NB-4746

Nura Bio is a private biotech in South San Francisco and NB-4746 is its lead drug. It raised more than $140 million in its first funding rounds and a further $73.8 million in June 2026, led by The Column Group with Euclidean Capital, Samsara BioCapital and Sanofi Ventures. It is also testing a second SARM1 blocker, NB-9402, in healthy volunteers.

SARM1 is an enzyme inside nerve cells that, once switched on by injury or stress, burns up the cell's energy molecule NAD and makes the long nerve fibre (axon) fall apart. Blocking it protects nerve fibres in lab and animal studies, and rare overactive versions of the SARM1 gene are found more often in people with ALS. But removing SARM1 entirely did not slow disease in the most widely used ALS mouse model (SOD1), so it is unclear how much this pathway drives ALS. Eli Lilly is also starting trials of its own SARM1 blocker in ALS.

The current trial (NCT07369076) doses people with ALS, not healthy volunteers. Part A compares two doses with placebo for 28 days; Part B compares the chosen dose with placebo for 12 weeks and looks at whether it lowers neurofilament light (NfL), a blood marker of nerve damage. That is why it counts as Phase 1/2, but its main goal in both parts is safety, so it is not designed to show whether the drug slows ALS. The registry lists a start date of 4 March 2026; Nura Bio said dosing had begun by June 2026. Before this, two Phase 1 studies in healthy volunteers were completed in Australia.

No results in people with ALS have been reported. In healthy volunteers, Nura Bio says NB-4746 was well tolerated, had no serious side effects and reached the levels it was aiming for in blood and spinal fluid; these results are from press releases and have not been published in full. The company says it protected nerves in animal models, including ALS, but most drugs that work in mice do not work in people.

This is the most favourable result reported. See all key studies for the full picture.

The trial is for adults aged 18 to 80 with ALS who can still eat by mouth and have breathing capacity of at least 60% of normal. Symptoms must have started within 48 months for Part A and within 24 months for Part B. People on stable riluzole or edaravone can join; people taking or planning tofersen cannot.

ClinicalTrials.gov estimates the main part of the trial will finish in April 2027 and the whole study, including the extension, in February 2028. Nura Bio has not publicly said when it will share results.

The ALS trial is recruiting at 12 sites: six in Australia, three in Canada (Fredericton, Toronto, Montreal), Utrecht in the Netherlands, and Krakow and Warsaw in Poland. There are no US sites listed. For 28 days, people have a 1 in 3 chance of placebo; for the 12-week part, a 1 in 2 chance. Everyone who finishes can choose to take NB-4746 in an extension. There is no expanded access programme.

• NB-4746-201 (NCT07369076) recruiting · Australia (Sydney, Brisbane, Adelaide, Melbourne, Perth), Canada, Netherlands, Poland
• NB-4746 Phase 1 (healthy volunteers) (ACTRN12623000476639) completed · Australia