A combined therapy of azacytidine and nivolumab appears to be a safe and effective treatment for patients with relapsed/refractory acute myeloid leukemia (AML) according to a study published in Cancer Discovery.
Azacytidine is commonly used to treat newly diagnosed AML. However, although it promotes the activation of antitumor and viral defense gene pathways, it also activates the expression of PD-1 and PD-L1 antibodies, which are associated with decreased antileukemic response.
In the single arm trial, researchers tested if a combined treatment of azacytidine with the PD-1/PD-L1 inhibitor nivolumab would produce a more balanced treatment. The study included 70 patients with relapsed/refractory AML; median age, 70; and had received a median 2 prior therapies. Patients received azacytidine 75 mg/m2 for 7 days intravenously or subcutaneously, with nivolumab 3 mg/kg subcutaneously on days 1 and 14. Each treatment cycle was 28 days with repeated cycles every 4 to 6 weeks.
The overall response rate was 33%, with 15 patents in complete remission, 1 partial response, and 7 patients with hematologic improvement maintained for more than 6 months. Interestingly the overall response rate was greater (55%) in patients who had never received treatment with hypomethylating agents (HMA) such as azacytidine, compared with patients previously treated with a HMA (22%).
An increased presence of CD3 and CD8-positive cells in pretherapy bone marrow and peripheral blood were significant predictors of patients’ response. “Bone marrow CD3 and CD8 are relatively simple assays that should be incorporated to select patients in future trials,” noted the authors.
Daver N, Garcia-Manero G, Basu S, et al. Efficacy, safety, and biomarkers of response to azacitidine and nivolumab in relapsed/refractory acute myeloid leukemia: a non-randomized, open-label, phase 2 study [published online November 8, 2018]. Cancer Discov. doi: 10.1158/2159-8290.CD-18-0774