Management of indolent lymphoma: where are we now and where are we going

Indolent lymphoma comprises a unique and challenging subset of non-Hodgkin lymphoma (NHL). While definitions of indolence will vary, the most common indolent NHL subtypes include follicular lymphoma, marginal zone lymphoma, and small lymphocytic lymphoma. Patients with indolent NHL (iNHL) excluding those with rare localized presentations are often met with an incurable but highly treatable NHL. In the rituximab era, response rates are approaching 90% with rituximab plus chemotherapy and time to next treatment are beginning to be measured in years. As a result of a prolonged natural history, we are encountering a gridlock of novel regimens and agents that appropriately fill peer-reviewed journals. In this review, we tackle a spectrum of topics in the management of indolent lymphoma including the initial approach to the newly diagnosed patient, approaches to first cytotoxic chemotherapy, maintenance and consolidation techniques, as well as highlight promising treatments on the horizon in iNHL. Clinicians continue to face tough choices in the management of iNHL. Through well-thought out clinical trials and peer-reviewed vetting of data we will continue to determine how to best manage the clinical continuum that is iNHL.

Bendamustine: safety and efficacy in the management of indolent non-hodgkins lymphoma

Bendamustine (Treanda, Ribomustin) was recently approved by the US Food and Drug Administration (FDA) for treatment of patients with rituximab refractory indolent lymphoma and is expected to turn into a frontline therapy option for indolent lymphoma. This compound with amphoteric properties was designed in the former Germany Democratic Republic in 1960s and re-discovered in 1990s with multiple successive well-designed studies. Bendamustine possesses a unique mechanism of action with potential antimetabolite properties, and only partial cross-resistance with other alkylators. Used in combination with rituximab in vitro, bendamustine shows synergistic effects against various leukemia and lymphoma cell lines. In clinical studies, bendamustine plus rituximab is highly effective in patients with relapsed-refractory indolent lymphoma, inducing remissions in 90% or more and a median progression-free survival of 23-24 months. The optimal dosing and schedule of bendamustine administration is largely undecided and varies among studies. Results of ongoing trials and dose-finding studies will help to further help ascertain the optimal place of bendamustine in the management of indolent NHL.

Phase I trial of weekly and twice-weekly bortezomib with rituximab, cyclophosphamide, and prednisone in relapsed or refractory non-Hodgkin lymphoma

PURPOSE

To determine the safety and efficacy of substituting weekly or twice-weekly bortezomib for vincristine in the R-CVP (rituximab, cyclophosphamide, vincristine, and prednisone) regimen in patients with relapsed/refractory indolent and mantle cell lymphoma (MCL).

EXPERIMENTAL DESIGN

Of the 57 patients in this phase I trial, 55 participated in 1 of 2 dosing schedules that included rituximab (375 mg/m(2)) and cyclophosphamide (750 or 1,000 mg/m(2)) administered on day 1 of each 21-day cycle and prednisone (100 mg orally) days 2 to 6. In the once-weekly schedule, bortezomib was administered on days 2 and 8; on the twice-weekly schedule, bortezomib was given on days 2, 5, 9, and 12. Bortezomib and cyclophosphamide were alternately escalated. A separate cohort of 10 patients in the twice-weekly schedule received concurrent pegfilgrastim (PegG) on day 2.

RESULTS

Both schedules of R-CBorP (rituximab, cyclophosphamide, bortezomib, and prednisone) were well tolerated. Most toxicities across all dose levels and cycles were grade 1 or 2. The overall response rates for patients on the weekly (n = 13) and twice-weekly (n = 33) schedules were 46% [23% complete response/complete response unconfirmed (CR/CRu)] and 64% (36% CR/CRu), respectively. Concurrent PegG did not increase hematologic toxicities in this regimen. A randomized phase II study is under way to further compare toxicity and efficacy of the 2 dosing schedules.

CONCLUSIONS

R-CBorP is a safe and effective regimen in patients with relapsed/refractory indolent and MCLs. Most toxicities were grade 1 or 2, and a promising response rate was seen in this phase I study.