Pfizer Inc has agreed to acquire US cancer drug company Medivation Inc for close to $14 billion, as it seeks to boost its oncology portfolio.

Pfizer agreed to pay $81.50 per share for Medivation, a substantial premium to the $52.50 offer for Medivation that France’s Sanofi SA made in April, which eventually resulted in the company putting itself up for sale.

Reuters reported earlier this week that Pfizer, Sanofi, Merck & Co Inc., Celgene Corp and Gilead Sciences Inc. had submitted expressions of interest to acquire Medivation.

The strong acquisition interest in the San Francisco-based company illustrates how demand for new cancer treatments, which can possibly add years to patients’ lives, could spell billions of dollars in revenue to the companies that own them.

The strong acquisition interest illustrates how demand for new cancer treatment could spell billions of dollars in revenue

The deal is expected to be paid for by Pfizer in its entirety, or at least mostly, with cash, sources said.

Pfizer, whose oncology offerings include breast cancer drug Ibrance and several other promising immuno-oncology products, is now set to get access to Medivation’s successful prostate cancer drug Xtandi, as well as Talazoparib, another breast cancer treatment under development by Medivation.

Medivation earlier this year rejected two acquisition offers from Sanofi, the latest for $58 per share in cash and $3 per share in the form of a contingent value right relating to the sales performance of Talazoparib.

However, Medivation agreed in July to share confidential information with potential buyers after Sanofi agreed to drop a campaign to oust Medivation’s board of directors.

In its second-quarter earnings call this month, Medivation reported double-digit year-over-year growth for Xtandi, affirming the company’s expectations of over 50 per cent revenue growth for 2016.

Medivation also cited positive late-stage data for Talazoparib, a drug the company believes will account for a significant part of its long-term value.