Cullinan Therapeutics Inc. (NASDAQ: CGEM) announced that the U.S. Food and Drug Administration granted Orphan Drug Designation to CLN-049 for treating relapsed/refractory acute myeloid leukemia.

CLN-049 is an investigational FLT3xCD3 T cell engager designed to target FLT3-expressing leukemia cells. The drug binds to both mutated and non-mutated FLT3, enabling targeted action regardless of FLT3 mutational status.

The FDA's Orphan Drug Designation applies to drugs intended to treat rare diseases affecting fewer than 200,000 people in the United States. The designation provides development incentives including tax credits for clinical trials, exemption from certain FDA user fees, and potential seven-year market exclusivity following approval.

"FDA Orphan Drug Designation for CLN-049 emphasizes both the urgent need for new therapies for people living with relapsed or refractory acute myeloid leukemia – including patients with TP53-mutated AML who currently face a particularly poor prognosis – and the potential of this FLT3-directed T cell engager to expand treatment options," said Jeffrey Jones, Chief Medical Officer at Cullinan Therapeutics.

CLN-049 previously received Fast Track designation from the FDA for treating relapsed/refractory AML. The drug is currently being studied in Phase 1 trials for patients with relapsed/refractory AML or myelodysplastic syndrome, and in a separate Phase 1 study for AML patients with measurable residual disease.

According to the press release, approximately 22,000 people are diagnosed with AML annually in the United States, with about half as many deaths from the disease. Five-year survival rates for patients with relapsed or refractory disease are 10% or less.