- Acalabrutinib+obinutuzumab demonstrated high-level response with minimal grade 3-4 adverse events (AEs) at 3-year follow-up in patients with treatment-naive or relapsed/refractory chronic lymphocytic leukemia (CLL).
Why this matters
- Acalabrutinib monotherapy has previously demonstrated >93% objective response rate (ORR) in CLL.
- 3-year follow-up of a phase 1b/2 study to investigate acalabrutinib+obinutuzumab in treatment-naive (n=19) and relapsed/refractory (n=26) CLL.
- Median patient age, 61 (range, 42-76) years.
- 53% of treatment-naive patients and 50% of those with relapsed/refractory disease had bulky disease.
- Funding: Acerta Pharma.
- Treatment-naive group: 95% ORR; 31.6% complete response (CR); 63.2% partial response (PR).
- Relapsed/refractory group: 92% ORR; 7.7% CR; 84.6% PR.
- Treatment-naive group at 39 months: 94.4% (95% CI, 66.6-99.2).
- Relapsed/refractory group at 42 months: 72.7% (95% CI, 43.8-88.4).
- Minimal residual disease (MRD) in bone marrow:
- Treatment-naive group: 26%.
- Relapsed/refractory group: 15%.
- MRD negativity in peripheral blood was durable.
- Incidence of grade 3-4 adverse events was minimal, with a 2% discontinuation rate.
- Bone marrow biopsies were only performed to confirm CR in patients with MRD negativity in peripheral blood; some CRs may have therefore have been classed as PRs.
- Matthew S. Davids, MD, associate director of the CLL Center at Dana-Farber Cancer Institute and assistant professor of medicine at Harvard Medical School, Boston, Massachusetts, noted that the acalabrutinib regimen described requires continuous therapy to maintain response and mentioned a study in which he is involved that aims to find whether the addition of venetoclax to the regimen may enable a fixed-duration regimen.