Onyx Makes Headway with Carfilzomib - Analyst Blog

Onyx Pharmaceuticals Inc. (ONXX) recently said that the US Food and Drug Administration (FDA) granted a fast track designation to carfilzomib, a next generation proteasome inhibitor, under evaluation for the treatment of patients with relapsed and refractory multiple myeloma.

Earlier, in December last year, Onyx Pharma reported positive results on the candidate from a phase IIb trial (003-A1). The results showed that patients experienced an overall response rate of 24.1%, while the clinical benefit rate was higher at 34.2%. The duration of response was 8.3 months, while the median overall survival was 15.5 months. The patients, who enrolled in the study, had already received a median of five prior lines of therapy and their disease was refractory to their last therapeutic regimen.

On the basis of these results, Onyx Pharma initiated the submission of a rolling New Drug Application (NDA) for gaining accelerated approval of carfilzomib for relapsed and refractory multiple myeloma. The company targets to complete the submission by mid-2011.

Onyx Pharma has an agreement with a Japanese company, Ono Pharmaceutical Co. Ltd., for the development and commercialization of carfilzomib and ONX 0912, in Japan. ONX 0912, the follow-on version of carfilzomib, is currently in phase I testing.

We note that the FDA granted orphan drug designation to carfilzomib for the treatment of multiple myeloma in 2008. Following the drug's approval, this status will allow Onyx Pharma seven years of US marketing exclusivity.

We believe that the approval of carfilzomib would be a major positive for Onyx Pharma, which currently has just one marketed product, Nexavar (cancer), in its portfolio. Nexavar's performance in the recently reported third quarter of 2010 was disappointing with sales declining 1% to $226.2 million. Sales of the drug missed expectations due to unfavorable foreign exchange movement, increased competition, lower sales growth in Japan, pricing pressure in the European Union and the impact of the US health care reform.

Considering the above mentioned factors, we believe management was forced to lower Nexavar sales guidance for the second time in 2010. Onyx Pharma now expects Nexavar sales in the range of $905 – $925 million, down from its earlier guidance of $925 – $975 million.

Nexavar also faces intense competition from Pfizer Inc.'s (PFE) Sutent, Roche Holdings Ltd.'s (RHHBY) Avastin, Novartis AG's (NVS) Afinitor and GlaxoSmithKline plc's (GSK) Votrient. Going forward, we expect investor focus to remain on the approvability of carfilzomib.

 
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