Spark Therapeutics has gained exclusive worldwide rights to Selecta Biosciences’ Synthetic Vaccine Particles (SVP™) platform and exclusive options for up to four additional undisclosed genetic targets, through a deal that could generate up to $460 million-plus for Selecta, the companies said today.

Selecta’s immune tolerance SVP is intended to suppress the formation of neutralizing antibodies to an adeno-associated virus (AAV) capsid when used in combination with gene therapies, without altering the therapeutic profile of the gene therapy. SVP will be co-administered with gene therapy targets that include Factor VIII for hemophilia A, Selecta and Spark said.

“Selecta’s nanoparticle technology, which is undergoing preclinical testing in gene therapy, may prevent formation of neutralizing antibodies, and thus potentially enable redosing up to an optimal therapeutic profile by extending the reach of gene therapy to diseases that require higher doses or more extensive transduction of target cells than may be achieved through one-time dosing,” Spark Therapeutics CEO Jeffrey D. Marrazzo said in a statement.

Should the technology prove successful, Marrazzo added, SVP co-administered with a gene therapy may enable repeat dosing of AAV gene therapies in both adults and pediatric patients, potentially minimizing the risk of a T-cell immune response to the capsid.

SVP is a flexible nanoparticle platform designed to incorporate a wide range of antigens and immunomodulators, allowing SVP-based products either to induce antigen-specific tolerance or activate the immune system. Selecta aims to apply its SVP immune modulating platform—including SVP-Rapamycin—to develop and commercialize biologics capable of mitigating the formation of antidrug antibodies (ADAs).

Selecta uses SVP-Rapamycin to enhance efficacy and safety of therapy in proprietary programs that include SEL-212, the company’s lead Phase II clinical program in chronic refractory gout, and two gene therapies programs for genetic metabolic diseases.

Under the companies’ licensing agreement, Spark Therapeutics agreed to pay Selecta an initial $10 million cash and purchase $5 million of Selecta’s common stock. Within 12 months of the agreement’s signing, Spark Therapeutics agreed to pay Selecta an additional $5 million cash and purchase $10 million of Selecta common stock.

Selecta will be eligible for up to $430 million in milestone payments for each target—including up to $65 million based on Spark Therapeutics achieving development and regulatory milestones and up to $365 million for commercial milestones.

In addition, Spark Therapeutics agreed to pay Selecta tiered mid-single to low-double-digit royalties on worldwide annual net sales of any resulting commercialized gene therapy.

The licensing deal does not affect other ongoing development programs of Spark Therapeutics or Selecta, the companies added.