Rituxan Delays Disease Progression in Indolent Non- Hodgkin’s Lymphoma

Genentech Inc, Idec Pharmaceuticals, and Roche recently announced the initial results of a randomized multicenter study of extended therapy with single-agent rituxan (Rituximab) in patients with chemotherapy-naive and relapsed indolent non-Hodgkin’s lymphoma (NHL). Professor Michele Ghielmini of the Swiss Group for Clinical Cancer Research discussed the results at the Eighth International Conference on Malignant Lymphoma.

Study Design

The study enrolled 188 patients. At study entry, 59 patients had received noprior therapy, and 129 had received some form of prior chemotherapy for theirNHL. All patients received an induction course of rituxan (375 mg/m²/wk for 4weeks). The overall response rate was 66% (39/59 patients) in chemotherapy-naivepatients and 46% (59/129) in those with relapsed disease.

At week 12, 151 of the 188 patients (80%) who achieved either a complete orpartial response or experienced stable disease with the initial course ofrituxan were randomized to receive extended therapy with rituxan (one dose of375 mg/m² at months 3, 5, 7, and 9, for a total of four doses) or no treatmentand observation.

Event-Free Survival End Point

After a median follow-up of 25 months, the primary end point of event-freesurvival was 22.4 months in patients receiving extended therapy (n = 73)compared to 13.6 months in the observation-only arm (n = 78). Inchemotherapy-naive patients, the event-free survival was 35.6 months in theextended rituxan therapy arm, compared to 18.3 months for patients in theobservation-only arm.

According to the authors, there was no clinically significant increase inadverse events or infections in patients receiving extended rituxan therapycompared to the observation control arm.

"For this patient group, the risk of relapse is extremely high and witheach successive relapse, the duration of remission decreases," saidProfessor Ghielmini. "Clearly, the results of this study are encouragingfor people with this form of non-Hodgkin’s lymphoma."

Adverse Events

The majority of patients experience infusion-related symptoms with theirfirst infusion of rituxan. These include but are not limited to flu-like fever,chills/rigors, nausea, urticaria, headache, bronchospasm, angioedema, andhypotension. These symptoms vary in severity and generally are reversible withmedical intervention.

Severe and fatal infusion-related reactions have occurred rarely and almostalways have been associated with the first infusion of rituxan. Severemucocutaneous skin reactions have also occurred rarely with rituxan therapy.Many of these reactions have been described as paraneoplastic pemphigus and areknown to be associated with B-cell lymphomas.