# PRIMA

Source: https://onco.cc/trials/prima-follicular/  
OnCo record `prima-follicular` (Trial). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

Two years of an antibody given every two months after chemotherapy more than doubled the time before follicular lymphoma came back, but after nine years the two groups were equally likely to be alive.

## Summary

PRIMA is the trial that made rituximab maintenance a routine offer in follicular lymphoma, and the trial that shows most clearly why a progression-free survival benefit is not the same as a survival benefit. It ran at 223 centres in 25 countries. Patients with previously untreated high tumour burden follicular lymphoma received one of three immunochemotherapy induction regimens in routine use; the 1,018 who reached a complete or partial response were randomised to rituximab 375 mg per square metre every eight weeks for two years, or to observation.

The first report, at a median follow-up of 36 months, gave three-year progression-free survival of 74.9 per cent with maintenance against 57.6 per cent with observation (hazard ratio 0.55, 95 per cent confidence interval 0.44 to 0.68). The final report, after nine years, kept the effect: median progression-free survival 10.5 years against 4.1 years (hazard ratio 0.61, 0.52 to 0.73). Ten-year overall survival was approximately 80 per cent in both arms, with a p value of 0.7948, and no new safety signals.

Six extra years before the next treatment is a large thing in a disease people live with for decades, and it is the right thing to put in front of someone deciding. So is the fact that it did not change how long they lived, and that two further years of an antibody carries infection risk and clinic visits. Both numbers belong in the conversation.

## Fields

- Kind: Trial
- Status: mixed
- Last checked: 2026-10-01
- Also known as: Primary Rituximab and Maintenance; PRIMA trial; Rituximab maintenance in follicular lymphoma
- Tags: lymphoma-evidence
- Registry id: NCT00140582
- Phase: 3
- Setting: High tumour burden follicular lymphoma responding to first-line immunochemotherapy: two years of rituximab maintenance against observation
- Sponsor: Lymphoma Study Association
- Enrolled: 1018
- Result: Median progression-free survival 10.5 against 4.1 years (hazard ratio 0.61) with no difference in ten-year overall survival, which was about 80 per cent in both arms.
- Outcomes: Progression-free survival (median): Rituximab maintenance 10.5 years vs Observation 4.1 years, HR 0.61; Overall survival at 10 years: Rituximab maintenance 80% vs Observation 80%
- Replication: Consistent with the earlier ECOG and EORTC maintenance trials in relapsed disease; the absence of a survival benefit has been reproduced in every one of them.

## Sources

- ClinicalTrials.gov NCT00140582: https://clinicaltrials.gov/study/NCT00140582
- Lancet 2011: https://doi.org/10.1016/S0140-6736(10)62175-7
- Journal of Clinical Oncology 2019: https://doi.org/10.1200/JCO.19.01073

## Connected records

- cancers: [Follicular lymphoma](https://onco.cc/cancers/follicular-lymphoma/), [Non-Hodgkin lymphoma (all types)](https://onco.cc/cancers/non-hodgkin-lymphoma/)
- fronts: [Immunotherapy](https://onco.cc/fronts/immunotherapy/)
- technologies: [Monoclonal antibodies](https://onco.cc/technologies/monoclonal-antibody/)
- targets: [CD20](https://onco.cc/targets/cd20/)
- drugs: [Cyclophosphamide](https://onco.cc/drugs/cyclophosphamide/), [Doxorubicin](https://onco.cc/drugs/doxorubicin/), [Prednisone](https://onco.cc/drugs/prednisone/), [Rituximab](https://onco.cc/drugs/rituximab/), [Vincristine](https://onco.cc/drugs/vincristine/)
- companies: [LYSA (The Lymphoma Study Association)](https://onco.cc/companies/lysa/)
- terms: [FLIPI, FLIPI2 and POD24 (follicular lymphoma risk)](https://onco.cc/terms/flipi/), [Maintenance and consolidation in lymphoma: where it works and where it does not](https://onco.cc/terms/lymphoma-tx-maintenance/), [Maintenance therapy](https://onco.cc/terms/maintenance-therapy/), [Watchful waiting, and how it differs from active surveillance](https://onco.cc/terms/watchful-waiting/)
- people: [Gilles Salles](https://onco.cc/people/gilles-salles/)
- bottlenecks: [Patients lack understanding, navigation and agency](https://onco.cc/bottlenecks/b-patient-voice/), [Toxicity and quality of life are undervalued](https://onco.cc/bottlenecks/b-toxicity-qol/)
- key papers: [Rituximab maintenance for 2 years in patients with high tumour burden follicular lymphoma responding to rituximab plus chemotherapy (PRIMA): a phase 3, randomised controlled trial](https://onco.cc/key-papers/paper-prima-rituximab-maintenance-follicular-lancet-2011/), [Sustained progression-free survival benefit of rituximab maintenance in patients with follicular lymphoma: long-term results of the PRIMA study](https://onco.cc/key-papers/paper-prima-final-rituximab-maintenance-follicular-jco-2019/)
- roadmaps: [Lymphoma roadmap: from a jaw tumour in Uganda and the first human cancer virus to gene-expression subtypes, PET-adapted chemotherapy, CAR-T cells, bispecific antibodies and the genetics-directed trials now recruiting](https://onco.cc/roadmaps/lymphoma-roadmap/)
- trials: [GALLIUM](https://onco.cc/trials/gallium/), [RELEVANCE](https://onco.cc/trials/relevance/)

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