STIMULUS MDS-US : Sabatolimab Added to HMA in Higher Risk MDS

This was a single arm, nonrandomized, open label, Phase II multicenter study of i.v sabatolimab added to FDA approved HMA agents of Investigator's choice (i.v/s.c/oral) in adult patients with intermediate, high or very high risk MDS as per IPSS-R criteria.

There were 4 separate periods of this study:

1. Screening period (signing of written informed consent through day of enrollment), 2. Core phase for up to 12 months, 3. Extension phase for efficacy and/or survival status (up to 12 months after the core phase), 4. Post-treatment safety follow-up period monitoring for AEs for 30 days following the last dose of azacitidine or decitabine or INQOVI (oral decitabine), or 150 days following the last dose of sabatolimab, whichever was later.

During the conduct of the study there were 2 updates to the Novartis development strategy for sabatolimab. Based on the results from the Phase II STIMULUS MDS-1 study, recruitment was halted for CMBG453B1US01 (STIMULUS MDS-US) on 30-Sep-2022. Novartis confirmed the decision to halt recruitment was not based on any safety findings or safety concerns. Patients who were on study treatment or in follow-up were continued as per the protocol. Furthermore, on 11-Jan-2024, all sabatolimab investigators were notified by Novartis that, based on decision taken in Dec-2023, that the sabatolimab development program (which included study CMBG453B1US01) would be terminated. After the decision was made to discontinue the sabatolimab development program, participants already enrolled in the CMBG453B1US01 study were prepared for closure; these close out activities took approximately 9 months. The actual last patient last visit date was 1 Sep 2024.