Larimar Therapeutics (Nasdaq: LRMR) submitted the first module of a rolling Biologics License Application (BLA) to the Food and Drug Administration (FDA) seeking accelerated approval of nomlabofusp for Friedreich's ataxia (FA), a rare progressive neurological disease. The remaining modules are expected in the second half of 2026.

The submission follows FDA meeting minutes from a Type B multidisciplinary pre-BLA meeting, in which the agency confirmed the existing data package appears sufficient to support a BLA submission seeking accelerated approval, with skin frataxin (FXN) as a potential novel surrogate endpoint. The FDA also agreed to a rolling submission format.

Larimar also released updated data from its ongoing open-label study. As of a March 2026 data cutoff, 43 adolescent and adult participants had received at least one dose of nomlabofusp, with 22 remaining in the study and a maximum treatment duration exceeding 800 days.

At one year of treatment, all nine evaluable participants achieved skin FXN levels above 8.2 pg/µg, the threshold comparable to asymptomatic heterozygous carriers. Mean skin FXN rose from 3.7 pg/µg at baseline to 12.1 pg/µg at one year.

Among 13 participants completing one year of dosing, the mean modified Friedreich Ataxia Rating Scale (mFARS) score improved by 1.0 point, compared to a mean 1.6-point worsening in a matched natural history reference population from the Friedreich's Ataxia Clinical Outcome Measures Study (FACOMS). At 18 months, the mFARS improvement was 2.3 points versus a calculated 2.3-point worsening in the FACOMS reference group.

Of six non-ambulatory participants at baseline, one became ambulatory after one year. None of the seven ambulatory participants progressed to non-ambulatory status at one year.

On safety, 10 of 43 participants experienced anaphylaxis, with nine of those having prior exposure to nomlabofusp. All affected participants returned to their usual state of health following standard treatment. The most common adverse events were mild to moderate injection site reactions.

Larimar said it expects to dose the first patient in a global confirmatory Phase 3 study in the third quarter of 2026 and is targeting a mid-2027 launch if approved.