Some minor bad news came out this afternoon from Onyx Pharmaceuticals, and its lead drug candidate for patients with multiple myeloma.
The Emeryville, CA-based drug developer said today it is delaying the new drug application for carfilzomib after FDA officials asked for more data to show it can manufacture larger commercial batches that are consistent with the molecules it produced and tested in clinical trials. Onyx (NASDAQ: ONXX) had previously forecasted it would turn in the application by the end of 2010, and now says it will come “as early as mid-year 2011.”
“This is a timing issue,” Onyx CEO Tony Coles said today on a conference call with analysts. “We believe the fundamental value proposition for carfilzomib is unchanged and the commercial opportunity is significant.”
The FDA’s request for more data came after the company made some modifications to its manufacturing process as it attempts to start scaling up for commercial demand. The company saw some “minor variations” that are thought to be related to minor changes in equipment temperatures at the larger scale. Onyx has generated some data already, and is working to produce more, to show its larger-scale process is reproducible and creates a product with the same properties that were observed in the clinical trials.
The new drug is vitally important to Onyx’s growth prospects, as it seeks to diversify beyond its lone marketed product at the moment, sorafenib (Nexavar) for kidney and liver cancer. Onyx agreed to pay $276 million upfront, plus another potential $535 million in milestone payments to obtain carfilzomib last year through the acquisition of South San Francisco-based Proteolix. A few months later, in July, Onyx reported that the new drug helped shrink tumors in about one-fourth of patients who had relapsed after getting prior rounds of treatment. The results were compelling enough to seek FDA approval, even though the drug hasn’t yet completed the third and final stage of clinical trials usually required before a drug can be sold in the U.S.
If the drug is approved, it would be a new treatment option for a disease that hits about 20,000 people each year in the U.S., and kills about half that many every year, according to the American Cancer Society.
Onyx shares fell about 7 percent in after-hours trading following news of the delay.