(Reuters) - Gilead Sciences Inc (NASDAQ:GILD) said on Tuesday it would buy a 49.9% stake in privately held cancer immunotherapies developer Pionyr Immunotherapeutics Inc for $275 million.
The drugmaker said it has also secured the right to acquire the rest of Pionyr for a $315 million option exercise fee.
Pionyr's immuno-oncology product candidates, PY314 and PY159, have shown potential against solid tumors in animal studies and it plans to file applications with the U.S. Food and Drug Administration in the third quarter to begin human testing.
Gilead has been expanding its oncology portfolio. In March, the company announced a $4.9 billion deal for Forty Seven Inc, adding an experimental treatment that targets blood cancer.
The deal comes as Gilead is racing to expand the global supply of its antiviral drug remdesivir for use in COVID-19, a respiratory illness that has no currently approved treatments or vaccines.
Pionyr's shareholders are also eligible to receive up to an additional $1.47 billion in option exercise fees and future milestone payments.