Nomlabofusp Gains FDA Breakthrough Status, Challenges Biogen’s Skyclarys with Accelerated Approval
Larimar Therapeutics’ lead asset nomlabofusp received FDA breakthrough therapy designation for Friedreich’s ataxia and secured FDA agreement to use skin frataxin levels as a surrogate endpoint ahead of a planned June 2026 filing. Biogen’s Skyclarys, the only approved FA therapy, faces potential accelerated competition in a limited treatment landscape.
1. Larimar’s regulatory milestone and filing plans
The FDA granted breakthrough therapy designation to nomlabofusp for adult and pediatric Friedreich’s ataxia after interim open‐label data showed skin frataxin increases and directional improvement across four clinical measures. The agency agreed to consider skin FXN levels as a novel surrogate endpoint, paving the way for Larimar’s planned regulatory submission in June 2026 following top‐line data due in Q2.
2. Competitive pressure on Biogen’s Skyclarys
Biogen’s Skyclarys remains the sole approved treatment for FA but now faces potential early competition if nomlabofusp secures accelerated approval. In a market with limited options, Larimar’s faster approval pathway could erode Skyclarys’ revenue potential in the coming years.