Cullinan reports updated CLN-049 AML data ahead of ASH presentations

Cullinan Therapeutics said on November 4, 2026 that it will present updated data from the Phase 1 dose escalation study of CLN-049, a FLT3xCD3 T cell engager, in patients with relapsed or refractory acute myeloid leukemia or myelodysplastic syndrome at the 68th American Society of Hematology Annual Meeting, held December 12-15 in New Orleans.

As of the data cutoff, 87 patients, 76 with AML and 11 with MDS, were enrolled across 13 cohorts spanning a target dose range of 1.5-24 µg/kg.¹ Of these, 80 patients were efficacy evaluable.¹

At the 6 µg/kg target dose level, the CRc rate was 19% (3/16 patients, all CR) and the ORR was 25%. At the 12 µg/kg target dose level, the CRc rate was 21% (6/29 patients, 2 CR) and the ORR was 45%.¹ Among patients treated at the 12 µg/kg target dose level who started with a step-up dose of 1.5 µg/kg or lower, the CRc rate rose to 26% (5/19 patients, 2 CR) and the ORR reached 53%.¹

On safety, cytokine release syndrome occurred in 36% of patients on a single step-up dose, including the only Grade 3 event, while a two step-up dosing regimen reduced CRS incidence to 26% and limited severity to Grade 1 and 2.¹ ICANS occurred in 6% of patients, with one Grade 3 event, and all cases were self-limiting.¹ The two step-up regimen also cut transaminase elevations to 4% of patients, and these elevations were asymptomatic and reversible.¹

Cullinan said these dose levels showed anti-leukemic activity with count recovery in a broad relapsed or refractory AML and MDS population, to be explored further in the ongoing Phase 2 trial.¹ CLN-049 holds Orphan Drug and Fast Track designations from the FDA for relapsed or refractory AML.¹