Core Viewpoint - AB Science has received regulatory approval from several European countries to initiate the third stage of its Phase I/II study combining AB8939 with venetoclax for treating acute myeloid leukemia (AML), indicating potential advancements in treatment options for patients with relapsed/refractory AML [1][4]. Group 1: Study Details - The third stage of the study has been approved in France, Germany, Spain, and Greece, focusing on determining the maximum tolerated dose (MTD) of AB8939 [2]. - The first two stages of the Phase I study involved 28 and 13 patients, respectively, establishing the MTD of AB8939 at 21.3 mg/m² after both 3 and 14 consecutive days of treatment [3]. - The current stage will evaluate the MTD after 14 consecutive days of treatment with AB8939 in combination with venetoclax, a standard treatment for AML [3][6]. Group 2: Treatment Rationale - The combination of AB8939 and venetoclax is expected to have low hematologic toxicity, potentially making it less toxic than the current standard treatment of azacitidine plus venetoclax [5]. - Both compounds target different mechanisms in cancer cells, which may lead to additive or synergistic effects in efficacy [5][9]. - AB8939 destabilizes microtubules, preventing cancer cell division, while venetoclax inhibits BCL2, promoting apoptosis in cancer cells, thus addressing resistance mechanisms [7][13]. Group 3: Market Potential - The estimated market potential for AML treatments exceeds €2 billion annually, with significant addressable markets in the United States, Europe, and Asia-Pacific [11][12]. - The total incidence of AML in the United States, Europe, and Asia-Pacific is approximately 79,100 cases, with a significant portion being poor responders to standard therapies [12][15]. Group 4: Intellectual Property and Regulatory Status - AB8939 is protected by patents until 2026, with potential extensions and additional protections for specific uses in AML, extending to 2044 for certain chromosomal abnormalities [16][18]. - The drug has received orphan drug designation from both the EMA and FDA, granting it marketing exclusivity for 10 years in Europe and 7 years in the US [19].