Phase II Study of Bortezomib in Combination with Cyclophosphamide and Rituximab for Relapsed or Refractory Mantle Cell Lymphoma.

BACKGROUND: Relapsed or refractory mantle cell lymphoma (MCL) has a poor prognosis. The best outcome is achieved in patients who have a partial or complete response to salvage treatment and proceed to allogeneic stem cell transplant.

PATIENTS AND METHODS: Twenty-one patients were given a combination regimen of bortezomib, cyclophosphamide, and rituximab at MD Anderson Cancer Center as part of a single-arm, prospective, open-label phase II clinical trial. The median age was 66 years, with a median number of prior treatments of three. Sixty-seven percent had failed intensive chemoimmunotherapy and 43% were intermediate/high risk according to the MCL international prognostic index score, with a median Ki-67 proliferation index of 45% in those who were tested.

RESULTS: The rates of overall and complete response achieved were 74% and 42%, respectively, with median progression-free and overall survivals of 9 months and 36.4 months, respectively. The regimen's toxicity profile was acceptable; only 25% of the cycles resulted in grade 3 or 4 neutropenia or thrombocytopenia, and only 3% of cycles produced grade 3-4 fatigue. There were no episodes of grade 3-4 neuropathy.

CONCLUSION: The combination of bortezomib with cyclophosphamide and rituximab is an effective and well-tolerated regimen in patients with relapsed/refractory MCL. Because of its low toxicity, future combinations of this regimen with other promising drugs that have different mechanisms of action offer a realistic possibility that may improve outcomes for patients who have MCL. The Oncologist 2017;22:549-553 IMPLICATIONS FOR PRACTICE: The combination of bortezomib with cyclophosphamide and rituximab represents an additional effective novel salvage regimen for mantle cell lymphoma. This combination adds to the growing list of treatment options available for patients with mantle cell lymphoma.