Extended ibrutinib treatment showed sustained efficacy in patients with previously treated chronic lymphocytic leukaemia or small lymphocytic lymphoma, six-year results from the RESONATE trial shows.

Presenting the findings at Blood 2019 during the HSANZ free communications CLL session, Professor Stephen Mulligan, a co-investigator and haematologist at the Royal North Shore Hospital in Sydney, said the results further established the long-term benefit and tolerability for continuous ibrutinib treatment in this patient group.

Results from the final analysis showed that the median overall survival in patients randomised to the ibrutinib arm (n=195) was 68 months compared to 65 months (n=196) in the ofatumumab arm, without adjusting for crossover.

Similar efficacy was seen in patients with high-risk genomic features.

Ibrutinib-treated patients had significant sustained PFS benefits compared to ofatumumab (median PFS 44.1 vs 8.1 months).

The ORR was 91% with ibrutinib and the proportion of patients with best response of CR/ CRi increased over time to 11% with the current follow-up.

Hypertension occurred in 21% of patients (9%, grade ≥3) and atrial fibrillation in 12% (6%, grade ≥3) and major hemorrhage occurred in 10%.

Professor Mulligan noted that the prevalence of any grade ≥3 adverse event with ibrutinib decreased after the first year of treatment and remained stable thereafter.

The most common reasons for ibrutinib discontinuation prior to study closure were physician decision (37%) and adverse events (16%).