Long-term 3-year follow-up of mosunetuzumab in relapsed or refractory follicular lymphoma after ≥2 prior therapies.
- Study type
- Clinical trial
- Study name
- GO29781
- Design
- Single-arm study with fixed-duration treatment; long-term follow-up report (median follow-up 37.4 months)
- Sample size
- 90 patients
- Source
- Blood · 2025
- Trial registration
- NCT02500407
In plain words
This report gives the results of about three years of follow-up of 90 patients with follicular lymphoma whose disease had come back after at least two earlier treatments and who received the drug mosunetuzumab, a medicine that links the body's immune cells to lymphoma cells. This treatment is given for a fixed length of time and then stopped. About six in ten patients had a complete response (no detectable lymphoma), and in most of them the remission lasted for years. After three years, about 8 in 10 patients were alive, and no new serious side effects were seen with longer follow-up.
Key results
Treatment arms and regimens
Mosunetuzumab IV in 21-day cycles with step-up dosing in cycle 1: 1 mg on day 1, 2 mg on day 8 and 60 mg on day 15; 60 mg on day 1 of cycle 2; then 30 mg on day 1 of cycle 3 onwards. Patients with a complete response completed treatment after 8 cycles, and those with a partial response or stable disease continued for up to 17 cycles.
Source of the regimen details: Primary phase 2 report (Lancet Oncol 2022) and the FDA label for LUNSUMIO (Dosage and Administration section)
Doses are given for the information of specialists, as in this study’s protocol, and are not a prescription. Every drug must be prescribed by the treating physician for the individual patient.
Study population
Patients with relapsed or refractory follicular lymphoma (FL) who had received two or more prior lines of therapy, including patients with high-risk disease.
Endpoints
Investigator-assessed complete response (CR) rate and objective response rate, duration of response, duration of complete response, progression-free survival, overall survival, time to B-cell recovery and safety.
Safety and side effects
With longer follow-up, no new cytokine release syndrome events and no new fatal, serious or grade 3 or higher adverse events were reported. Median time to recovery of CD19+ B cells after 8 cycles of treatment was 18.4 months (95% CI 12.8–25.0).
Clinical significance and place in guidelines
This 3-year follow-up shows the durability of responses to fixed-duration mosunetuzumab in relapsed or refractory FL after two or more lines of therapy and raises no late safety concerns; this supports its outpatient use as an option in later lines of FL therapy.
Limitations
Single-arm, uncontrolled study with a limited number of patients (90). Responses were investigator-assessed. Given the long natural history of follicular lymphoma, 3 years of follow-up is still short for a full assessment of long-term outcomes.
This summary was prepared by the editorial team from the published paper; the original paper is the final reference. Read the original abstract on PubMed.