EXHIBIT 99.1


            ONYX ANNOUNCES PRICING OF COMMON STOCK IN PUBLIC OFFERING


RICHMOND, Calif., July 22, 2003 - Onyx Pharmaceuticals, Inc. (Nasdaq:ONXX) today
announced that it has priced an offering of 5 million shares of its common stock
at $15.25 per share for estimated net proceeds to Onyx of approximately $71.2
million. The underwriters have a 30-day option to purchase up to 750,000
additional shares of its common stock from the company solely to cover
over-allotments, if any. All of the shares of common stock are being offered by
Onyx pursuant to an effective registration statement previously filed with the
Securities and Exchange Commission. Morgan Stanley & Co. Incorporated, together
with Lehman Brothers and SG Cowen Securities Corporation, are acting as the
representatives of the underwriters for the offering. Morgan Stanley is acting
as sole bookrunner for the offering.

This press release shall not constitute an offer to sell or the solicitation of
an offer to buy, nor shall there be any sale of these securities in any
jurisdiction in which such offer, solicitation or sale would be unlawful prior
to the registration or qualification under the securities laws of any
jurisdiction. The shares of common stock may only be offered by means of a
prospectus. Copies of the final prospectus supplement and accompanying
prospectus can be obtained from the Prospectus Departments of Morgan Stanley &
Co. Incorporated (1585 Broadway, New York, NY 10036, fax +1-212-761-0211),
Lehman Brothers (c/o ADP Financial Services, Integrated Distribution Services,
1155 Long Island Avenue, Edgewood, NY 11717, fax +1-631-254-7628), or SG Cowen
Securities Corporation (c/o ADP, 1155 Long Island Avenue, Edgewood, NY 11717,
fax +1-631-254-7628) or from Onyx (3031 Research Drive, Richmond, CA 94806, fax
+1-510-222-9758).

ABOUT ONYX PHARMACEUTICALS

Onyx Pharmaceuticals is engaged in the development of novel cancer therapies and
has proprietary technologies that target the molecular basis of cancer. The
company is developing small molecule drugs, including BAY 43-9006 in
codevelopment with Bayer Pharmaceuticals Corporation. For more information about
Onyx's pipeline and activities, visit the company's website at
www.onyx-pharm.com.

This news release contains forward-looking statements regarding expectations as
to the completion of and proceeds from any public offering. A number of risks
and uncertainties could cause actual events to differ from the company's
expectations indicated by these forward-looking statements. These risks include
successful closing with the underwriters and completion of the offering, as well
as other risks addressed in the company's periodic reports filed with the
Securities and Exchange Commission, including but not limited to its Annual
Report on Form 10-K filed on March 25, 2003 and its Quarterly Reports on Form
10-Q.