The research team, headed by Thomas Habermann, M.D., of the Eastern Cooperative Oncology Group, Boston, Mass., concluded that the addition of rituximab to the CHOP regimen as a first-line treatment did not influence overall response rates or early progression in patients.
Overall response rates achieved were 77 percent with R-CHOP versus 76 percent with CHOP alone. Progressive disease during treatment occurred in 6.5 percent of patients on R-CHOP versus 10.5 percent on CHOP alone. With a median follow-up of 2.7 years, the time-to-treatment failure (TTF) favored R-CHOP for induction, but there was no difference in overall survival.
Researchers randomized 632 patients with diffuse large B-cell lymphoma (DLBCL), median age 69 years, to either R-CHOP (318 patients) [administered as cyclophosphamide 750 mg/m2 IV day 1; doxorubicin 50 mg/m2 IV day 1; vincristine 1.4 mg/m2 (maximum dose=2) day 1; prednisone 100 mg/m2 days one to five; rituximab 375 mg/m2 day seven, three and two days before cycles three, five, and seven] or CHOP (314 patients) [two cycles beyond complete remission (total six to eight cycles)]. Researchers further randomized patients who achieved either complete or partial response to maintenance rituximab (207 patients; 375 mg/m2 weekly for four weeks repeated every six months times four) versus observation (208 patients). Patients who were included in the results were 540 for induction (initial) therapy and 348 for maintenance.
At six months, and prior to the second randomization, the TTF failure rates were 15 percent for R-CHOP and 17 percent for CHOP. TTF also favored maintenance rituximab, but there was no difference in overall survival. For patients treated with R-CHOP, there was no significant difference seen in maintenance rituximab versus observation in either TTF or overall survival. Conversely, CHOP patients had a significantly longer TTP with maintenance rituximab but no statistically significant prolongation in overall survival.
"Nearly half of patients with diffuse large B-cell lymphoma can be successfully treated with therapy," said Ronald Hoffman, M.D., President of the American Society of Hematology. "Therefore, it is important to identify whether the addition of new treatments, such as rituximab, to the current standard regimen has added benefit. It is the goal of hematologists to treat our patients with the best available treatments, with the least amount of drugs necessary."
Approximately 31 percent of all lymphomas are diffuse large B-cell lymphoma (DLBCL), according to the American Cancer Society. DLBCL is a fast growing lymphoma, whose usual symptoms are a quickly growing mass in the body or in a lymph node that patients can feel. Although it usually starts in lymph nodes, DLBCL can grow in other areas, such as the bones, the brain, or the spinal cord. About one-third of these lymphomas are confined to one part of the body. When it is confined, DLBCL is considered to be more curable than when it has spread to other parts of the body. DLBCL can affect any age group but occurs mostly in older people, with an average age in the mid-60s. Approximately 50 percent of people with this lymphoma are cured with therapy.
The American Society of Hematology is the world's largest professional society concerned with the causes and treatment of blood disorders. Its mission is to further the understanding, diagnosis, treatment, and prevention of disorders affecting blood, bone marrow, and the immunologic, hemostatic, and vascular systems, by promoting research, clinical care, education, training, and advocacy in hematology.