Why Is Inherited Rare Disease Focused-Larimar Therapeutics Stock Trading Lower Today?

Larimar Therapeutics Inc LRMR released topline data and completed its four-week, placebo-controlled Phase 2 dose exploration study of nomlabofusp (CTI-1601) in participants with Friedreich’s ataxia (FA). 

Friedreich’s ataxia is an inherited disorder that affects some of the body’s nerves. It is caused by a defect (mutation) in a gene labeled FXN, which carries the genetic code for the production of a protein called frataxin.

Nomlabofusp was generally well tolerated and demonstrated dose-dependent increases in frataxin (FXN) levels.

Median changes in FXN levels from baseline for the 25 mg and 50 mg cohorts of nomlabofusp

• Skin cells: 2.81 pg/µg for the 25 mg cohort and 5.57 pg/µg for the 50 mg cohort.
•  Buccal cells: 0.56 pg/µg for the 25 mg cohort and 0.72 pg/µg for the 50 mg cohort.

All treated patients showed increases in FXN levels in skin cells, and most patients also demonstrated increases in FXN levels in buccal cells.

At Day 14, all patients with quantifiable levels at baseline and Day 14 treated with 50 mg of nomlabofusp achieved FXN levels in skin cells greater than 33% of the average level found in healthy volunteers, and 3 of the patients achieved levels greater than 50% of the average healthy volunteer level.

While FXN levels measured in buccal cells show a high degree of correlation with FXN levels measured in skin cells, higher variability in FXN levels was seen in buccal cells compared to skin cells in both the multiple ascending dose study and the Phase 2 dose exploration study. 

The open-label extension study was initiated in January 2024 to dose 25 mg daily of nomlabofusp, with dosing anticipated to start later this quarter, with initial data expected in the fourth quarter of 2024.

The company initiated discussions with the FDA on using tissue frataxin levels as a novel surrogate endpoint to support a potential Biologics License Application submission for accelerated approval targeted for the second half of 2025.

As of December 31, 2023, Larimar had cash, cash equivalents, and marketable securities totaling $86.8 million, which is expected to provide a runway into the first quarter of 2025.

Price Action: LRMR shares are down 9.73% at $7.01 on the last check Monday.

Photo via Darko Stojanovic from Pixabay