ATLANTA, Dec. 8, 2012 /PRNewswire/ -- Pharmacyclics, Inc. (NASDAQ: PCYC) today announced follow-up results that its investigational oral therapy ibrutinib (PCI-32765), as a single agent, resulted in durable responses for patients over 65 years of age with treatment-naive chronic lymphocytic leukemia (CLL) or small lymphocytic lymphoma (SLL) and for those with relapsed/refractory (RR) or high-risk (HR) disease.
In a study of 116 patients, the overall response rate (ORR) was 68 percent in elderly treatment-naive (TN) patients with an estimated 96 percent progression-free survival (PFS) rate at 26 months. In patients with RR CLL/SLL, including those with HR disease, the ORR was 71 percent with an estimated PFS at 26 months of 75 percent.
A second study in 40 patients with HR CLL treated with the combination of ibrutinib and rituximab therapy reported an ORR of 83 percent, with 38 of the 40 patients continuing on therapy without disease progression. Patients with HR disease have inferior responses to standard chemo-immunotherapy and shorter rates of PFS and OS.
These findings, from ongoing Phase 1b/2 and Phase 2 trials, were presented in a press briefing today at the 54 th annual meeting of the American Society of Hematology in Atlanta, GA. CLL and SLL are common B-cell non-Hodgkin lymphomas.In describing the findings of the Phase 1b/2 ibrutinib monotherapy trial, lead investigator John C. Byrd, M.D., said, "We are very encouraged that these results with ibrutinib continue to support the possibility that we can address some of the critical unmet needs in CLL/SLL." Dr. Byrd is the D. Warren Brown Chair of Leukemia Research and Director, Division of Hematology at Ohio State University Comprehensive Cancer Center — Arthur G. James Cancer Hospital and Richard J. Solove Research Institute (OSUCCC — James). In his presentation, Dr. Byrd noted that current therapies have a number of limitations in terms of how long they can be used in a patient and their tolerability, especially in elderly patients. "Further, virtually all patients relapse, and there are few salvage regimens that produce durable remissions," he pointed out.