The latest data from a phase 2 trial examining patients with chronic lymphocytic leukemia treated with combination ibrutinib and venetoclax with a particular focus on minimal residual disease (MRD) assessment was presented by study authors at the 63rd ASH Annual Meeting & Exposition.

Eighty patients were enrolled into the study with a median follow-up of 44.1 months. Patients received 420 mg of ibrutinib daily for 3 cycles followed by an addition of venetoclax with a weekly dose-escalation to 400 mg daily.

According to researchers, during the first 3 cycles of ibrutinib monotherapy, 5 patients discontinued the study and 75 patients initiated venetoclax.

“After 24 cycles of the combination, 53/80 (66%) achieved bone marrow undetectable minimal residual disease (BM U-MRD) remission; 14/80 (17%) were BM MRD+ (low MRD+, n=13; high MRD+, n=1),” stated authors of the study. “Overall, 60/80 (75%) achieved BM U-MRD as the best response.”

According to authors of the study, additional venetoclax appears to lead to U-MRD remission in the majority of a small subset of patients with BM MRD+ disease at 24 cycles of combined therapy.

“Remissions were durable with some patients having recurrence of blood MRD in follow-up, which may be an early indicator of relapse,” stated authors of the study. “Whether this will lead to improved long-term PFS remains to be determined.”

Reference:
Jain N, Keating MJ, Thompson PA, et al. Combined ibrutinib and venetoclax for first-line treatment of patients with chronic lymphocytic leukemia (CLL): focus on long-term MRD results. Poster presented at: 63rd ASH Annual Meeting & Exposition; December 11-14, 2021; Atlanta, GA.