Efficacy and safety of blinatumomab for CD19 + acute leukemias in patients historically excluded from clinical trials due to comorbidities

Background

Blinatumomab has proven efficacy in the frontline, consolidation, and relapsed/refractory settings in B cell acute lymphoblastic leukemia. Its efficacy and safety among patients commonly excluded from clinical trials are unknown.

Patients and Methods

This single center, retrospective cohort study included patients treated for acute leukemia with blinatumomab with the following pre-existing conditions: liver dysfunction, renal impairment, central nervous system (CNS) conditions, autoimmune disease, solid organ transplantation, or uncontrolled infection. Rates of blinatumomab completion, efficacy outcomes, cytokine release syndrome (CRS), neurotoxicity (ICANS), and adverse events specific to the impaired organ leading to inclusion were assessed.

Results

Thirty-four patients were included, and 88 % completed at least one cycle of blinatumomab. One patient stopped prematurely due to toxicity and three due to lack of response in the relapsed/refractory setting. Response rates and survival were similar by treatment setting to those treated in clinical trials. The 60-day cumulative incidence of grade ≥ 2 CRS and ICANS were 23.5 % and 20.8 %, respectively. No excess liver injury, ICANS, autoimmune flares, organ rejection, or infections were observed in cohorts defined by impairment of each system.

Conclusion

Blinatumomab was successfully administered to the vast majority of patients with a baseline condition that would have led to clinical trial exclusion. Adverse events generally occurred at rates similar to prior clinical trials. These data provide the basis to consider removing certain exclusion criteria from future studies involving blinatumomab, allowing more patients to benefit from its efficacy.