Amgen Inc. may finally acquire Onyx Inc. after the Thousand Oaks company raised its bid for the cancer drug developer, according to media reports.

Amgen has increased its bid to $130 a share, an 8 percent increase from its previous offer of $120, according to a Bloomberg New report on Tuesday. And Reuters on Wednesday reported the companies were negotiating a final deal that may be announced within a week. Both reports were based on anonymous sources.

A $130 buyout price would put the total acquisition cost at roughly $9.5 billion.

Based in South San Francisco, Onyx makes Nexavar, a treatment for liver and kidney cancer that has global sales topping $1 billion. The proceeds are shared with German pharmaceutical company Bayer AG. It also makes Stivarga, a new colon cancer drug.

Onyx first announced it had received a buyout offer from Amgen on June 30. Its board rejected the $120 offer, saying the price significantly undervalued the company, even though it was a 38 percent premium to the previous closing price. Shares of Onyx quickly spiked above $120.

Shares of Amgen gained $7.18 cents, or 6.8 percent, to close at $112.40 on Wednesday. Shares of Onyx lost $3.81, or 2.8 percent, to $128.21. Both issues trade on the Nasdaq.