Generation Bio said it closed a $100 million series B financing to advance to the clinic its first two therapeutics candidates using its GeneWave platform to develop a new class of genetic medicines with drug-like qualities.

Fidelity Management & Research Company led the round with Invus, Deerfield Management Company, Casdin Capital, Foresite Capital and Leerink Partners’ Affiliates.

Generation Bio’s GeneWave platform is developing gene therapies that can be titrated and re-dosed. It makes use of lipid nano-particles instead of viral vectors to deliver its closed-ended DNA. Closed-ended DNA, or ceDNA,  has the ability to move from the cytoplasm of the cell to the nucleus without the use of a viral vector.

Unlike viral vectors, which can only be used once because repeated dosing would trigger an immune response, Generation Bio says its platform allows for the ability to adjust dosing, repeat dosing, and to carry larger payloads for a wider array of genes as well as regulatory elements.

“We are delighted to have the support of this group of experts, long-term investors who share our vision to create a generation of people living unaffected by genetic disease,” said Geoff McDonough, president and CEO of Generation Bio. “This will be a critically important year for us as we develop the GeneWave platform and work towards our first development candidates to address rare diseases of the liver.

The company is initially focused on developing medicines for rare genetic diseases, including inherited metabolic disorders and lysosomal storage diseases, as well as emerging treatment areas where large numbers of patients cannot be addressed by current gene therapy approaches. Beyond the liver, the company has also demonstrated durable in vivo expression in muscle, the retina, and the central nervous system.