How to determine post-FCR therapy for cytogenetic risk-tailored elderly patients with chronic lymphocytic leukemia, maintenance rituximab or observation

The open-label, prospective, observational study aimed to evaluate whether the addition of maintenance rituximab (MR) improved progression-free survival (PFS) and overall survival (OS), after fludarabine, cyclophosphamide, and rituximab (FCR) for cytogenetic risk-tailored elderly patients with chronic lymphocytic leukemia (CLL). Enrolled 201 patients (ages 65–84 years) who received FCR and gained an overall response. One hundred and four of 201 patients were in the observation (OBS) arm while 97/201 patients continued to receive MR therapy. After FCR, no more benefits were provided by MR versus OBS in cytogenetic better intermediate-risk cohort. PFS at 10 years reached 68.6 versus 58.1 % (P > 0.05). Ten-year OS was 81.8 versus 74.6 % (P > 0.05). However, the improvement of PFS and OS were as dramatic as the improvements of being MR treating versus OBS mainly in the poor-risk cohort. PFS at 10 years reached 57.1 versus 22.7 % (P < 0.01), and 10-year OS was 71.2 versus 41.7 % (P < 0.01). Compared with OBS, no severe hematologic adverse events (AEs) (Grades 3–4) appeared in patients with MR; only some mild non-hematologic AEs incurred (nausea–vomiting 0.96 %, allergy 1.9 % and infection 1.9 %) during the maintenance treatment. The study showed that MR improved 10-year RFS and OS for cytogenetic poor-risk patients with CLL.