New IMBRUVICA® (ibrutinib) Phase II data announced here today by Pharmacyclics, Inc. (NASDAQ: PCYC) during the 56th American Society of Hematology (ASH) Annual Meeting suggests that IMBRUVICA demonstrates anti-tumor activity both as a single-agent and as combination therapy in heavily pre-treated patients with relapsed or relapsed/refractory multiple myeloma (MM). IMBRUVICA is jointly developed and commercialized by Pharmacyclics and Janssen Biotech, Inc.
"We are very encouraged by the data suggesting anti-tumor activity of IMBRUVICA in multiple myeloma, considering the benefit we have seen in patients with this difficult-to-treat B-cell malignancy," said Thorsten Graef, M.D., Ph.D., Vice President, Clinical Science, Pharmacyclics. "We are committed to investigating and understanding the potential clinical utility of IMBRUVICA in other malignancies and among patients in need of safe and effective treatment options."
Data from an open-label, Phase II dose escalation trial evaluated potential IMBRUVICA dosing regimens either as a monotherapy or in combination with dexamethasone 40mg in the treatment of 69 heavily pre-treated (relapsed or relapsed/refractory) patients. Efficacy and safety were assessed at four-week intervals using the International Myeloma Working Group (IMWG) response criteria for efficacy results and Common Terminology Criteria for AEs (CTCAE) to evaluate safety.
Heavily pre-treated patients (median of 4.5 prior lines of therapy) who received IMBRUVICA 840mg daily in combination with dexamethasone 40mg weekly (n=20) experienced the highest clinical benefit rate of 25%, including one partial response (PR) and four minor responses (MR). Also, an additional five patients (25%) showed sustained stable disease (SD; >4 cycles). IMBRUVICA-treatment in combination with dexamethasone resulted in positive responses and disease stabilization which led to a median progression-free survival (PFS) of 5.6 months. As a result of this trend toward improved efficacy and manageable toxicities, investigators expanded the treatment group per protocol design. Twenty-three additional patients are currently enrolled in this cohort; follow-up is ongoing. Based on these encouraging data, IMBRUVICA is currently being evaluated as a combination agent to treat relapsed/refractory multiple myeloma with agents such as carfilzomib. For more information about these trials, visit www.clinicaltrials.gov.
"IMBRUVICA has shown its effectiveness in other difficult-to-treat blood cancers, so the results of this dose escalation trial in multiple myeloma patients with relapsed/refractory disease is promising," said Ravi Vij, M.D., MBBS,* Associate Professor of Medicine in the Division of Oncology at Washington University School of Medicine in St. Louis, MO, who presented these results in an oral presentation.
The safety profile of IMBRUVICA was tolerable, with similar AE rates across dosing cohorts. Across all cohorts, 57% of patients experienced Grade 3 or greater adverse events (AEs). The most commonly reported non-hematologic AEs of any grade were: diarrhea (51%); fatigue (41%); nausea (35%); dizziness (25%); and, muscle spasms (23%). Myelosuppression had an overall incidence of any grade anemia (29%), thrombocytopenia (23%), and neutropenia (7%), with 16%, 9% and 4% being Grade 3, respectively. Notably, there were no clinically meaningful differences among dose levels. Thirty-three percent of patients experienced a treatment-emergent serious AE. At the time of data cut-off, four patients remained on treatment; the most common reason for treatment discontinuation in 47% was progressive disease.