(Reuters) -Merck has licensed an early-stage cancer drug from a China-based biotech in an up to $3.3 billion deal, two months after a similar therapy from Summit Therapeutics outperformed its blockbuster Keytruda in a late-stage trial in the country.

Merck & Co. licensed an experimental cancer antibody from a closely held Chinese company in a deal worth $588 million upfront, plus as much as $2.7 billion in milestone payments.