Health care resource utilization in 3L + patients with chronic phase chronic myeloid leukemia receiving asciminib or bosutinib

Objectives: To assess and compare health care resource utilization (HCRU) rates of asciminib and bosutinib at the Week 24, Week 48, and Week 96 cutoffs among 3 L + patients with chronic myeloid leukemia in chronic phase (CML-CP) in the randomized ASCEMBL trial. Methods: Patients in the ASCEMBL trial (Clinicaltrials.gov: NCT03106779) were randomized to receive asciminib 40 mg twice daily (n = 157) or bosutinib 500 mg once daily (n = 76). At each scheduled visit, investigators conducted HCRU assessment on hospitalization, emergency room visit, general practitioner visit, specialist visit and urgent care visit; duration and type of hospitalization for the hospitalized patients; and reasons for HCRU. The number of patients with HCRU, rate of HCRU per patient-year, and length of hospital stay by ward type were compared at Week 24, Week 48, and Week 96 analyses. Results: Lower proportions of patients receiving asciminib versus bosutinib used any resources including hospitalizations, emergency room visits, general practitioner visits, specialist visits, and urgent care visits (23.6% versus 36.8%, 26.1% versus 39.5%, and 28.6% versus 42.6% at Week 24, Week 48, and Week 96 analyses, respectively). After normalizing for treatment exposure, rates of HCRU for any resource per patient-year were significantly lower for asciminib versus bosutinib: 0.25 (95% CI: 0.18–0.34) versus 0.80 (95% CI: 0.55–1.16) at the Week 24 analysis, 0.20 (95% CI: 0.15–0.27) versus 0.47 (95% CI: 0.32–0.66) at the Week 48 analysis, and 0.17 (95% CI: 0.12–0.22) versus 0.40 (95% CI: 0.27–0.55) at the Week 96 analysis. Among the hospitalized patients, mean length of hospital stay was lower for asciminib than bosutinib for most wards at all three timepoints. Conclusions: In the ASCEMBL trial, asciminib-treated patients with CML-CP in 3 L + maintained lower resource utilization compared to bosutinib over the long-term.