After rejecting Amgen's (AMGN) $8.7 billion buyout offer on Sunday and beginning the active pursuit of third-party bids, Onyx Pharmaceuticals (ONXX) was reportedly approached by a slew of drug giants, including Pfizer (PFE) and Novartis (NVS).

Onyx has attracted preliminary buyout interesting from “several large pharmaceutical companies,” including Pfizer and Novartis, according to a report by Reuters citing two people familiar with the matter.

The drug maker with a market value of roughly $9.5 billion and a suite of money-making cancer treatments on Sunday said it was “actively exploring” deals with other companies and confirmed that it had received interest from third parties, though it did not say from whom. 

Novartis told FOX Business it does not “comment on rumors or speculation.” Pfizer did not immediately return a request for comment.

Onyx rejected Amgen’s $120-a-share bid last weekend for not being in the best interest of shareholders, saying its expanded pipeline and two successful product launches have provided extra value to investors not calculated into the Amgen offer.

Shares of the South San Francisco-based company edged up about 2% to $133.81 in early trade.

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