Spark Therapeutics announced a licensing agreement Monday with a Watertown, Mass., biopharma firm for a "synthetic vaccine particles" technology to use with up to five gene therapy targets, including FVIII for hemophilia A.

Under terms of the deal, valued at as much as $460 million, Spark, spun out of Children's Hospital of Philadelphia, will pay an initial $10 million to Selecta Biosciences Inc. and buy $5 million of Selecta's common stock.

Selecta said its synthetic vaccine particle (SVP) technology could create a new paradigm in immunology and a novel approach to selectively target the body's immune system to treat and prevent rare and serious diseases.

Spark agreed to pay Selecta an additional $5 million in cash and to buy an additional $10 million of Selecta's stock within 12 months of the agreement's signing. Selecta will be eligible for as much as $430 million in milestone payments for each gene therapy target covered in the agreement.

The agreement does not apply to Spark's development programs in inherited retinal diseases, or the company's ongoing clinical trial in hemophilia B with Pfizer Inc.

Selecta will continue to use its technology for its proprietary gene therapy efforts, including a licensing agreement with Massachusetts Eye and Ear, a specialty hospital in Boston.

Selecta's nanoparticle technology, which is in preclinical testing in gene therapy, could enable repeat dosing and extend the reach of gene therapy to diseases that require higher doses, said Spark CEO Jeffrey Marrazzo.

Spark also announced Monday that John Furey has been hired to a new position of chief operating officer. Furey will be responsible for global commercial operations, medical affairs, technology development, and technical operations.