Reasons for initiation of treatment and predictors of response for patients with Rai stage 0/1 chronic lymphocytic leukemia (CLL) receiving first-line therapy: an analysis of the Connect CLL cohort study.

A 'watch-and-wait' strategy is recommended for most patients with early-stage chronic lymphocytic leukemia (CLL) prior to treatment initiation. In the Connect CLL registry, a prospective observational cohort study of 1494 patients treated in 199 US centers, median time to first-line treatment initiation was 3.8, 1.5, and 0.6 years for patients with Rai stage 0, 1, and ≥2, respectively. Only 60% of patients with Rai stage 0/1 underwent FISH/cytogenetic testing prior to initiation of a new line of therapy. Lymphocytosis and lymphadenopathy were the most common reasons for treatment initiation. Lymphocytosis as a reason for treatment initiation was associated with inferior event-free survival at Rai stage 0/1. Short treatment duration was associated with inferior overall survival regardless of Rai stage; sensitivity analyses confirmed the association. The Connect CLL registry provides valuable information on a real-world population of patients with CLL, clarifying both the timing and rationale for initiating therapy.