Chiron Corp. has added another piece to its growing gene therapy franchise, signing a deal to gain access to Progenitor Inc.'s nonviral delivery and expression system for certain cancers, a specific cardiovascular indication and infectious diseases.

CHIR's in-house efforts in gene therapy began in December 1991 with the merger of CHIR and Cetus Corp., with targets from CHIR and Cetus and vectors from Cetus. Since then, the Emeryville, Calif., company has entered into four gene therapy deals, with Viagene Inc. (VIGN), Progenitor, Ribozyme Pharmaceuticals Inc. and Onyx Pharmaceuticals. The VIGN deal provides viral vectors and prodrug technology, the Ribozyme deal provides targeting, Onyx provides targets, and now Progenitor