South San Francisco-based Nura Bio, Inc., a clinical-stage biopharmaceutical company developing neuroprotective small molecule therapies, has completed a USD 73.8 million Series B financing round alongside announcing clinical advances in both of its SARM1 inhibitor programs, including the first patient dosed in a Phase Ib/IIa ALS study.
The round was led by The Column Group, with participation from Euclidean Capital, Samsara BioCapital, and Sanofi Ventures. Proceeds will fund clinical proof-of-biology studies for Nura Bio's two pipeline candidates, NB-4746 and NB-9402. No prior funding rounds were detailed in the available disclosure. The Column Group also co-leads the Series B of Atavistik Bio, another allosteric small molecule company, indicating continued investor conviction in mechanistically differentiated neurological and rare disease approaches.
SARM1 is a neuronally enriched NAD hydrolase that functions as a central driver of axon degeneration. Inhibiting SARM1 is designed to interrupt the axon-intrinsic metabolic cascade that leads to nerve fiber loss — an early pathological feature shared across ALS, peripheral neuropathy, and ocular neurological conditions. Axon degeneration precedes neuronal cell death in many of these diseases, and early intervention is considered a potential route to structural and functional neuroprotection.
Nura Bio's lead candidate, NB-4746, is a first-generation oral, brain-penetrant, reversible orthosteric SARM1 inhibitor currently enrolling patients in a global Phase Ib/IIa ALS study. In a prior Phase I study in healthy volunteers, NB-4746 demonstrated a favorable safety profile and achieved target plasma and cerebrospinal fluid exposure levels — a meaningful pharmacokinetic milestone for a CNS-targeted agent. The company has now dosed the first ALS patient in the Phase Ib/IIa study, which is designed to generate clinical proof-of-biology data.
The second candidate, NB-9402, represents a mechanistically differentiated approach. It is an oral, covalent, irreversible, allosteric SARM1 inhibitor — meaning it binds SARM1 at a site distinct from the active site and forms a permanent bond, potentially enabling longer-lasting target suppression with less frequent dosing. NB-9402 has entered a Phase Ia first-in-human study in healthy volunteers, which the company said is expected to complete in 2026. Preclinical data indicated high potency and durable efficacy across neurological disease models.