Affimed presents updated data from AFM28

Affimed presented a poster highlighting new preclinical data for its Innate Cell Engager AFM28 targeting CD123 and CD16A at the 64th American Society of Hematology Annual Meeting and Exposition in New Orleans, Louisiana. The data demonstrated the ability of AFM28 to effectively redirect allogeneic NK cells and induce depletion of CD123-positive leukemic blasts and leukemic stem cells in ex vivo patient samples, underscoring its potential as a novel therapeutic agent in AML. AFM28 is a novel ICE in development for treatment of patients with myeloid diseases that have undergone multiple prior treatments and have relapsed or are refractory to standard of care. It is designed to bind to natural killer cells and CD123-positive tumor cells to induce tumor cell killing. To date, the program has shown strong anti-tumor activity in vivo while maintaining a good safety profile.AML is a difficult-to-treat disease with low cure rates and significant toxicities associated with available therapies. There is an urgent need for new approaches that are effective, provide long-term, relapse-free survival and are better tolerated. AFM28 holds promise as a novel safe and effective therapeutic that could address the needs of underserved patients with AML. The poster presented at ASH featured detailed preclinical evaluations further characterizing AFM28 and its mechanisms of action in models of AML. The data confirmed a concentration-dependent, NK cell-mediated lysis of CD123-positive target cells in different tumor lines, irrespective of low CD123 expression or mutational status. In addition, high CD64 expression, which negatively affects antibody-dependent cellular cytotoxicity of conventional and Fc-enhanced anti-CD123 antibodies, did not affect AFM28 efficacy. A critical factor for long-term remission in AML patients is the efficient and safe depletion of leukemic blasts and corresponding stem cells. In ex vivo AML and MDS bone marrow samples, AFM28 induced the depletion of CD123-positive leukemia stem cells and leukemic progenitor cells while sparing healthy cells, suggesting the ability to induce deep, anti-tumor responses without irreversible bone marrow suppression. The ICE also showed inhibition of tumor growth in murine AML models, underscoring the anti-tumor activity of the program. Affimed remains on track to initiate clinical development of AFM28 with a first-in-human phase 1 monotherapy trial in adult patients with R/R AML in the first half of 2023. In addition, Affimed plans to investigate AFM28 in combination with allogeneic NK cell therapy after a safe starting dose has been determined.