Some Good News for Onyx Pharma - Analyst Blog

Onyx Pharmaceuticals Inc. (ONXX) recently reported positive results from a mid-stage trial of carfilzomib, a next generation proteasome inhibitor, being studied for the treatment of patients with relapsed and refractory multiple myeloma. Onyx Pharma's shares responded positively to the news with the stock gaining 13.5%.

Patients enrolled in the phase IIb trial (003-A1) experienced an overall response rate of 24.1%, while the clinical benefit rate was 34.2%. The duration of response among the patient population was 8.3 months, while the median overall survival was 15.5 months. The patients, who entered the study, had already received a median of five prior lines of therapy and their disease was refractory to their last therapeutic regimen.

Commonly noted adverse events observed during the study include thrombocytopenia, anemia, lymphopenia, and neutropenia.

Onyx Pharma plans to file a New Drug Application (NDA) with the US Food and Drug Administration (FDA) by mid-2011 for the accelerated approval of carfilzomib for relapsed and refractory multiple myeloma.

The company was initially looking to file for carfilzomib's approval in the US by the end of 2010, which could have resulted in the candidate's approval by mid-2011. However, Onyx Pharma received a setback in October when the Chemistry, Manufacturing and Controls (CMC) review division of the FDA asked for additional CMC information on the manufacturing of carfilzomib. The company had come across certain minor variations in a manufacturing-scale checking.

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-up version of carfilzomib, is currently in phase I testing.

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 were lower than 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.

We believe all these factors forced management to lower 2010 Nexavar sales guidance for the second time this year. 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 company's regulatory plans for carfilzomib.

 
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