Syndax Pharmaceuticals has announced that its Phase II trial of revumenib achieved its primary endpoint in certain patients with relapsed or refractory acute myeloid leukaemia (AML).
Despite this success, investors were unimpressed with the topline data, with Syndax’s stock dropping by 25.6%, from $21.78 per share at market close on 11 November to $16.21 a share at close on 12 November. Shares continue to trade lower than before the announcement, opening at $16.05 today (13 November).
The Phase I/II AUGMENT-101 trial (NCT04065399) evaluated the safety and efficacy of its experimental drug revumenib in adults with relapsed or refractory mutant NPM1 AML, a difficult-to-treat form of AML with specific genetic mutations. The trial enrolled adults with a median age of 65 years who had undergone extensive prior treatments; 75% had previously received AbbVie’s Venclexta (venetoclax), and 36% had tried three or more lines of therapy.
Among the 64 efficacy-evaluable patients from the Phase II cohorts, 23% achieved complete remission (CR) or CR with partial haematological recovery (CRh), including 12 patients with full remission and three with partial recovery. The median duration of response was 4.7 months, and 64% of tested patients were MRD-negative, showing no detectable cancer cells after treatment. The trial also reported an overall response rate (ORR) of 47%, with five responders proceeding to stem cell transplants.
Safety was assessed in 84 adult and paediatric patients. Four patients discontinued treatment due to treatment-related adverse events (TRAEs). More than 10% of patients reported Grade 3 or higher TRAEs and Grade 4 events included QTc prolongation – a condition that increases the risk of abnormal heart rhythms – and differentiation syndrome (DS), a potentially life-threatening condition.
The safety profile observed with revumenib in this population was consistent with previously reported Phase I data. Data from the Phase I portion of the study, announced in October 2023, showed an ORR of 63%, higher than in the Phase II section.
The treatment landscape for relapsed or refractory (R/R) mNPM1 AML remains challenging, with chemotherapy and therapies like AbbVie’s Venclexta more commonly used for other types of AML. Newer treatments, such as revumenib, are being explored in clinical trials to provide options for patients who do not respond to standard therapies. Revumenib works by blocking the interaction between menin, a tumour suppressor protein, and mixed lineage leukaemia (MLL) fusion proteins, which are key drivers of leukaemia.
Syndax and Kura Oncology are in a competitive race, both developing menin inhibitors that disrupt the same menin-MLL1 interaction, aiming for a share of the AML market. As of September 2024, Kura completed enrolment in its Phase II KOMET-001 trial (NCT04067336) of ziftomenib for R/R NPM1-mutant AML. However, revumenib may have the first-mover advantage as it awaits an approval in the KMT2A-rearranged subgroup of R/R AML and acute lymphocytic leukaemia, with a Prescription Drug User Fee Act (PDUFA) date of 26 December 2024.
According to GlobalData’s Pharma Intelligence Center, revumenib is projected to generate $634m by 2030, while ziftomenib could reach $583m in the same year.
GlobalData is the parent company of Pharmaceutical Technology.
