GlaxoSmithKline (GSK) has signed a deal with a UK biotech company to develop new cancer drugs.GSK will pay Adaptimmune as much as $350m over the next seven years.Adaptimmune and GSK will work together to develop cell-based cancer therapies that involve re-engineering patients' white blood cells to help fight tumours. The move comes less than six weeks after GSK agreed to sell its existing oncology products to Novartis for $16bn. At the time, the company said it did not have enough scale in the oncology market to compete effectively with its existing treatments for skin cancer, breast cancer and leukaemia. The market for cancer therapy is currently dominated by Swiss giant Roche, Germany's Merck, America's Bristol-Myers Squibb and GSK's compatriot AstraZeneca.RD