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.