Dec 6 (Reuters) - Summit Therapeutics Inc said on Tuesday it has signed a licensing deal worth up to $5 billion with China-based Akeso Inc for an experimental cancer therapy.

Summit said it would make an upfront payment of $500 million, and Akeso will be eligible for regulatory and commercial milestone payments of up to $4.5 billion. (Reporting by Leroy Leo in Bengaluru; Editing by Vinay Dwivedi)