Adaptimmune announced in a statement that it has entered a "strategic cancer immunotherapy collaboration" with GSK to "develop and commercialise novel cell-based therapies" in its lead clinical cancer programme.
The biotech firm, which is based in Oxford, southern England and Philadelphia, has had success in trials in using T-cells, the heavy weaponry of the immune system, to target cancer cells.
The GSK deal, worth the equivalent of 260 million euros could yield payments in excess of $350 million to Adaptimmune over the next seven years, according to the statement.
There would also be "significant" additional development and commercialisation payments in subsequent years, if GSK exercises all its options and milestones continue to be met.
Adaptimmune would also receive royalties ranging from single to double digits on net sales.
The statement added that trials in Adaptimmune's lead programme, in multiple myeloma, melanoma, sarcoma and ovarian cancer in the United States, are generating "encouraging" results. European trials are set to start shortly.
Monday's announcement meanwhile follows the collapse last week of US drugs giant Pfizer's $117-billion takeover offer for GSK's key British rival AstraZeneca.
It also comes after GSK agreed last month to sell its oncology business to peer Novartis for $16 billion and to buy the Swiss group's vaccines division.