SAN DIEGO & RARITAN, N.J.—On Dec. 3, Janssen Research & Development LLC announced the longest follow-up results to date of patients treated with Imbruvica (ibrutinib) for chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL), showing high and lasting responses through five years.
These updated Phase 1b/2 data demonstrated an overall response rate (ORR) of 89 percent, including patients with genetic mutations associated with poor outcomes. A complete response (CR) was observed in 29 percent of patients treated in the first-line setting. Progression-free survival (PFS) was improved with earlier initiation of therapy across treatment-naïve (TN) and relapsed/refractory (r/r) patients.
Additional follow-up data in patients with CLL/SLL treated with Imbruvica through 29 months from the Phase 3 RESONATE-2 trial were also presented. Imbruvica, a first-in-class Bruton’s tyrosine kinase (BTK) inhibitor, is jointly developed and commercialized by Janssen Biotech Inc. and Pharmacyclics LLC, an AbbVie company.
“These longer-term results demonstrate that ibrutinib can help patients keep chronic lymphocytic leukemia and small lymphocytic lymphoma in a remission for an extended period of time, through five years, without chemotherapy,” said Dr. Susan O’Brien, associate director for clinical science at the Chao Family Comprehensive Cancer Center at UC Irvine Health, medical director of the Sue and Ralph Stern Center for Clinical Trials & Research and an investigator and presenter of the PCYC-1102 and PCYC-1103 trials. “In addition, these data indicate the time without disease progression is longer for patients when treatment with ibrutinib is started as early as possible in the course of the disease.”
In the abstract presentation for “Five-Year Experience With Single-Agent Ibrutinib In Patients With Previously Untreated And Relapsed/Refractory Chronic Lymphocytic Leukemia/Small Lymphocytic Leukemia,” Janssen showed that in the PCYC-1102 and PCYC-1103 studies, with five years of follow-up, the ORR in patients treated with Imbruvica was 89 percent, with 14 percent of patients achieving CR and 89 percent ORR with 10 percent CR in r/r patients. Median time on study was 62 months for TN patients and 49 months for r/r patients. Overall survival (OS) at five years was 92 percent for TN patients and 57 percent for r/r patients, with a PFS rate of 92 percent and 43 percent, respectively. Median OS and median duration of response was not reached. Median PFS was not reached in TN patients and was 52 months for r/r patients.
Findings were consistent in r/r patients with high-risk CLL/SLL, and risk factors traditionally associated with poor outcomes, including those with deletion 11q, deletion 13q, deletion 17p and unmutated immunoglobulin heavy-chain variable-region.
“We continue to learn about the full potential that Imbruvica may offer patients with chronic lymphocytic leukemia and small lymphocytic lymphoma. The longer-term data through five years add strong evidence about the extended use of Imbruvica across a wide spectrum of patients,” said Dr. Craig Tendler, vice president of Late-Stage Development and Global Medical Affairs for Oncology, Janssen Research & Development. “We are very encouraged to see such improvements in long-term clinical outcomes for the ibrutinib-treated CLL population, especially for those patients with poor prognostic risk factors.”
With the abstract for “Updated Efficacy and Safety From The Phase 3 RESONATE-2 Study: Ibrutinib as First-Line Treatment Option in Patients 65 Years and Older With Chronic Lymphocytic Leukemia/Small Lymphocytic Leukemia,” Janssen shared updated findings from the pivotal Phase 3 RESONATE-2 trial (PCYC-1115) that demonstrated that at a median of 29 months of follow-up, Imbruvica continued to have substantial efficacy as first-line therapy in CLL/SLL. The study found Imbruvica reduced the risk of progression or death by 88 percent compared with commonly used chemotherapy agent chlorambucil. At 24 months, PFS was 89 percent for patients taking Imbruvica and 34 percent for chlorambucil. Investigator-assessed ORR with this longer follow up was 92 percent with ibrutinib and 36 percent with chlorambucil; in the ibrutinib arm, CR or CR with incomplete bone marrow recovery improved from 15 percent at 24 months to 18 percent with longer follow-up of 29 months.
RESONATE-2 is a continuing Pharmacyclics-sponsored, randomized multicenter, open-label, Phase 3 study, which enrolled 269 TN patients with CLL/SLL aged 65 years or older in the United States, European Union and other regions.