Bortezomib added to an alternating chemoimmunotherapy regimen did not improve time to treatment failure in patients with newly diagnosed mantle cell lymphoma (MCL), results of a phase 2 study have suggested.
Response rates and time to treatment failure were similar to what has been seen historically without the addition of bortezomib, according to study investigator Jorge E. Romaguera, MD, of the University of Texas MD Anderson Cancer Center, Houston, and his colleagues.
The phase 2 study included 95 patients with newly diagnosed MCL treated with alternating cycles of bortezomib added to rituximab plus hyperfractionated cyclophosphamide, vincristine, doxorubicin, and dexamethasone (BzR-hyperCVAD) and bortezomib added to rituximab plus high-dose methotrexate and high-dose cytarabine (BzR-MA).
Of 87 patients evaluable for response, alternating BzR-hyperCVAD/BzR-MA resulted in an overall response rate of 100% and a complete response rate of 82%, Dr. Romaguera and his colleagues reported in the journal Cancer. At a median follow-up of 44 months, median time to treatment failure was 55 months, and median overall survival had not yet been reached, according to the report.
Dr. Romaguera and his coauthors compared these results with those from a previous study of alternating R-hyperCVAD/R-MA, in which the median time to treatment failure was 56.4 months. “This suggests that the addition of bortezomib does not improve the outcome,” they wrote in the current report.
Although more follow-up is needed, the landscape of MCL treatment is changing quickly, they added. In particular, lenalidomide and ibrutinib, already approved for relapsed/refractory MCL, are now being evaluated as part of first-line MCL regimens. “These drugs will offer strategies of either consolidation or maintenance after induction and will hopefully help continue to improve the duration of the initial response and the overall outcome,” the researchers wrote.
In the current phase 2 study, the fact that 100% of patients achieved complete response suggested that relapses come from minimal residual disease, which “has clearly become a clinical factor for the outcomes of patients with MCL and will likely become the next endpoint,” they wrote.
The researchers reported having no financial disclosures related to the study, which was supported by Takeda Oncology.
SOURCE: Romaguera JE et al. Cancer. 2018 May 3. doi: 10.1002/cncr.31361.