THOUSANDS OAKS, Calif. (TheStreet) -- Patients with relapsed multiple myeloma benefited more from treatment with Amgen's (AMGN) - Get Amgen Inc. Report Kyprolis than with Velcade, an older, rival drug marketed by Takeda, according to results from a study announced by Amgen on Sunday night.
Amgen believes proving Kyprolis' superiority over Velcade in the second-line multiple myeloma treatment setting further justifies the $10.4 billion paid for Onyx Pharmaceuticals, the developer of the drug. Another large study pitting the two drugs against each other in newly diagnosed multiple myeloma patients is ongoing with results expected next year.
Kyprolis sales in 2014 totaled $331 million. By comparison. Velcade sales were approximately $2.5 billion last year, half those in the U.S. Takeda loses U.S. patent protection on Velcade in 2017, which means Amgen is under a time crunch to prove Kyprolis' superiority before cheap generic versions of Velcade reach the market.
In the "ENDEAVOR" study announced Sunday night, patients with multiple myeloma still progressing despite one to three prior therapies were randomized to receive Kyprolis plus a steroid or Velcade plus the same steroid. Following an interim analysis, patients in the Kyprolis arm had a 47% reduction in the risk of disease worsening or death compared to Velcade. At the median, Kyprolis patients went 18.7 months before their disease progressed compared to 9.4 months for Velcade patients. The benefit favoring Kyprolis was statistically significant.
The study will continue to later assess if there is an overall survival benefit for Kyprolis over Velcade, Amgen said. A full presentation of data from from the ENDEAVOR study will be made at the American Society of Clinical Oncology annual meeting in June.
On safety, Amgen said the rates of heart and kidney failure observed in Kyprolis-treated patients were similar to those seen in a previously conducted phase III study. The number of patients reporting cases of high blood pressure and shortness and breath attributable to Kyprolis were higher in this study than previously reported.
Amgen has already filed a supplemental application with the FDA to expand Kyprolis' approval as a second-line treatment for multiple myeloma. That application was based on positive results from a study combining Kyprolis with Celgene's (CELG) - Get Celgene Corporation Report Revlimid. The FDA is expected to make a decision on or before Nov. 27. Amgen is also seeking European approval for Kyprolis.
The positive results from the ENDEAVOR study came much earlier than investors expected and should help Kyprolis gain on its older rival Velcade. Longer term, however, Amgen faces significant challenges from even newer multiple myeloma therapies under development. Takeda may be a few years from losing patent protection on Velcade but the company will be seeking regulatory approval soon for a new, oral version known as ixazomib. Takeda announced positive results from a phase III study of ixazomib last month.
Also coming are new, novel monoclonal antibody therapies against multiple myeloma. These include daratumumab from a joint venture between Johnson & Johnson (JNJ) - Get Johnson & Johnson Report and Genmab (GNMSF) , Sanofi's (SNY) - Get Sanofi Report SAR650984 and a third product from Celgene in partnership with Morphosys (MPSYY) .
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