The combination of bortezomib, cladribine, and rituximab (VCR) was an effective treatment regimen for patients with CD20-positive mantle cell lymphoma (MCL) and indolent non-Hodgkin’s lymphoma (iNHL), based on results of a recent phase 2, open-label study.
The overall response rate was 92% in the single-center, 24-patient study. The 2-year progression-free survival (PFS) was 82% and 54%, respectively, for MCL and iNHL patients; PFS was 80% for treatment-naive patients and 57% for those with refractory/recalcitrant disease, according to Soham D. Puvvada, MD, of the University of Arizona Cancer Center in Tucson, and her associates.
Two-year overall survival was 91% for MCL and 69% for iNHL patients. Median time to progression was 34.5 months, and median PFS had not been reached at 2 years, according to the researchers.
While the study () was small and limited by its single-center design, the VCR combination “has encouraging activity in both MCL and iNHL and could be compared to standard therapies in future studies,” the researchers wrote. “For MCL in particular, we believe a noninferiority comparison to standard therapies would be justified by our results.”
Adverse events were most commonly hematologic, and three patients experienced febrile neutropenia, data show.
“Although hematological toxicity can be an issue, the regimen provides an alternative option in transplant ineligible relapsed/refractory MCL and iNHL,” wrote Dr. Puvvada and her colleagues. The study was published in Clinical Lymphoma, Myeloma & Leukemia (doi:).
The researchers studied the combination of bortezomib, the proteasome inhibitor initially approved for relapsed/refractory MCL, cladribine, which has shown activity and promising response rates in patients with indolent lymphomas, and rituximab in patients with CD20-positive mantle cell or indolent lymphoma.
Patients with follicular lymphomas were eligible to be included in the study if they had received at least one previous line of therapy. All other participants could be treatment naive or have relapsed after previous treatment.
Of the 24 patients enrolled, 11 had MCL, 5 had follicular lymphoma, 4 had marginal zone lymphoma, 3 had lymphoplasmacytic lymphoma, and 1 had small lymphocytic lymphoma.
The VCR regimen, given every 28 days for no more than six cycles, included rituximab at 375 mg/m2 given intravenously on day 1 of each cycle, cladribine 4 mg/m2 given intravenously over 2 hours on days 1 through 5, and bortezomib 1.3 mg/m2 given intravenously on days 1 and 4. Patients received a median of five cycles of therapy.
Adverse events of grade 3 or greater occurred in 14 patients (58%); 8 patients had leukopenia, 6 had thrombocytopenia, 5 had fatigue, and 5 had neutropenia, which included febrile neutropenia in 3 patients.
With a median follow-up of 38.5 months, overall response rate for VCR was 96%. Complete responses occurred in 8 of 23 evaluable patients (35%) and partial responses in 14 more patients (61%).