Allogeneic stem cell transplantation (allo-HSCT) appears to be an effective strategy for inducing durable remission among patients with relapsed or refractory primary mediastinal B-cell lymphoma (R/R PMBCL), according to research published in Acta Oncologica.
There is limited data regarding the optimal PMBCL treatment strategy, primarily because few large clinical trials have been conducted. Although rituximab has improved outcomes in the first therapy line, up to 30% of patients with PMBCL have a relapse or are refractory to treatment. Further strategies, such as autologous HSCT, are used in the second line, though data suggest outcomes are not optimal in the R/R PMBCL patient population.
Previous study has suggested, however, that allo-HSCT may be curative after autologous HSCT. For this study, researchers evaluated outcomes among patients with R/R PMBCL who undergo allo-HSCT.
Overall, data from 33 patients were included. The median patient age at transplant was 33 years (age, 18-61), 42% of patients were male sex, and 43.4% of patients had Ann Arbor stage I or II disease. The median number of prior therapy lines, furthermore, was 3; 42% percent of donors were patients’ siblings, while 39% were matched related.
The median follow-up for living patients was 78 months. Analysis showed that the median 2-year overall, progression-free, and graft vs host disease-free/relapse-free survival rates were 48% (95% CI, 33-70), 47% (95% CI, 33-68), and 38.5% (95% CI, 25-60), respectively, in the overall cohort.
The overall relapse and nonrelapse mortality rates, furthermore, were 34% and 18%, respectively.
Further analysis suggested that the only predictor of 2-year progression-free or overall survival rates was disease status at transplant (hazard ratios, 6.12 and 7.04, respectively; both P <.05).
There were 10 patients who were alive at 4 years’ follow-up, suggesting the possibility of a cure for nearly one-third of patients who undergo allo-HSCT.
“Although this study is retrospective series, it has included a significant number of patients suffering from this rare condition,” the authors wrote in their report. “It provided encouraging results suggesting that allo-HSCT should be considered in patients with R/ R PMBCL who achieve at least a [partial response] after salvage therapy.”
Le Calvez B, Tessoullin B, Renaud L, et al. Outcomes after allogeneic hematopoietic stem cell transplantation for adults with primary mediastinal B cell lymphoma: a SFGM-TC and LYSA study. Acta Oncol. Published online October 10, 2022. doi:10.1080/0284186X.2022.2130709