SynaptixBio, the only company licensed to commercialise a treatment for a rare, deadly disease, says the Priority Review Voucher scheme is a lifeline for smaller biotechs

On December 1st, the US House of Representatives passed a bill that reauthorises the Food and Drug Administration’s (FDA) priority review voucher (PRV) programme, which is designed to incentivise rare disease drug development.

The PRV program contains a ‘sunset clause’ that means it must be periodically reauthorised. In December 2024 this didn’t happen for various reasons,including debate over its effectiveness and concerns about high PRV prices. 

Dan Williams, CEO at SynaptixBio, which is developing a drug to treat H-ABC, a rare, deadly, and currently incurable disease, says the PRV program is a vital lifeline for small biotechs developing rare diseases therapies.

He notes; “Developing therapies for rare diseases is a moral imperative. Whilst individually rare, together millions worldwide are affected.

“The PRV scheme means smaller biotechs can see a meaningful return on the very high investment needed to develop and take a rare disease drug through clinical trials.”

When passed by the Senate, the bill, known as the Mikaela Naylon Give Kids a Chance Act, will be passed to President Trump for final sign-off. 

SynaptixBio currently holds two Rare Paediatric Disease Designations from the FDA, one for H-ABC and another for Isolated Hypomyelination – a rarer form of TUBB4A leukodystrophy. The company hope these will lead to the award of PRVs.

The original PRV scheme, which was designed to address neglected tropical diseases, was authorised by the FDA in 2007, then expanded in 2012 to include rare paediatric diseases.

PRVs are seen as highly valuable in the biopharma industry. They can cut the FDA’s drug application review time from 10 to six months.

In August 2024, Ipsen received $158 million for a PRV it was awarded following approval of the rare disease drug Sohonos a year earlier.

In May this year, Abeona Therapeutics sold a PRV for $155 million that it had gained just two weeks earlier following approval of its gene therapyZevaskyn.

SynaptixBio earlier this year chose its lead candidate drug, an antisense oligonucleotide (ASO), for taking forward into clinical trials; ASOs are a form of gene silencing technology, they stop mutated genes forming toxic proteins. Critically, they don’t alter the gene itself.

Dan Willimas concluded; “Structurally, it has been the smaller biotechs that have worked on rare diseases therapies. Bigger pharma companies are much more inclined to invest in mass-market drugs.

“However, once a smaller biotech’s candidate orphan drug has passed toxicology tests and proceeded to clinical trials, Big Pharma’s strengths in navigating regulatory approvals, making deals with Governments and health services, and manufacturing, then prove vital.

“It may be that there is obvious synergy here; Big Pharma doesn’t face the high investment risk of developing a rare disease drug, and the smaller biotech has a natural target for selling its PRV.”