GlaxoSmithKline will pay up to $61 million to license, research and develop Adaptimmune Therapeutics' T-cell therapy to treat cancer.

GSK signed a collaboration deal in 2014 with the U.K. biotech, which has U.S. headquarters at the Navy Yard in South Philadelphia. On Thursday, GSK exercised its option to exclusively license the T-cell therapy, develop and sell it, the companies announced.

GSK, with headquarters in Brentford, England, employs about 5,000 in the Philadelphia area, including at the Navy Yard and in Upper Merion and Upper Providence, Montgomery County. Adaptimmune, which is based in Oxford, U.K., employs 106 at its U.S. headquarters at the Navy Yard.

"This is a very exciting day for Adaptimmune as GSK has exercised its option over our NY-ESO program earlier than originally planned," said James Noble, Adaptimmune's chief executive officer.

Axel Hoos, GSK senior vice president of oncology research and development, said data  presented at a medical meeting in June was "compelling" for the cell therapy to treat synovial sarcoma. GSK plans to explore its use "in multiple tumor types, and in combination with other cancer therapies," he said.

GSK will take responsibility now with the cell therapy in an ongoing study to treat multiple myeloma in combination with Merck & Co.'s Keytruda cancer treatment.

If the T-cell therapy is commercialized, GSK will pay additional undisclosed payments and royalties based on sales.