HOLLYWOOD, FLA. – New data have led to upgrades of two rituximab regimens and radioimmunotherapy for follicular lymphoma in the National Comprehensive Cancer Network’s clinical practice guidelines for non-Hodgkin’s lymphoma.
Other changes include a section that addresses the utility of positron emission tomography in the assessment of follicular lymphoma and the addition of recommendations for the evaluation and management of posttransplant lymphoproliferative disorder (PTLD), according to Dr. Andrew D. Zelenetz of Memorial Sloan-Kettering Cancer Center in New York.
At the National Comprehensive Cancer Network’s annual conference on clinical practice guidelines, he reported updates in the following areas on behalf of the NCCN’s 30-member panel on non-Hodgkin’s lymphoma:
Rituximab plus bendamustine. The combination of rituximab (Rituxan) plus bendamustine (Treanda) has been upgraded from a category 2A to a category 1 recommendation for first-line treatment of follicular lymphoma, a common form of NHL, Dr. Zelenetz announced.
The most widely used first-line regimen for follicular lymphoma has been R-CHOP (a combination of rituximab, cyclophosphamide, doxorubicin HCl, vincristine sulfate, and prednisone). In a study presented in 2009 at the American Society of Hematology (ASH) annual meeting comparing the efficacy of the R-CHOP protocol with that of the rituximab-bendamustine (RB) combination, the complete remission rate among patients randomized to RB treatment was 73% vs. 39.6% in the R-CHOP arm, Dr. Zelenetz said (Blood [ASH Annual Meeting Abstracts] 2009 Nov.;114:405).
"The median progression-free survival was also higher [in the RB group], at 54.9 months compared with 34.8 months [in the R-CHOP arm]," a finding that he described as unexpected. "This study was designed as an equivalency study, and it certainly surprised many of us that rituximab-bendamustine was significantly better in terms of progression-free survival," he said.
Although there was no difference in overall survival between the two groups, he noted, the RB protocol was better tolerated with less hematologic toxicity and no alopecia.
Rituximab maintenance and radioimmunotherapy. The panel also upgraded rituximab maintenance and chemotherapy followed by radioimmunotherapy from a category 2B to a category 1 recommendation for the treatment of follicular lymphoma after the first remission. The guideline change regarding postremission management was sparked by the results of two recent studies, Dr. Zelenetz said.
The first demonstrated a significant reduction in the risk of recurrence among patients who received rituximab maintenance after responding to induction with rituximab plus chemotherapy (Lancet 2011;377:42-51). The other, presented at the 2010 ASH meeting, showed that postremission radioimmunotherapy following chemotherapy significantly improved the complete response and progression-free survival rates relative to the experience in patients who received no additional treatment following remission (Blood [ASH Annual Meeting Abstracts] 2010 Nov.;116:594).
"Unfortunately, neither study was associated with improvement in overall survival," he said.
PET imaging. In the assessment of follicular lymphoma, "studies have shown that PET imaging can be used to distinguish between indolent and aggressive lymphoma and can help guide the site for optimal biopsy, "especially in patients in whom there is a concern about transformation from indolent to aggressive disease," Dr. Zelenetz said. While it cannot replace biopsy, "[PET imaging] can help identify the best vs. the most convenient lymph node to biopsy," he said(J. Clin. Oncol. 2005;23:4643-51; Ann. Oncol. 2009; 20:508-12).
In addition, PET–computed tomography (PET-CT) has a role in the assessment of treatment response because "the predictive power of posttreatment PET-CT is stronger than other prognostic factors," Dr. Zelenetz explained.
Posttransplant lymphoproliferative disorder. PTLD "has emerged as a significant complication of solid organ and allogeneic bone marrow transplantation," according to Dr. Zelenetz.
The revised guidelines recommend outlining the procedure for establishing a diagnosis based on histology and immunophenotype, and categorizes relevant tests as essential or useful under certain circumstances. Among information deemed "essential," he said, is the determination of patients’ Epstein Barr virus (EBV) status, as well as their histopathology (polymorphic or monomorphic cells) and immunophenotype.
NCCN recommendations include reducing immunosuppression for patients with early lesions, which are usually associated with Epstein-Barr virus, and for those with polymorphic systemic and monomorphic disease. Treatment may include antiviral prophylaxis with gancyclovir (Cytovene), rituximab, or chemoimmunotherapy, depending on PTLD subtype, said Dr. Zelenetz, noting that "stem cell transplantation is usually reserved for relapse or refractory situations, as we would manage other aggressive lymphomas."
Dr. Zelenetz disclosed receiving grant and research support from companies including Amgen Inc., Celgene Corp., Cell Therapeutics Inc., Cephalon Inc., Genentech Inc., GlaxoSmithKline, and Sanofi-Aventis US.