The establishment of ibrutinib as a preferred first-line treatment option makes it important to understand the treatment sequence following first-line ibrutinib and the patient characteristics of those treated with a second-line therapy, according to study investigators who used a real-world US administrative claims database to compare time to next treatment (TTNT), healthcare resource utilization (HRU), and healthcare costs between various second-line treatment regimens following first-line ibrutinib therapy. Among participants with chronic lymphocytic leukemia (CLL)/small lymphocytic lymphoma (SLL), frequently used treatment regimens were grouped into the following cohorts: 1) chemoimmunotherapy (CIT) or chemotherapy (CT) only and 2) venetoclax (VEN)- or idelalisib (IDELA)-based regimens. Comparisons of TTNT, HRU, and per-patient and per-month healthcare costs were analyzed during second-line treatment. Among 132 patients with CLL/SLL treated with first-line ibrutinib followed by second-line therapy, regimens included CIT/CT only (48%) and VEN/IDELA (52%). Patients treated with VEN/IDELA-based regimens had significantly longer TTNT compared with those receiving CIT/CT (HR at 12 months = 0.37; P=0.0337). Total mean monthly healthcare costs, including CLL/SLL and non-CLL/SLL-related medical/pharmacy costs, were $1,754 higher, but not significantly different, for patients treated with VEN/IDELA-based regimens compared with CIT/CT. Total mean monthly medical (non-pharmacy) costs were significantly lower for patients receiving VEN/IDELA-based regimens compared with CIT/CT (-$5,202; P=0.036). VEN/IDELA-based regimens may be a better treatment option than CIT/CT following first-line ibrutinib for patients with CLL/SLL, the researchers noted.