Thrombopoietin receptor agonist for treating bone marrow aplasia following anti-CD19 CAR-T cells-single-center experience.

Anti CD-19 chimeric antigen receptor T (CAR-T) cells demonstrate effective early anti-tumor response; however, impaired hematopoietic recovery is observed in about 30% of patients with prolonged cytopenia appearing as an unmet need for optimal treatment. All adult patients given commercially available anti CD-19 CAR-T for diffuse large B cell lymphoma (DLBCL) were screened at 21-28 days after CAR-T infusion for cytopenia. In case of severe persistent cytopenia, patients were given TPO receptor agonists. Initial dose of eltrombopag was 50 mg/day and gradually increased to a maximal dose of 150 mg/day. Romiplostim was given as subcutaneous injection once a week for 2 doses (125 mcg). Response was defined as transfusion independency along with resolution of severe neutropenia (ANC > 500 /microL) and/or platelets > 20,000/microL for three consecutive values on different days. TPO receptor agonists were tapered down when response was met. From May 2019 to December 2021, 93 patients were eligible (74%, tisagenlecleucel and 26%, axicabtagene ciloleucel). The median age was 69 (range, 19-85) years. Six patients (6.5%) (tisagenlecleucel, n = 4 or axicabtagene ciloleucel, n = 2) demonstrated prolonged severe cytopenia and were treated with TPO receptor agonists (eltrombopag, n = 4; romiplastim, n = 1, both drugs, n = 1). Median time from CAR-T infusion to initiation of TPO receptor agonist was 43 (range, 21-55) days. All patients were transfusion-dependent and were given daily GCSF prior to TPO receptor agonist administration. Response to TPO receptor agonists was seen in all 6 patients. Median time from TPO receptor agonist initiation to resolution of cytopenia was 22 (range, 8-124) days for Hb, 27 (range, 6-38) days for platelets, and 29 (range, 7-61) days for neutrophils. A complete resolution of all blood counts (ANC > 500 /microL and platelets > 20,000/microL and hemoglobin > 8 gr/dL) was seen in 5/6 patients. No toxicity was observed during the therapy course. This paper supports further investigation of TPO receptor agonists in the treatment of persistent cytopenia following CAR-T cell therapy.

Venetoclax and donor lymphocyte infusion for early relapsed acute myeloid leukemia after allogeneic hematopoietic cell transplantation. A retrospective multicenter trial.

Prognosis in patients with post allogeneic HCT-early relapse of acute myeloid leukemia (<6 months post HCT) is dismal and response to salvage treatment is < 20%. In addition, majority of patients at this early point are unable to withstand intensive salvage chemotherapy. We hypothesized that the combination of donor lymphocyte infusion (DLI) and venetoclax may result in increased response in this difficult to treat patient group. We retrospectively analyzed 22 patients from February 2017-December 2019, who were given the Venetoclax/DLI combination. Median age was 65 (43-75) years. There were no cases of tumor lysis syndrome. Microbiology documented infections occurred in 8 patients (36%). Majority were able to tolerate the protocol without admissions. Acute GVHD was observed in 4 (18%) patients and cGVHD was observed in 6 (27%) patients. Overall response was observed in 11 (50%) patients (CR, n = 4; CRi, n = 1; CRp, n = 4; MLFS n = 2). Median time to response was 28 (18-67) days and median cycles of venetoclax 2 [1-8] and duration of response were 135 (31-564) days. Median survival was 6.1 months (95% CI .73-11.4). Cox regression model for survival showed decreased WBC at relapse, GVHD and better performance status were associated with better survival. These results may endorse the hypothesis that enhancing alloreactivity combined with venetoclax is safe and efficacious and should be further investigated in prospective trials.