NEW YORK (

TheStreet

) -

Onyx Pharmaceuticals

(ONXX)

may look to sell itself, according to

Bloomberg

reports citing unnamed sources familiar with the situation.

Onyx the maker of Nexavar, a kidney-cancer treating drug and cancer treatments in development like carfilzomib and sorafenib, saw its shares jump over 20% to near $46 a share and its 2011 highs on rumors of a potential sale. Shares closed up nearly 14% to $42.80.

According to Bloomberg reports, the company is using

Centerview Partners

to explore strategic options such as a sale of carfilzomib or the entire company.

Carfilzomib, a potential treatment for myeloma is being reviewed by the

U.S. Food and Drug Administration

, meanwhile regorafenib, a colon cancer treatment that Onyx partnered in developing with

Bayer

ended late-stage trials in October after it was shown to improve the survival rates of colon cancer patients.

Onyx was founded in 1992 by Frank McCormick after a merger of pharmaceutical companies Cetus Corp. and Chiron Corp, and in 1996 it filed for an IPO. In 2005, its Nexavar drug was approved for patient treatment, bringing the first new kidney cancer treatment to market in over a decade.

After reporting net profits during the recession, Onyx reported a $84.9 million loss in 2010 on increasing expenses. The South San Francisco -based company has seen its losses and expenses accelerate in 2011.

The company's shares, which reached highs close to $60 a share in late 2007 fell as low as $27.17 a share in 2011 and were up over 6% in 2011 prior to today's rumored sale talks.

-- Written by Antoine Gara in New York