Pfizer is in advanced talks to acquire U.S. cancer drug company Medivation for close to $14 billion, as it seeks to boost its oncology portfolio, people familiar with the matter said on Sunday.

Pfizer has agreed to pay a little more than $80 per share for Medivation, one of the people said, a substantial premium to the $52.50 offer for Medivation that France's Sanofi made in April, which eventually resulted in the company putting itself up for sale. Medivation shares ended trading in New York on Friday at $67.16.