Blinatumomab in Relapsed/Refractory Burkitt Lymphoma

SIMPLE SUMMARY: 20–40% of patients with Burkitt lymphoma (BL) have relapsing or refractory (r/r) disease, and standard treatment for such patients is poorly established. An unexplored treatment option is the bispecific T-cell engager blinatumomab, as used for the treatment of r/r and minimal residual disease (MRD) positive B-cell precursor acute lymphoblastic leukemia (BCP-ALL). So far, data on the use of blinatumomab in r/r BL are limited. In this retrospective multi-center case series, we investigated blinatumomab treatment in nine patients with r/r BL after 1–3 previous therapy lines. Data on safety and efficacy were collected. No high-grade (≥grade 3) adverse effects (AEs) occurred, and use of blinatumomab was found to be safe. The best response to blinatumomab and survival data varied considerably among patients, but with five from nine patients responding, blinatumomab seems to have activity in patients with r/r BL. Our data suggest that blinatumomab could be further explored in r/r BL. ABSTRACT: In patients with relapsed/refractory Burkitt lymphoma (r/r BL), overall survival (OS) is poor, and effective therapies and evidence for the best therapy are lacking. The monoclonal antibody blinatumomab may represent a novel option. However, only limited data on the use of blinatumomab in r/r BL are so far available. This multi-center, retrospective case series investigated nine patients with r/r BL treated with blinatumomab. The safety of blinatumomab was assessed with respect to frequency and severity of adverse effects (AEs) infections, cytokine release syndrome (CRS) and neurotoxicity. Progression-free survival (PFS), OS and overall response rate (ORR) were analyzed to assess efficacy. No AEs > grade 2 occurred, and AEs were generally treatable and fully reversible. The best response to blinatumomab was complete remission in 3/9 patients and partial remission in 2/9, whilst 4/9 presented with progressive disease. Median PFS and OS were 2 and 6 months, respectively, ranging from 5 days to 32 months and 11 days to 32 months, respectively. Blinatumomab treatment was a successful bridging treatment to stem cell transplantation in 3/9 patients. The response to blinatumomab varied widely, and only one patient survived longer term, but activity in patients with r/r BL was evident in some patients, with its use being safe, warranting its prospective investigation.