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.