Keryx Biopharmaceuticals, Inc. (Nasdaq: KERX) (the "Company") today announced that a manuscript entitled "Perifosine Plus Bortezomib and Dexamethasone in Relapsed/Refractory Multiple Myeloma Patients Previously Treated with Bortezomib: Results of a Multicenter Phase l/2 Trial" reporting Phase 1 / 2 combination activity of KRX-0401 (perifosine) in the treatment of advanced multiple myeloma (MM) patients, was selected for publication in the October 11, 2011 online edition of the Journal of Clinical Oncology (JCO). Perifosine, the Company's novel, potentially first-in-class, oral anti-cancer drug candidate that inhibits Akt activation in the phosphoinositide 3-kinase (PI3K) pathway is currently being investigated in a Phase 3 trial comparing perifosine + bortezomib + dexamethasone versus placebo + bortezomib + dexamethasone in relapsed/refractory MM patients previously treated with bortezomib. The ongoing Phase 3 study is being conducted under a Special Protocol Assessment (SPA), and with Orphan Drug Status and Fast Track designation in MM. Perifosine is also currently in Phase 3 clinical development for refractory advanced colorectal cancer, also under an SPA and Fast Track designation.
In this Phase 1 / 2 study, perifosine in combination with bortezomib +/- dexamethasone was evaluated in 84 heavily pre-treated patients with relapsed or relapsed/refractory MM. All patients were required to receive prior bortezomib and most were bortezomib refractory (73%). The combination demonstrated an overall response rate (ORR) including MR or > of 41% in all evaluable patients, with stable disease observed in an additional 41% of evaluable patients. The ORR was 65% for bortezomib-relapsed patients and 32% for patients with bortezomib-refractory disease. Median progression-free survival (PFS) was 6.4 months, with a median PFS of 8.8 months in the bortezomib-relapsed population. Median overall survival (OS) was 25 months. Therapy was generally well-tolerated; toxicities, including gastrointestinal side-effects and fatigue, proved manageable. No treatment-related mortality was seen.
The investigators concluded that the combination of perifosine and bortezomib is active and well-tolerated in heavily pre-treated MM patients previously treated with bortezomib, and that the survival data in this study is encouraging, even in patients previously exposed to, and refractory to, bortezomib, as well as prior immunomodulatory drugs.