Ono Pharmaceutical is paying Onyx Pharmaceuticals about $59 million for exclusive Japanese development and commercialization rights to two of the latter’s proteasome inhibitor oncology candidates, carfilzomib and ONX 0912. Under terms of the deal Onyx could receive up to another $280 million in development and sales-based milestones, plus additional double-digit royalties on net sales in Japan.
The firm is currently preparing an NDA for carfilzomib as a treatment for multiple myeloma and says it expects to file for approval of the drug in the U.S. by the end of 2010 for potential accelerated approval. ONX 0921 is an oral proteasome inhibitor currently in Phase I development.
“Ono is actively engaged in the development and the commercialization of innovative drugs in cancer and related areas,” remarks Gyo Sagara, president and CEO. “This agreement facilitates Ono’s strategic expansion of its development pipeline in the oncology area.”
Carfilzomib is the lead compound in Onyx’s proteasome inhibitor program. In July the firm reported topline results from the Phase IIb study 003-A1, evaluating single-agent carfilzomib in heavily pretreated patients with relapsed and refractory multiple myeloma. The data showed carfilzomib therapy led to an overall response rate (partial response or greater) of 24%, and a median duration of response of over seven months in patients who entered the study after receiving a median of five prior lines of therapy and whose disease was refractory to their last therapeutic regimen.
Also in July Onyx initiated a large randomized international Phase III trial, Aspire, evaluating carfilzomib combined with lenalidomide and low-dose dexamethasone in patients with relapsed multiple myeloma. The firm has an agreement with FDA on a Special Protocol Assessment and has received scientific advice from the European Medicines Agency on the design and planned analysis for the study. An additional Phase III trial is being designed as the basis for European registration. Carfilzomib is separately being evaluated in advanced solid tumors.
Onyx says ONX 0912 is distinct from carfilzomib, although the compound is based on the same chemistry to selectively target the proteasome. On completion of the ongoing Phase I study in advanced refractory or recurrent solid tumors, Onyx says it expects to evaluate ONX 0912 in hematologic malignancies. The firm’s proteasome development program also includes ONX 0914, an immunoproteasome inhibitor it claims has demonstrated activity in preclinical models of autoimmune disorders.