Pharmacyclics' Imbruvica Shows Potential In Multiple Myeloma

Pharmacyclics reported new Phase 2 data for Imbruvica (ibrutunib) as treatment for relapsed or relapsed/refractory multiple myeloma (MM). 

Imbruvica is an oral, once-daily therapy and Bruton's tyrosine kinase (BTK) inhibitor. BTK plays a key part as a signaling molecule in the B-cell receptor and enables malignant B cells to survive and spread. Imbruvica’s mechanism of action helps halt the proliferation and spread of cancer cells. The drug is approved for chronic lymphocytic leukemia (CLL) and mantle cell lymphoma (MCL) and has recently received authorization from Health Canada as treatment for CLL. 

Results from a mid-stage, open label, dose escalation trial which investigated Imbruvica as a single agent or in combination with dexamethasone in 69 previously treated relapsed or relapsed/refractory patients showed anti-tumor activity for both treatment arms. Twenty-five percent of patients who received the combination treatment experienced the highest clinical benefit with one partial response and four minor responses. Another five patients sustained stable disease. The combination treatment of Imbruvica and dexamethasone resulted in positive responses and a median progression-free survival (PFS) of 5.6 months. 

Dr. Thorsten Graef, VP of Clinical Science at Pharmacyclics, said, “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. 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.” 

“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, Associate Professor of Medicine in the Division of Oncology at Washington University School of Medicine in St. Louis, MO. 

Janssen and Pharmacyclics co-developed and commercialized Imbruvica. The partners’ Type II variation application for Imbruvica as treatment for Waldenstrom's Macroglobulinemia (WM) was accepted by the European Medicines Agency (EMA) a few days ago for review.