The combination of so-called “Boom Boom” radiotherapy prior to treatment with lisocabtagene maraleucel (liso-cel) was found to be safe, feasible, and effective, according to an investigator-initiated study led by Christopher D’Angelo, MD, of the University of Nebraska Medical Center. The data were presented during the 2025 International Conference on Malignant Lymphoma (ICML) in Lugano, Switzerland.
The study enrolled adults with relapsed or refractory aggressive B-cell non-Hodgkin lymphoma who received low-dose radiotherapy—referred to as Boom Boom RT—to disease sites seven to 10 days before infusion of liso-cel, without any other bridging therapy except for steroids. Boom Boom RT consists of 4 Gy delivered in two 2-Gy fractions, a low-dose regimen previously shown to be effective in indolent lymphomas.
“These data suggest that the use of low-dose RT as bridging therapy is safe, feasible, and may be effective at enhancing outcomes to liso-cel therapy,” D’Angelo and colleagues wrote.
Early results showed a complete response rate exceeding 80% in a high-risk patient population, suggesting that low-dose radiotherapy can potentially serve as a bridge to CAR T-cell therapy and augment its efficacy.
The study enrolled 32 patients with aggressive B-cell non-Hodgkin lymphoma, of whom 30 (94%) received Boom Boom RT and liso-cel, meeting the feasibility threshold. The median age was 70, and 69% were male. Most had DLBCL, and 50% were refractory to frontline therapy. Among 29 evaluable patients, the overall response rate was 86%, with a complete response rate of 83%. Two patients had stable disease, and two had progression as best response. At 200 days, patients who achieved a CR had a PFS rate of 75% and an OS rate of 89%.
Researchers continue to investigate how low-dose radiation may help “prime” the immune response ahead of cellular therapy.
Funding for the study was provided by Bristol Myers Squibb.
Reference
D’Angelo C, Enke C, Vose J. Boom Boom radiation prior to lisocabtagene maraleucel is feasible and contributes to high complete response rates for aggressive B-cell non-Hodgkin lymphoma. ICML. Lugano, Switzerland.
