Vir Biotechnology's stock surged 5.52% in the after-hours session following the announcement of a significant global strategic collaboration.

The biotech company has entered into a partnership with Japan's Astellas Pharma to develop and commercialize VIR-5500, Vir's experimental treatment for advanced metastatic prostate cancer. Under the deal, Vir will receive $335 million in upfront and near-term payments, including $240 million in cash and a $75 million equity investment at a 50% premium.

Additionally, Vir Biotechnology is eligible to receive up to $1.37 billion in development, regulatory, and sales milestone payments, plus double-digit royalties on sales outside the United States. Astellas will lead commercialization in the U.S. with Vir retaining an option to co-promote, while Astellas obtains exclusive rights for all other markets.