NEW YORK ( TheStreet) -- After a tortuous courtship, including Onyx Pharmaceuticals ( ONXX) rejection of an initial $120 per share bid from Amgen ( AMGN), and a subsequent auction that may have had most of big pharma looking over the wares, the companies said Sunday they had clinched a deal at $125 per share, or $10.4 billion. The total comes to $9.4 billion net of Onyx cash. "We believe that Amgen is ideally suited to realize the full potential of Onyx's portfolio and pipeline for the benefit of physicians and patients," said Amgen CEO Robert Bradway in a statement. "Our acquisition of Onyx follows a thorough due diligence process and is fully consistent with our strategy of advancing innovative medicines that address serious unmet medical needs. We expect this acquisition will accelerate growth and enhance value for Amgen shareholders." The deal bolsters Amgen's cancer treatment pipeline, with Onyx's drug Kyprolis, a type of proteasome inhibitor that treats relapsed and refractory multiple myeloma, being one of the keys to the deal. Indeed, shortly before the deal was announced, the buyer was asking for a look at incomplete Kyprolis trials, although that was likely more of a negotiating tactic than a dealbreaker. The Food and Drug Administration offers urgently needed drugs accelerated approval based on preliminary data. However, the drug company must continue to pursue more proof of the drug's clinical effectiveness to attain permanent, or regular, approval. To attain that approval, and market the drug in the EU, South San Francisco, Calif.-based Onyx has two major ongoing Kyprolis clinical trials: Focus and Aspire. Aspire is a Phase 3 clinical trial with an endpoint of progression-free survival to remain on the market. (A patient with progression-free survival is cancer-free at that time.) Final results for Aspire are expected in 2014. The other trial, Focus, should end a little earlier, but also will have a final read-out in 2014. It has always been viewed as risky by investors and analysts because it compares Kyprolis to "best supportive care," meaning the treatment regimen is left up to the individual doctor. So the control arm is not truly controlled.