The Phase 2 trial, evaluating ibrutinib in combination with rituximab, was led by Jan A. Burger, M.D., Ph.D., associate professor, Department of Leukemia, Division of Cancer Medicine, The University of Texas MD Anderson Cancer Center, Houston, TX.
"We are very excited by the response rates we saw with ibrutinib-rituximab combination therapy, and believe they emphasize the need for rapid, further development of ibrutinib, especially for patients with high-risk CLL/SLL," said Dr. Burger.
Studies and Findings Oral presentation 189, The Bruton's Tyrosine Kinase (BTK) inhibitor ibrutinib (PCI-32765) promotes high response rate, durable remissions, and is tolerable in treatment naive (TN) and relapsed or refractory (RR) chronic lymphocytic leukemia (CLL) or small lymphocytic lymphoma (SLL) patients including patients with high-risk (HR) disease: New and updated results of 116 patients in a phase Ib/II study John C. Byrd, M.D., The Ohio State University, Columbus, OH
This presentation was based on findings from a Phase 1b/2, multi-center trial with 116 patients with TN (n=31), RR (n=61) or HR (n=24) CLL/SLL. Patients were treated with oral ibrutinib monotherapy, either 420 mg or 840 mg daily. Patients with RR disease had received at least two prior therapies; patients with HR disease had relapsed within two years following chemo-immunotherapy. The study objectives were to determine the ORR, PFS, overall safety (OS), safety of the two dosing regimens and pharmacokinetics/pharmacodynamics.
- The overall response rates were:
- 68 percent in TN patients, all of whom were over 65 years old, after a median follow up of 20.3 months
- 71 percent in patients with RR disease, including patients with HR CLL/SLL, after a median follow up of 15.7 months
- The estimated PFS at 26 months is 96 percent for patients over 65 years of age with TN CLL and 75 percent for those with RR/HR disease
- Estimated OS at 26 months is 96 percent in TN patients and 83 percent in patients with RR/HR disease