A real-world study of stem cell boost for CAR T-related hematologic toxicity in RRMM

Real-world results from a retrospective, multicenter study, evaluating autologous stem cell boost (auto-SCB) for chimeric antigen receptor T-cell (CAR T)-related hematologic toxicity in adults with relapsed/refractory multiple myeloma (RRMM), were published in Blood Cancer Journal by Varga et al. Outcomes were compared between patients with prolonged cytopenias receiving SCB within 1 year of CAR T-cell infusion (n = 39) and matched controls receiving supportive care (no SCB; n = 52). 

Key data: Auto-SCB led to hematologic recovery in 97.4% of patients, with a median time to recovery of 24 days. At Day 90, SCB patients had higher median hemoglobin (10.6 vs 8.7 g/dL; p = 0.002) and platelet counts (135 vs 35 K/µL; p < 0.001) vs non-SCB controls. Median progression-free survival (PFS) was 11.0 months with SCB vs 8.2 months with no SCB, while median overall survival (OS) was not reached (NR) and 12.3 months, respectively. No new toxicities were attributed to SCB.

Key learning: Auto-SCB was shown to be a well-tolerated and effective strategy to promote hematologic recovery in patients with RRMM experiencing prolonged cytopenias after CAR T-cell therapy, supporting its consideration as a supportive strategy for selected patients.