There is no standard treatment of stage III-IV follicular lymphoma patients with a low-tumor burden. Rituximab(Drug information on rituximab) (Rituxan), a chimeric anti-CD20 antibody, is active in pretreated patients with an overall response (OR) rate of 50% and good tolerance.
We treated patients with good-prognosis follicular lymphoma with the following goals: (1) to evaluate the clinical and molecular efficacy of rituximab in previously untreated patients; and (2) to follow patients in complete molecular remission so as to establish relationships between clinical response and molecular remission. Criteria for inclusion after consent were: a diagnosis of follicular lymphoma (pathology review); age between 18 to 75 years; stage II-IV disease; performance status (PS) 0-1, measurable disease, and the absence of the following criteria: B symptoms, tumor mass > 7 cm, compression, increased serum lactate dehydrogenase (LDH) or beta-2-microglobulin.
Patients were treated with four weekly infusions of rituximab at a dose of 375 mg/m². Polymerase chain reaction (PCR) assays for bcl-2-JH rearrangement (MBR and mcr primers) on blood and bone marrow were performed before treatment and 1, 6, and 12 months after treatment. Among 50 patients included, 52% were males, 92% were PS = 0, 92% were stage III-IV, and 66% had marrow involvement.
The OR rate was 69% with 31% complete responses (CR), 10% unconfirmed CR, and 28% partial responses (PR), according to the criteria of Cheson and coworkers. After a median follow-up of 13 months, 22% of patients have progressed (9% of responders). Of 32 patients who were PCR positive before treatment, 17 (57%) became negative after treatment with rituximab. Of the latter patients, 12 were analyzed after 12 months, and 10 remained PCR negative. Molecular remission was strongly associated with clinical response and absence of progression. Only two transient grade 3 infusion-related toxicities were observed.
CONCLUSION: Rituximab has high efficacy and low toxicity in previously untreated patients with lowtumor burden follicular lymphoma. In addition, it induces complete molecular remission in > 50% of evaluable patients and, thus, may represent a curative approach.