Long-Term Outcomes of Early Rituximab Monotherapy versus Watchful Waiting in Follicular Lymphoma
Introduction
Rituximab is an anti-CD20 monoclonal antibody, has established efficacy against follicular lymphoma (FL), with less toxicity than chemotherapy.
Aim
To evaluate early rituximab monotherapy’s impact on time to initiation of new treatment, overall survival, and transformation risk in asymptomatic FL patients.
Patient Profile
Adult patients with asymptomatic, stage II–IV, grade 1–3a low tumour burden FL and Eastern Cooperative Oncology Group performance status 0–1
Methods
- Study design: Open label, randomised, phase 3 trial
- Median follow-up was 14·7 years
- Study Endpoint
- Primary endpoint was time to initiate new treatment (TTNT) defined as the time from randomization until the first day systemic chemotherapy or radiotherapy was given.
- Secondary endpoints were TT2NT, overall survival, cause-specific mortality, and response and spontaneous remission rate.
Results
- Rituximab maintenance significantly delayed the need for new treatment.
- At 15 yrs, 65% of patients in the rituximab maintenance group had not started new treatment compared to 48% in the induction group and 34% in the watchful waiting group.
Table 1: Treatment outcomes
|
Outcome |
Watchful Waiting |
Rituximab Induction |
Rituximab Maintenance |
|
TTNT Median |
5.6 yrs |
14.8 yrs |
Not reached (15.6 yrs - not estimable) |
|
15-yr No New Treatment (%) |
34% |
48% |
65% |
|
Overall Survival (15-yr) |
68% |
66% |
73% |
|
High-grade Transformation (15-yr) |
20% |
15% |
17% |
|
Second New Treatment (%) |
18% |
15% |
11% |
|
Second Primary Malignancy |
20% |
23% |
21% |
Figure 1: Percentage of Patients not started new treatment after 15-yr follow-up
- Overall Survival: 15-year overall survival was 73% for rituximab maintenance, 66% for rituximab induction, and 68% for watchful waiting. No significant differences in overall survival were found between groups.
- Transformation Risk was similar across groups (15–20%)
- Cause-Specific Mortality: The 15-year incidence of lymphoma-related death was 12% for rituximab maintenance, 18% for rituximab induction & 14% for watchful waiting. No significant differences were observed.
- TT2NT: No significant differences in TT2NT were observed between groups.
- Second Primary Malignancy: Occurred in 20% of patients overall, with no significant differences between groups.
- 23% for watchful waiting
- 21% for rituximab induction
- 16% for rituximab maintenance
Conclusion
- Early rituximab monotherapy significantly prolongs TTNT in patients with advanced stage, asymptomatic low tumour burden FL and should be considered on an individual patient basis.
- It offers a non-toxic option to delay or avoid chemotherapy, without compromising survival or transformation risk.
Reference
Lancet Haematol 2025;12: e335–45.
