Affimed N.V. recently presented data from the first-in-human Phase 1 study of AFM28 at the 66th ASH Annual Meeting and Exposition. This study focused on patients with relapsed/refractory acute myeloid leukemia (R/R AML), a challenging condition to treat. The trial included 29 patients who had undergone multiple prior treatments, with a median of two treatment lines before the study. According to the 2022 European LeukemiaNet (ELN2022) guidelines, 86% of these patients had an adverse risk profile.
AFM28 was administered intravenously once a week across six dose levels, ranging from 25 mg to 300 mg. The treatment was well tolerated, with the most common adverse events being infusion-related reactions (IRRs), observed in 45% of patients. All IRRs were mild to moderate (Grade 1 or 2), and one patient experienced grade 1 cytokine release syndrome (CRS). Notably, there were no instances of neurotoxicity or immune-effector related side effects.
At the 250 mg dose level, one out of six patients achieved complete remission (CR) and remained on treatment for 6.5 months. At the higher dose of 300 mg, one complete remission and three complete remissions with incomplete hematologic recovery (CRi) were observed among ten evaluable patients, resulting in a combined complete remission rate (CRcR) of 40%. Four of these ten patients are still undergoing treatment, with the potential for further improvement in their responses.
AFM28 is a tetravalent, bispecific CD123- and CD16A-binding ICE® molecule designed to engage natural killer (NK) cells to initiate the killing of leukemic cells through antibody-dependent cellular cytotoxicity, even at low CD123 expression levels. This innovative approach offers a new immunotherapeutic strategy for patients with R/R AML. The Phase 1 study of AFM28 is ongoing, and it is currently being developed as a monotherapy for patients with R/R AML (NCT05817058).
