Fixed-Duration Acalabrutinib Combinations in Untreated Chronic Lymphocytic Leukemia

BACKGROUND: Whether fixed-duration acalabrutinib-venetoclax (with or without obinutuzumab) would result in better progression-free survival than chemoimmunotherapy in patients with untreated chronic lymphocytic leukemia (CLL) is unknown. METHODS: mutation. Patients were randomly assigned, in a 1:1:1 ratio, to receive acalabrutinib-venetoclax (acalabrutinib, cycles 1 to 14; venetoclax, cycles 3 to 14), acalabrutinib-venetoclax-obinutuzumab (as above, plus obinutuzumab, cycles 2 to 7), or chemoimmunotherapy with the investigator's choice of fludarabine-cyclophosphamide-rituximab or bendamustine-rituximab (cycles 1 to 6). The primary end point was progression-free survival (acalabrutinib-venetoclax vs. chemoimmunotherapy) in the intention-to-treat population, assessed by blinded independent central review. RESULTS: . Estimated 36-month progression-free survival at a median follow-up of 40.8 months was 76.5% with acalabrutinib-venetoclax, 83.1% with acalabrutinib-venetoclax-obinutuzumab, and 66.5% with chemoimmunotherapy (hazard ratio for disease progression or death with acalabrutinib-venetoclax vs. chemoimmunotherapy, 0.65 [95% confidence interval {CI}, 0.49 to 0.87], P = 0.004; for the comparison of acalabrutinib-venetoclax-obinutuzumab with chemoimmunotherapy, P<0.001). Estimated 36-month overall survival was 94.1% with acalabrutinib-venetoclax, 87.7% with acalabrutinib-venetoclax-obinutuzumab, and 85.9% with chemoimmunotherapy. Neutropenia, the most common adverse event of clinical interest of grade 3 or higher, was reported in 32.3%, 46.1%, and 43.2% in the three groups, respectively; death from coronavirus disease 2019 was reported in 10, 25, and 21 patients in the three groups. CONCLUSIONS: Acalabrutinib-venetoclax with or without obinutuzumab significantly prolonged progression-free survival as compared with chemoimmunotherapy in fit patients with previously untreated CLL. (Funded by AstraZeneca; AMPLIFY ClinicalTrials.gov number, NCT03836261.).