The US Food and Drug Administration (FDA) has granted fast track designation to Sumitomo Pharma America’s (SMPA) DSP-5336 for the treatment of relapsed or refractory acute myeloid leukaemia (AML).
DSP-5336, a small molecule inhibitor, targets the menin and mixed-lineage leukaemia (MLL) protein interaction crucial in gene expression and biological pathways related to cell growth and hematopoiesis.
The company is carrying out Phase I/II study of DSP-5336 in patients with relapsed or refractory AML with a mixed lineage leukaemia rearrangement (MLLr) or nucleophosmin mutation (NPM1m).
In preclinical studies, DSP-5336 demonstrated selective growth inhibition in human acute leukaemia cell lines with KMT2A (MLL) rearrangements or NPM1 mutations.
It also influenced the expression of genes associated with leukaemia and differentiation in these cell lines.
The ongoing clinical evaluation of DSP-5336's safety and efficacy is part of a Phase I/II dose escalation/dose expansion study in patients with relapsed or refractory acute leukaemia.
The treatment has been well-tolerated, without dose-limiting toxicity. No significant cardiac signals or treatment-related discontinuations or deaths have been reported.
DSP-5336 has shown no significant drug-drug interactions with azoles and repeat dosing has resulted in minimal to no pharmacokinetic accumulation.
Objective response rates were observed in 57% of patients, including those with NPM1 mutation and KMT2A (MLL) rearrangement, with 24% achieving complete remission or complete remission with partial haematologic recovery.
SMPA oncology chief medical officer Jatin Shah said: “Management of AML continues to be challenging with limited options for which there are currently no approved targeted therapies to treat AML with KMT2A (MLL) rearrangements or NPM1 mutations, leaving a serious unmet medical need.
“DSP-5336 has shown promising clinical activity, and menin inhibitors have tremendous potential to impact the outcomes of these types of acute leukaemia.
“We are excited by these early results and FDA fast track designation, and look forward to working closely with the agency and our collaborators to rapidly advance this programme with the goal of providing a well-tolerated and effective targeted treatment option for patients with relapsed or refractory acute myeloid leukaemia.”
