Long-term follow-up of rituximab plus first-line mitoxantrone, chlorambucil, prednisolone and interferon-alpha as maintenance therapy in follicular lymphoma

Purpose: The randomised, controlled OSHO#39 study showed promising results using first-line mitoxantrone, chlorambucil and prednisolone (MCP) chemotherapy plus rituximab in patients with advanced symptomatic follicular lymphoma (FL) in need of therapy. The aim of this long-term follow-up was to investigate whether clinical benefits are maintained after up to 9 years of observation.

Methods: Following the 4-year follow-up of OSHO#39, 77 FL patients who received rituximab plus MCP (R-MCP) and 52 patients who received MCP (129 patients alive and not previously censored in total) were followed for 5 additional years in this prospective, non-interventional, observational study. For the efficacy analysis, data were jointly analysed with OSHO#39 data (FL intention-to-treat population: 105 patients R-MCP, 96 MCP). Patients not included in the 5-year follow-up were censored.

Results: For surviving patients, median follow-up was 102 months (R-MCP) and 87 months (MCP). Although median overall survival (OS) was not yet reached, OS was longer for patients with R-MCP compared with MCP (p = 0.0057), with 8-year-survival rates of 76.1 versus 55.9%. Further time-to-event data were substantially longer for the R-MCP group than for MCP alone: median progression-free survival (PFS) was 93.4 versus 34.9 months, and median event-free survival (EFS) 89.6 versus 26.5 months. Unplanned subanalyses of patients with and without interferon maintenance showed improved PFS and EFS without an impact on OS.

Conclusions: The addition of rituximab to first-line MCP chemotherapy improves clinical outcomes in advanced FL patients and translates into long-term OS benefits. R-MCP remains a promising standard option for this patient group.