NEW YORK ( TheStreet) -- Amgen ( AMGN), the world's largest biotechnology company by sales, is nearing a $10.5 billion deal to buy Onyx Pharamaceuticals ( ONXX), according to news reports. An announcement of a deal could be made as soon as Monday, The New York Times reported Saturday, citing unidentified "people briefed on the matter." But " the talks could still fall apart before getting to the finish line," The Wall Street Journal reported Saturday, citing an unidentified person familiar with the matter. If the deal -- said to be worth $125 a share for Onyx shareholders -- is completed, Amgen would gain full rights to Kyprolis, a new drug to treat multiple myeloma, Reuters reported. The drug could reach peak sales of more than $2 billion a year, the news agency said, citing analysts. A spokesman for Amgen told TheStreet.com that his company had no comment. A similar response was received from a spokeswoman for Onyx.