Early-Phase Study of Acalabrutinib Plus Obinutuzumab in CLL
Posted: Wednesday, March 11, 2020
Overall response rates well above 90% were achieved in both patients with treatment-naive and relapsed or refractory chronic lymphocytic leukemia (CLL) when they were treated with a combination of acalabrutinib and obinutuzumab in a phase Ib/II study. What’s more, at 36 months, 94% and 88%, respectively, remained progression-free, reported Jennifer A. Woyach, MD, of The Ohio State University Comprehensive Cancer Center, Columbus, and colleagues in Cancer Discovery.
The study population included 19 patients with treatment-naive and 26 patients with relapsed or refractory CLL. They received 100 mg of acalabrutinib twice daily until disease progression, along with obinutuzumab (cycle 1: 100 mg on day 1, 900 mg on day 2, 1,000 mg on days 8 and 15; cycles 2–6: 1,000 mg on day 1). The overall response rates were 95% and 92% in the treatment-naive and relapsed or refractory groups, respectively. Grade 3 or 4 adverse events occurred in 71% of patients who received the combination therapy. Furthermore, “32% of treatment-naive and 8% of relapsed/refractory patients achieved complete remission,” noted Dr. Woyach and her team, adding that responses were durable and deepened over time.
The combination of acalabrutinib—a selective BTK inhibitor—and obinutuzumab—a humanized anti-CD20 monoclonal antibody—warrant evaluation in larger, comparative trials, the researchers stated. In fact, additional data are anticipated from an ongoing phase III trial (ClinicalTrials.gov identifier NCT02475681), which is comparing chlorambucil plus obinutuzumab, acalabrutinib alone, and acalabrutinib plus obinutuzumab in previously untreated patients with CLL.
Disclosure: For full disclosures of the study authors, visit cancerdiscovery.aacrjournals.org.