This post-hoc subanalysis of the LYM-3002 phase 3 study assessed the efficacy and safety of substituting vincristine in rituximab, cyclophosphamide, doxorubicin and prednisone (R-CHOP; n=42) for bortezomib (VR-CAP; n=38) in a subgroup of 80 mantle cell lymphoma (MCL) patients aged<60 years who did not receive stem cell transplantation (SCT) despite medical eligibility. Complete response (CR)/unconfirmed CR (CRu) rates were 67 vs. 39% (odds ratio 3.69 [95% CI(confidence interval): 1.31, 10.41]; p=.012).
After 40 months median follow-up, median progression-free survival by independent radiology committee with VR-CAP vs. R-CHOP was 32.6 vs. 12.0 months (hazard ratio (HR) 0.59 [95% CI: 0.31, 1.13]; p=.108); median overall survival was not reached vs. 47.3 months (HR 0.81 [95% CI: 0.33, 1.96]; p=.634).
Adverse events included neutropenia (92/76%), thrombocytopenia (70/10%) and leukopenia (65/50%). VR-CAP represents a potential alternative to R-CHOP in combined and/or alternating regimens for younger, SCT-eligible MCL patients.