Primary mediastinal B-cell lymphoma (PMBCL) is a rare form of large B-cell lymphoma (LBCL) with around 90% of patients cured with frontline treatment. For relapsed or refractory (R/R) disease, the optimal treatment is unclear. CD19 chimeric antigen receptor-T cell (CAR-T) has been established as the preferred second line (2L) treatment for primary refractory or early relapsing LBCL based on the overall survival benefits observed in the landmark phase III trials. However, PMBCL patients were underrepresented on these pivotal studies. This study evaluated outcomes of 252 patients treated with 2L therapies for R/R PMBCL at 14 US institutions between 2001 and 2025. Platinum-based salvage with intent to proceed to high dose therapy and autologous stem cell transplant (HDT/ASCT) (platinum cohort) and CD19 CAR-T (CAR-T cohort) were given as 2L therapy in the real-world setting in 157 and 26 patients, respectively. Overall response rate (ORR), complete response (CR) rate and median progression-free survival (PFS) were significantly higher in the CAR-T cohort compared with the platinum cohort (ORR: 91.3% vs 44.2%, p <0.001; CR 65.2% vs 14.7%, p<0.001; median PFS not reached vs 3.5 months, hazard ratio (HR) 0.28, 95% CI 0.15-0.54, p=0.001). No significant difference was observed in overall survival. This study demonstrated superior response rate and PFS of CD19 CAR-T over platinum-based salvage with intent to proceed to HDT/ASCT as 2L treatment for R/R PMBCL.
Intensive induction regimens after deferring initial therapy for mantle cell lymphoma are not associated with improved survival
AbstractIntroductionWhile most patients with mantle cell lymphoma (MCL) receive therapy shortly after diagnosis, a subset of patients with indolent‐behaving disease can safely defer treatment. In this subgroup, we evaluated the importance of treatment intensity in patients with MCL who defer initial therapy.MethodsOut of 1134 patients with MCL from 12 academic centers, we analyzed 219 patients who initiated therapy at least 90 days after diagnosis. Patients who received induction with high‐dose cytarabine and/or autologous stem cell transplantation (ASCT) in first remission were considered to have received intensive therapy (n = 88) while all other approaches were non‐intensive (n = 131).ResultsThere was no difference in progression‐free (PFS; P = .224) or overall survival (OS; P = .167) in deferred patients who received non‐intensive vs. intensive therapy. Additionally, univariate and multivariate Cox proportional hazards models were performed for PFS and OS. Treatment at an academic center (HR 0.43, P = .015) was associated with improved OS in both univariate and multivariate models, while intensity of treatment was not associated with improved OS in either model.ConclusionsThese results indicate that intensified initial treatment is not associated with improved survival after deferring initial therapy, although prospective studies are needed to determine which of these patients with MCL may benefit from intensive therapy.