Is bortezomib combined with rituximab and dexamethasone effective in relapsed-refractory mantle cell lymphoma?

This study examined the effectiveness of the combination bortezomib, rituximab, and dexamethasone (BORID) in patients with relapsed or refractory (did not respond to treatment) mantle cell lymphoma. This study concluded that this combination was effective and tolerable in these heavily pretreated patients.

Mantle cell lymphoma (MCL) is an aggressive and hard to treat type of non-Hodgkin lymphoma. Intense treatments, such as high-dose chemotherapy and stem cell (immature blood cell) transplantation may be effective, but many patients cannot tolerate this intensity. This includes patients with other medical conditions or older patients.

Bortezomib is a proteasome inhibitor. The proteasome is a molecule involved in cell growth and death. Blocking the proteasome can decrease cancer cell growth and increase cancer cell death. Previous studies have shown bortezomib to be effective as a single therapy in MCL. It is not clear whether it is safe and effective when combined with other common MCL treatments, such as rituximab and dexamethasone (BORID).

This study examined the safety and effectiveness of the BORID combination. Sixteen patients with relapsed/refractory MCL were included. All patients had been previously treated with the chemotherapy combination CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisone). 88% had been previously treated with rituximab. 31% had undergone stem cell transplantation.

BORID treatment led to an 81.3% overall response rate. There was a complete remission (CR, no sign of disease) in 43.8%. There was a partial response (decreased cancer activity) in 37.5%. Average time to disease progression was 12.1 months. Average overall survival (time from treatment until death from any cause) was 38.7 months. CR was associated with longer times to disease progression. Five patients were still in CR after 48 months.

The most common severe side effects were low platelet (blood cells involved in clotting) levels in 37.5% and fatigue in 18.8%. Patients also experienced peripheral neuropathy (nerve pain in the hands or feet, 12.5%) and low blood sodium levels (12.5%). Non-severe side effects included infections (43.8%), peripheral neuropathy (43.8%), fatigue (25%), diarrhea (25%), and rash (18.8%).

This study concluded that BORID was safe and effective in heavily pretreated relapsed/refractory MCL.