THE ARISING · Longevity & Healthspan
Sironax to Present Early Human Data on SARM1 Nerve-Protecting Drug
Sironax plans to present early clinical findings for its experimental SARM1 inhibitor in ALS and chemotherapy-related nerve damage. The company announcement supplies poster titles, not enough data to judge benefit or safety.
Sironax, a biotech based in Waltham, Massachusetts, has three posters on its drug SIR2501 at Neuroscience 2026, the Society for Neuroscience annual meeting. The meeting runs 14–18 November in Washington, DC.
SIR2501 targets an enzyme called SARM1. According to the company, SARM1 is a key driver of nerve damage in diseases such as ALS and chemotherapy-induced peripheral neuropathy, known as CIPN. CIPN is the numbness, tingling or pain in the hands and feet that some people live with after chemotherapy. The company reports that the FDA has given SIR2501 Fast Track designation for CIPN.
The drug works in an unusual way. Older SARM1 blockers go straight to the part of the enzyme where its work gets done. Sironax says those have shown potential side effects. SIR2501 is an allosteric inhibitor. It binds elsewhere on the enzyme and holds it in an inactive state. The aim is to protect nerves from degenerating without the same adverse effects. The company calls the drug first-in-class and says it showed strong neuroprotective effects across several preclinical models.
According to Sironax, global Phase 1b/2 trials in ALS and CIPN are ongoing.
Two of the three posters will be presented on 15 November in the ALS session. According to its title, one reports favorable safety and early evidence of biological activity in people with ALS. The other covers laboratory work in models of ALS, glaucoma and ischemic stroke.
The third poster is on 18 November, in the nerve damage and pain session. According to its title, it reports favorable safety, predictable pharmacokinetics (how the body absorbs and clears a drug) and early signals of protection against CIPN.
The announcement provides no patient numbers or doses. SIR2501 is not approved anywhere, and its human safety and efficacy have not been established.
Sironax is not built around one molecule. It is running clinical studies of SIR4156, which activates NAMPT, an enzyme involved in making NAD+, a molecule widely studied in aging research. It is also studying SIR9900, which blocks RIPK1, a protein tied to inflammation and a type of cell death. The company describes its pipeline as targeting degeneration, metabolic dysfunction and inflammation. Fierce Biotech named Sironax to its 2026 Fierce 15 list of promising private biotechs.
The posters in Washington, and the ongoing ALS and CIPN trials, will show how the early safety data are taking shape.