Rituximab Post-transplant Improves Survival in B-Cell NHL

ORLANDO—Giving rituximab (Rituxan) after high-dose chemotherapy/autologous peripheral blood stem cell transplantation for B-cell non-Hodgkin’s lymphoma (NHL) produced better survival and freedom from progression rates than would be expected with a conventional transplant regimen, according to a phase II study reported at the 43rd Annual Meeting of the American Society of Hematology (abstract 3578).

The rationale for the study was the 40% to 60% relapse rate among patients receiving high-dose therapy/stem cell transplant, said Steven M. Horwitz, MD, of Stanford University. Since most B-cell NHL patients express the CD20 antigen, rituximab was considered an excellent candidate for adjuvant therapy in the post-transplant setting.

Study Design

The study involved 35 patients with B-cell NHL undergoing high-dose therapy/transplant. Most patients (25) had diffuse large cell NHL, but 3 had mantle cell lymphoma, 3 had transformation of low-grade lymphoma, and 4 had other B-cell lymphomas.

As a preparative regimen, 32 patients received carmustine (BiCNU), cyclophosphamide, and etoposide, and 3 had total-body irradiation. All received a purged stem cell product.

The first four patients received four weekly transfusions of rituximab at a dose of 375 mg/m² starting 40 days after transplant. The other 31 patients received that plus an additional 4-week course of rituximab at 6 months.

Among the 35 patients enrolled, 29 completed all planned therapy. Six patients received less rituximab than planned due to neutropenia, hypotension, disseminated zoster, relapse, or death. At a median follow-up of 18 months, four patients had died and four had relapsed.

The most common toxicity was grade 3-4 neutropenia, with 19 patients experiencing a total of 46 episodes. All patients recovered. Other toxicities included carmustine pneumonitis in eight patients, herpetic infection in seven, respiratory infection in four, pleural effusion in one, thrombocytopenia in one, and syncope in one. By 12 months, B-cell recovery had not occurred in any of the evaluable patients.

Estimated 2-year overall survival was 88% and freedom from progression was 87%. Both these rates were higher than would be expected with a conventional transplant regimen, he said.

"Ultimately, these results need to be confirmed by a larger study," Dr. Horwitz said. He noted that an intergroup randomized trial is under development to further evaluate the possible benefits of adding rituximab to high-dose therapy with stem cell rescue.