EMERYVILLE, Calif. ( TheStreet) -- Onyx Pharmaceuticals ( ONXX) is delaying an expected approval filing of its multiple myeloma drug carfilzomib in order to provide regulators with more information about the drug's manufacturing process, the company said Thursday.

Carfilzomib will be filed with the U.S. Food and Drug Administration by the middle of 2011, pushed back from Onyx's earlier estimate of an end-of-2010 filing.

Onyx said the carfillzomib delay came about after FDA raised questions and asked for more information about the company's plans to expand the production of the drug to meet commercial specifications. The clinical profile of carfilzomib has not changed, and no new safety signals have been observed, Onyx said.

"This is a timing issue," said Onyx CEO Tony Coles on a conference call.

Coles added that Onyx still plans to seek carfilzomib's approval under the FDA's accelerated approval regulations, typically reserved for cancer drugs that can show a meaningful benefit for patients who have no other treatment options.

In July, Onyx reported results from a pivotal phase IIb study demonstrating that carfilzomib was able to induce a clinically meaningful tumor response in 24% of multiple myeloma patients with a median duration of response of 7.4 months, according to study results that were independently verified and released by Onyx.

--Written by Adam Feuerstein in Boston.

>To contact the writer of this article, click here: Adam Feuerstein.

>To follow the writer on Twitter, go to http://twitter.com/adamfeuerstein.

>To submit a news tip, send an email to: tips@thestreet.com.
Adam Feuerstein writes regularly for TheStreet.com. In keeping with TSC's editorial policy, he doesn't own or short individual stocks, although he owns stock in TheStreet.com. He also doesn't invest in hedge funds or other private investment partnerships. Feuerstein appreciates your feedback; click here to send him an email.

If you liked this article you might like

Biotech Stock Mailbag: Rebounding From Hillary's Drug Tweet; Global Blood Weighs on Bluebird

The Street Can't Help but Love Amgen

Biotech Stock Bubble Talk Deflated By Cost-Conscious Buyers

Trade-Ideas: Onyx Pharmaceuticals (ONXX) Is Today's "Water-Logged And Getting Wetter" Stock

Jim Cramer's 'Mad Money' Recap: Next Week's Game Plan