FDA feedback clears path for NSB’s StemSmart Crohn’s trial

FDA supports six of seven trial questions

NeuroScientific Biopharmaceuticals Limited (ASX:NSB) has cleared a significant regulatory hurdle for its planned StemSmart Phase 2 trial in refractory Crohn’s disease, with the US Food and Drug Administration providing favourable responses to six of the seven questions raised at a Pre-Investigational New Drug meeting.

The FDA agreed with NSB’s proposed Phase 2 clinical design, accepted the existing human weight-of-evidence package from people previously treated with StemSmart, and said no additional non-clinical studies were required. It also supported the company’s proposed product release-testing strategy.

Manufacturing control remains the open issue

The unresolved matter is specific but important: the FDA wants NSB to strengthen its manufacturing control strategy to ensure StemSmart is free from viral contamination. NSB said it agrees with the feedback and is implementing the required testing, which it expects to have minimal impact on its timetable.

The outcome follows NSB’s earlier effort to secure formal FDA engagement for the programme, after the regulator scheduled a Pre-IND meeting to review the proposed US trial. That meeting had been presented as a gateway to refining the trial design ahead of a planned IND submission, and the regulator’s response now gives the company clearer parameters for the next stage. The FDA meeting was secured in the company’s FDA Pre-IND meeting coverage in August.

Phase 2 start still depends on execution

NSB is targeting trial initiation in Australia and the United States by the end of calendar 2026. That remains a target rather than a confirmed start date: regulatory, manufacturing and operational requirements still need to be completed, including the viral contamination testing and the future IND process.

The company’s case for advancing StemSmart includes earlier human treatment data, but the FDA feedback does not establish efficacy, safety or approval for the therapy. NSB previously reported an 80% clinical response rate among a small group of fistulising Crohn’s disease patients treated under Australia’s Special Access Scheme, a result that supported the company’s decision to pursue Phase 2 development but is not a substitute for controlled trial evidence.

For NSB, the immediate question is no longer whether the regulator has accepted the broad trial concept. It is whether the company can complete the manufacturing controls, submit the IND and activate the study on schedule without creating a new operational or funding constraint.