Gemtuzumab ozogamicin in combination with vorinostat and azacitidine in older patients with relapsed or refractory acute myeloid leukemia: a phase I/II study.

Epigenetic therapeutics such as the histone deacetylase inhibitor, vorinostat, and the DNA methyltransferase I inhibitor, azacitidine, enhance gemtuzumab ozogamicin efficacy in vitro. We therefore investigated vorinostat/azacitidine/gemtuzumab ozogamicin in 52 adults aged 50 years or over with acute myeloid leukemia requiring therapy for first relapse (remission duration ≤ 12 months) or primary refractory disease in a phase I/II trial. Vorinostat and gemtuzumab ozogamicin were escalated step-wise during the phase I portion of the trial. Vorinostat (400 mg/day orally from Days 1-9), azacitidine (75 mg/m(2)/day intravenously or subcutaneously from Days 1-7), and gemtuzumab ozogamicin (3 mg/m(2)/day intravenously on Days 4 and 8) were identified as the maximum tolerated dose. Among the 43 patients treated at this dose, 10 achieved a complete remission and 8 achieved a complete remission with incomplete blood count recovery, for an overall response rate of 41.9% (exact 95% confidence interval (CI): 27.0-57.9%). Four of these 18 patients (2 with complete remission and 2 with complete remission with incomplete blood count recovery) had persistence of minimal residual disease by flow cytometry at the time of best response. Four patients died within 28 days of treatment initiation. Median overall survival for the 18 patients achieving complete remission/complete remission with incomplete blood count recovery was significantly longer than for those 21 patients who failed therapy but lived at least 29 days after treatment initiation (224.5 days (range 70-798) vs. 95 days (range 36-900); P=0.0023). These data indicate that vorinostat/azacitidine/gemtuzumab ozogamicin has activity in this difficult-to-treat acute myeloid leukemia patient subset. (ClinicalTrials.gov: identifier 00895934).

Phase 1/2 trial of GCLAM with dose-escalated mitoxantrone for newly diagnosed AML or other high-grade myeloid neoplasms.

Outcomes with "7 + 3" are often unsatisfactory in acute myeloid leukemia (AML). Trials demonstrating improved outcomes with high-dose cytarabine, addition of cladribine, or escalated anthracycline doses prompted a phase 1/2 study (NCT02044796) of G-CSF, cladribine, high-dose cytarabine, and dose-escalated mitoxantrone (GCLAM) in adults with newly-diagnosed AML or other high-grade myeloid neoplasms. One hundred and twenty-one patients, median age 60 (range 21-81) years, were enrolled. In phase 1, cohorts of 6-12 patients were assigned to 12-18 mg/m2/day of mitoxantrone as part of GCLAM. Because all dose levels were well-tolerated, mitoxantrone at 18 mg/m2 was declared the recommended phase 2 dose (RP2D). 74/94 (79%) patients treated at the RP2D achieved a complete remission (CR; 67/74 without measureable residual disease [MRD]) for an overall MRDneg CR rate of 71% (primary phase 2 endpoint). Seven patients achieved a CR with incomplete blood count recovery (CRi; 7%, 5 MRDneg) for a CR/CRi rate of 81/94 (86%). Four-week mortality was 2%. After adjustment, the MRDneg CR and CR/CRi rates compared favorably to 100 matched controls treated with 7 + 3 at our center and 245 matched patients treated with 7 + 3 on a cooperative group trial. Our data indicate GCLAM with mitoxantrone at 18 mg/m2/day is safe and induces high-quality remissions in adults with newly-diagnosed AML.