Pfizer has finalized a licensing deal with Hong Kong-listed 3SBio for global rights to cancer drug SSGJ-707.

The US$1.25 billion upfront payment secures exclusive rights outside China, while Pfizer will pay up to US$150 million for rights within mainland China.

The deal, first announced in May, is the largest single-drug agreement in China’s biotech sector.

Pfizer will also invest HK$785 million (US$100 million) in 3SBio for a 1.3% equity stake, acquiring 31.1 million new shares at a 17% discount.

After the announcement, 3SBio’s shares dropped 6.41% to USHK$28.45.