, with some participants now on treatment for up to 15 months. This includes exposure at both the 25 mg and 50 mg doses. The high adherence rates we are seeing for daily subcutaneous injections in participants over the long term is very encouraging. We have begun transitioning adolescents from the PK run-in study and have amended the protocol to include patients who have never participated in any of our prior clinical trials. Overall, we are pleased with our progress and the recommendations we now have from FDA on the safety database to achieve our near-term registrational goals." Dr. Rusty Clayton, Chief Medical Officer.

Industry Context

This announcement highlights the ongoing efforts in the biotechnology sector to develop treatments for rare neurodegenerative diseases like Friedreich's Ataxia, which currently has limited therapeutic options that address the underlying genetic deficiency. Larimar's nomlabofusp, if approved, would be the first disease-modifying therapy for FA, positioning it uniquely in a market with significant unmet medical need. The FDA's engagement through the START pilot program underscores a broader regulatory trend towards accelerating development for therapies targeting serious rare conditions.

Comparison to Industry Standards

• Friedreich's Ataxia affects approximately 20,000 patients globally, with about 5,000 in the U.S., representing a significant unmet medical need compared to more prevalent conditions, aligning with the industry's focus on orphan diseases.
• The current only approved treatment for FA does not address the underlying frataxin deficiency, making nomlabofusp a potential first-in-class disease-modifying therapy, which sets a high standard in rare disease drug development.
• The FDA's START pilot program, which selected Larimar as one of seven novel drug development programs, indicates that nomlabofusp meets a high bar for program readiness and potential to address serious unmet medical needs in rare neurodegenerative conditions, aligning with regulatory efforts to expedite promising therapies.
• The use of skin frataxin (FXN) concentrations as a 'reasonably likely surrogate endpoint' (RLSE) is a key regulatory strategy for accelerated approval in rare diseases, a pathway utilized by other companies developing therapies for conditions with clear biomarkers and high unmet needs.

Stakeholder Impact

• Shareholders: Potential for increased confidence due to clear FDA pathway and positive clinical trends, but also potential for short-term negative reaction due to BLA submission delay. Long-term value proposition tied to successful approval and commercialization.
• Patients (Friedreich's Ataxia): Hope for a first disease-modifying therapy, but a longer wait for potential market availability due to the refined BLA timeline. Continued access to nomlabofusp through ongoing clinical trials.
• Employees: Continued focus on clinical development and regulatory milestones.
• Regulatory Authorities (FDA): Continued collaboration through the START program, demonstrating a structured approach to drug development for rare diseases.

Next Steps

• Continue enrolling participants on the 50 mg dose in the Open Label Study.
• Plan to introduce lyophilized dosage form mid-2025.
• Plan to enroll patients who have not participated in a prior nomlabofusp trial into the Open Label Study.
• Considering enrolling children aged 2-11 years directly into the Open Label Study.
• Publication of nonclinical package data in a peer-reviewed journal this summer.
• Expected data from 30-40 participants in the OLE study in September 2025.
• Expected adolescent PK run-in data from 14 participants in September 2025.
• Biologics License Application (BLA) submission seeking accelerated approval planned for Q2 2026.
• Initiation of the global Phase 3 study, intended as the confirmatory study.
• Planned U.S. launch for early 2027.

Key Dates

Recommendation

Keywords

Larimar Therapeutics, nomlabofusp, Friedreich's Ataxia, FDA, Biologics License Application, BLA, accelerated approval, rare disease, clinical trial, biotechnology, frataxin, FXN, surrogate endpoint, START pilot program, neurodegenerative, orphan drug