Syndax Pharmaceuticals, Inc. announced the presentation of positive data from the pivotal AUGMENT-101 trial in pediatric patients with relapsed/refractory (R/R) KMT2A-rearranged (KMT2Ar) acute myeloid leukemia (AML) and acute lymphoid leukemia (ALL) treated with revumenib, a first-in-class menin inhibitor. The pediatric data was featured in a Plenary Session titled "Pivotal Phase 2 Results of AUGMENT-101 for Revumenib in KMT2Ar Acute Leukemia: Pediatric Experience" at the 2024 American Society of Pediatric Hematology/Oncology (ASPHO) Conference held April 3 ? 6, 2024 in Seattle, Washington.

The presented data include efficacy and safety findings for pediatric patients with R/R KMT2Ar acute leukemia from the pivotal Phase 2 portion of the AUGMENT-101 study. Of the 57 patients enrolled in AUGMENT-101 with central confirmation of their KMT2Ar status and sufficient follow-up to be included in the efficacy-evaluable population, 13 (23%) were less than 18 years old with a median age of 5 years. The pediatric patients were heavily pretreated with a median of 4 prior lines of therapy including 8 (62%) that received prior venetoclax, 2 (15%) that received CAR-T and 6 (46%) that received prior hematopoietic stem cell transplant (HSCT).

In this population, the complete remission (CR) or CR with partial hematological recovery (CRh) rate was 23% (3/13; 95% CI: 5.0, 53.8), with a median time to CR or CRh of 2.3 months (95% CI: 1.0, 3.9). The overall response rate1 was 46% (6/13), and the composite response rate2 (CRc) was 39% (5/13). Sixty percent (3/5) of CRc patients achieved minimal residual disease negative status.

The median overall survival was 6.9 months (95% CI, 2.3?not reached). Four (67%) of the 6 patients who achieved an overall response underwent HSCT, two of whom did not achieve a CR or CRh prior to transplant. Half (2/4) of the patients who underwent HSCT received post-transplant maintenance with revumenib and had been in remission for 6 and 9 months at the time of the July 24, 2023 data cutoff.

Revumenib was well-tolerated, and the safety profile was consistent with the Company's previously reported data. In the safety-evaluable patient population, Grade 3 or greater treatment-related adverse events that occurred in greater than 10% of patients included febrile neutropenia (13%; 3/23) and decreased neutrophil count (13%; 3/23). Grade 3 or greater differentiation syndrome was observed in 9% (2/23) of patients and Grade 3 QTc prolongation was observed in 4% (1/23) of patients.

No treatment-related discontinuations or dose reductions due to adverse events occurred in the trial.