Data Supports Progression-Free Survival, Overall Survival for Long-Term CLL/SLL Treatment Landing Page

First-line single-agent ibrutinib treatment is effective for up to seven years in patients with chronic lymphocytic leukemia (CLL), according to phase 3 data presented in an AbbVie press release.

The RESONATE-2 study enrolled 269 patients who were at least 65 years of age. Patients had previously untreated CLL/small lymphocytic leukemia, without 17p deletion, and received continuous single-agent ibrutinib until progression, or chlorambucil up to 12 cycles.

Ibrutinib is a once-daily oral BTK inhibitor. Seven years of follow-up data indicated that progression-free survival (PFS) with ibrutinib was sustained (Hazard Ratio [HR] 0.160 [95% Confidence Interval (CI): 0.111–0.230]). At 6.5 years, PFS with ibrutinib was 61%, compared with 9% in the chlorambucil arm.

Additionally, the ibrutinib arm saw an overall survival rate of 78% and an overall response rate of 92%. The complete response rate increased over time to 34%, and nearly half of patients continued long-term treatment with ibrutinib.

“These data add to the overall body of evidence that patients treated with ibrutinib can achieve extended progression-free survival and overall survival when used as a first-line therapy,” said Paul M Barr, MD, lead study investigator and professor of medicine at the Wilmot Cancer Institute, University of Rochester. “The results add to the extensive clinical evidence supporting the use of single-agent ibrutinib for long-term disease control.”

Adverse events (AEs) accounted for 23% of patients in the ibrutinib arm discontinuing treatment. Findings regarding AEs included the following:

• Ongoing rates of Grade 3 or higher AEs of interest remained low for hypertension (five-to-six-year interval: n=20; six-to-seven-year interval: n=15) and atrial fibrillation (five-to-six-year interval: n=7; six-to-seven-year interval: n=5).

• Across full follow-up, 31 patients had dose reductions due to any-grade AEs.

• Of the patients who had a dose reduction, 71% had resolution or improvement of the AE.

Findings from the RESONATE-2 study are the longest phase 3 survival data for a BTK inhibitor in CLL.

“With long-term safety and efficacy data for IMBRUVICA in CLL, these latest data from the RESONATE-2 study further reinforce IMBRUVICA as a standard of care that can help patients live longer without chemotherapy,” said Danelle James, MD, MAS, Imbruvica global development lead, Pharmacyclics LLC.

Reference:
Results from IMBRUVICA® (ibrutinib) RESONATE-2 study provide up to seven years of progression-free and overall survival data in first-line chronic lymphocytic leukemia (CLL). News release. Pharmacyclics LLC. June 4, 2021. Accessed September 14, 2021. https://www.pharmacyclics.com/press-room/press-article@article=48f4b351-e18e-61a6-ac91-ff01003424c7.html