Carfilzomib: Final Phase IIb data

Final data from the open-label, North American pivotal Phase IIb PX-171-003-A1 trial in 257 evaluable patients showed that IV carfilzomib led to a median OS of 15.5 months and produced an ORR of 24.1%, with a median duration of response of 8.3 months and a CBR of 34.2%. OS for responding patients has not yet been reached, but Onyx said it is expected to exceed 19 months. In a subset of patients refractory to Velcade bortezomib in their last line of therapy (n=128), carfilzomib produced an ORR of 19% and a CBR of 31%. In a subset of patients who had received only 1 prior Velcade regimen (n=122), carfilzomib produced an ORR of 30% and a CBR of 40%. Patients received twice-weekly 20 mg/m 2 IV carfilzomib for 3 weeks of the first 28-day cycle, followed by twice-weekly 27 mg/m 2 for 3 weeks in each subsequent 28-day cycle for up to 12 cycles. Data were presented at the American Society of Hematology meeting in Orlando.

In July, Onyx reported top-line data from the trial showing that carfilzomib produced an ORR of 24%, with a median duration of response of 7.4 months and a CBR of 36% (see BioCentury, Aug. 2). The company plans to submit an NDA to FDA as early as mid-2011 seeking accelerated approval for carfilzomib to treat relapsed and refractory MM. In October, Onyx said the submission would be delayed from year end to as early as mid-2011 after FDA requested additional CMC information related to commercial-scale manufacturing during a pre-NDA meeting (see BioCentury, Oct. 11). Ono has exclusive, Japanese rights to develop and commercialize carfilzomib for cancer from Onyx, which gained the compound through its acquisition of Proteolix Inc. in 2009 (see BioCentury, Nov. 23, 2009 & Sept. 13, 2010). ...