Onyx Pharmaceuticals Inc has given potential buyers, including Amgen Inc, access to trial data on its new cancer drug, removing a key hurdle that was holding up deal talks, according to three people familiar with the matter.

The company's attempt to sell itself for around $9.5 billion hit an impasse in recent weeks after lead bidder Amgen sought trial data about blood cancer drug Kyprolis - something that Onyx was reluctant to share, Reuters reported last week.

Onyx provided the information this week to Amgen and other parties involved in the sale process, and is now waiting for a firm offer, the people said on Wednesday. Discussions could still fall apart and there is no guarantee a deal will happen, they cautioned.

All the people were not authorized to speak with the media and asked not to be identified. Representatives for Onyx and Amgen declined to comment.

(Reporting by Soyoung Kim in New York; Editing by Tim Dobbyn)