Takeda has signed a deal potentially worth $320 million with the USA’s Cell Genesys which will see the Japanese drugmaker get access to the latter’s late-stage prostate cancer treatment GVAX.

The two firms will develop and market the immunotherapy, which is currently in Phase III trials, and Takeda is paying Cell Genesys $50 million upfront for exclusive worldwide commercial rights to GVAX. Additional milestone payments could reach $270 million related to regulatory approval and commercialisation in the USA, European Union and Japan, and the California-based firm will also be entitled to flat double-digit royalties.

Cell Genesys will be responsible for the manufacture and supply of the product and will retain rights to co-promote GVAX in the USA, while Takeda has agreed to cover all future development and commercialisation costs.

Cell Genesys’ chief executive Stephen Sherwin described the deal as one of the most important in the firm’s history and the firm’s shares have surged accordingly. He added that he is glad to have the opportunity to work with the company that pioneered “the world’s leading prostate cancer drug”, ie Lupron (leuprorelin), “and hope to build on that success with GVAX”.

The drug is being studied in two Phase III clinical trials for advanced prostate cancer and final results from the first, called VITAL-1, are expected in the second half of 2009. Cell Genesys is targeting the completion of enrollment for VITAL-2 with approximately 600 patients in the first half of next year.

Phase II trials of GVAX immunotherapies for pancreatic cancer and for leukaemia are currently underway, as is a Phase I study of CG0070, an oncolytic virus therapy for bladder cancer. However these compounds are not included in the Takeda link-up.