Syndax Pharmaceuticals Inc (NASDAQ:SNDX) revealed updated data from the Phase 1 dose-escalation portion of the AUGMENT-101 trial of SNDX-5613 in patients with mutant nucleophosmin (mNPM1) or mixed-lineage leukemia rearranged (MLLr) relapsed/refractory acute leukemias.

• The data were featured at the American Society of Hematology (ASH) Annual Meeting.
• Across evaluable patients with mNPM1 (n=13) or MLLr (n=38) who received at least one dose of SNDX-5613, the overall response rate (ORR) was 55%, with a complete response with the partial hematologic recovery (CR/CRh) of 24%.
• Nine patients proceeded to stem cell transplant. 
• The ORR in evaluable patients harboring an NPM1 mutation was 38%, with a CR/CRh rate of 23%. 
• The ORR in evaluable patients harboring an MLL-rearrangement was 61%, with a CR/CRh rate of 24%.
• The overall minimal residual disease (MRD) negative rate was 31%. 
• The median time to response to patients achieving a CR/CRh was two months. The median duration of response (DOR) was not reached.
• SNDX-5613 was well-tolerated, with no discontinuations due to treatment-related adverse events observed in heavily pretreated patients. 
• The only dose-limiting toxicity observed was Grade 3 QT prolongation. 
• Differentiation syndrome was reported in 14% of patients, with all cases being mild or moderate and readily managed with standard therapies.
• Related Link: Syndax Pharma, Incyte Ink Licensing Pact For Graft Vs. Host Disease Candidate.
• Price Action: SNDX shares are trading 1.55% higher at $18.11 premarket on the lat check Tuesday.
• Check out our coverage of the American Society of Hematology (ASH) Annual Meeting 2021 here.