SOUTH SAN FRANCISCO, Calif. ( TheStreet) -- U.S. regulators have approved Onyx Pharmaceuticals' ( ONXX) multiple myeloma drug Kyprolis. Onyx shares rose 12% to $76.47 in late Friday trading. Kyprolis will be used to treat patients with multiple myeloma that is no longer responding to other therapies, including Celgene's ( CELG) Revlimid or Thalomid and Takeda's Velcade. Onyx will be ready to launch the drug on Aug. 1. One 28-day treatment cycle of Kyprolis therapy will cost $9,950, higher than what the Street was expecting. Patients in the Kyprolis clinical trial were on drug about 4.4 months, Onyx said. "The approval of Kyprolis provides a treatment option to patients with multiple myeloma whose disease has progressed despite use of available therapies," said FDA's cancer drug chief Richard Pazdur, in a statement. "We are encouraged by the continued progress in the development of drugs for multiple myeloma over the past decade, offering improved treatment of this disease." "Today's approval is a significant milestone for Onyx and, most importantly, for patients with advanced myeloma who have few treatment options available to them," said Onyx CEO Tony Coles, in a statement. Ligand Pharmaceuticals ( LGND) will receive a royalty on Kyprolis sales. Ligand shares were down 11 cents to $17.42 in recent trading. --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: email@example.com. Follow TheStreet on Twitter and become a fan on Facebook.