Phase II clinical trial of pazopanib in patients with acute myeloid leukemia (AML), relapsed or refractory or at initial diagnosis without an intensive treatment option (PazoAML).

We evaluated pazopanib (800 mg orally QD) in patients not eligible for intensive treatment with relapsed/refractory AML or at initial diagnosis. Patients receiving pazopanib for > 14 days were analyzed for safety, tolerability, and efficacy. Co-primary endpoints were cumulative response rate and reduction of bone marrow microvessel density. Twenty patients (median age 76 years, range 52-86) were treated. Fifteen had relapsed/refractory and five had newly diagnosed AML. Median ECOG performance status was 1 (range 1-3). Four patients had adverse, 15 intermediate, and 1 patient favorable cytogenetic/molecular risk (ELN 2010 criteria). The safety profile of pazopanib was as reported. The most common adverse events of any grade were gastrointestinal. Two patients achieved PR (blast reduction > 50%), 14 stable disease (SD), and 4 progressive disease. Median PFS was 65 days (95% CI 29-105). After the end of the study, 1 CRi and 1 CRp occurred on demethylating agents, and 1 CR upon alloSCT. In these patients, SD and improved general condition on pazopanib allowed therapy escalation. Median OS for the overall study population was 191 days (95% CI 87-435) and 1-year survival was 35%. There was no significant change in microvessel density. Clinical trial information: NCT01361334.