SWOG S0016 15‑year follow-up: First-line CHOP-based therapy in advanced-stage FL

15-year follow-up results from the phase III, multicenter, randomized, SWOG S0016 trial (NCT00006721), evaluating rituximab + cyclophosphamide + doxorubicin + vincristine + prednisone (R‑CHOP; n = 267) vs CHOP followed by radioimmunotherapy (CHOP‑RIT; n = 264) for the treatment of adults with previously untreated, CD20‑positive, advanced-stage or bulky stage II follicular lymphoma (FL), were published in JAMA Oncology by Shadman et al.The primary endpoints were progression-free survival (PFS) and overall survival (OS).

Key data:The 15-year OS rate for the overall cohort was 70% (95% confidence interval [CI], 65.9–74.1), with no difference between the R‑CHOP and CHOP‑RIT treatment arms (73% vs 67%, respectively; p = 0.56). The 15‑year PFS rate for the overall cohort was 40% (95% CI, 36.0–44.7), with CHOP‑RIT demonstrating a higher PFS rate vs R‑CHOP (47% vs 34%; p = 0.004). Cure modeling estimated an overall cure rate of 42% (95% CI, 33–52), with rates highest among patients with Follicular Lymphoma International Prognostic Index (FLIPI) score 0–1 and normal β2 microglobulin (β2M) levels. Relapse rates declined from 6.8% during Years 0–5 to 0.6% during Years 15–20.  Secondary cancers occurred in 22.1% and 19.7% of patients receiving R‑CHOP and CHOP‑RIT, respectively. 

Key learning: These 15‑year follow-up results show first-line treatment with R‑CHOP or CHOP‑RIT demonstrated favorable long-term survival outcomes in patients with advanced-stage FL and suggest that cure may be possible for a substantial subset of patients.