Nkarta's Updated Data From Leukemia Study Fails To Cheer Investors

Nkarta Inc NKTX announced updated data from the Phase 1 study of NKX101 to treat patients with relapsed or refractory (r/r) acute myeloid leukemia (AML).

NKX101 is an allogeneic, off-the-shelf cell therapy candidate composed of NK cells derived from healthy donors and engineered to target NKG2D ligands on cancer cells.

Four of six patients in one dose expansion cohort achieved a best composite complete response (67% CR/CRi rate) after receiving at least one cycle of NKX101.

3 of 6 achieved a complete response with hematologic recovery (50% CR rate).

Two of the 4 reported complete responses were MRD (measurable residual disease) negative.

A cycle in this cohort consisted of three weekly doses of NKX101 at 1.5 billion cells per dose after treatment with fludarabine (Flu) and Ara-C (cytarabine, a well-established drug in treating AML) for lymphodepletion.

Nkarta plans to enroll 12 to 20 additional patients in the Phase 1 trial expansion cohort and provide an update in 1H of 2024.

In patients with r/r AML that received Flu/Cy lymphodepletion and the highest doses of NKX101 (3 weekly doses at 1 billion or 1.5 billion cells per dose), 4 of 18 achieved CR/CRi (22% CR/CRi rate) and 3 of 18 achieved a complete response with hematologic recovery CR (17% CR rate). 

There were no CRs at the lower doses of NKX101.

Price Action: NKTX shares are down 34.20% at $2.98 on the last check Tuesday.