SynaptixBio: ‘Huge moment’ for rare disease drug development as incentive scheme reauthorised, says leading biotech

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

The U.S. Senate on January 30th reauthorised the FDA’s Priority Review Voucher (PRV) programme, which incentivises rare disease drug development, and on Tuesday President Trump signed the bill, known as the Mikaela Naylon Give Kids a Chance Act, into law.

On December 1st last year, the House of Representatives passed the bill that reauthorised the programme, which had failed for various reasons to be reauthorised in December 2024, but it had stalled in the Senate due to unrelated federal budget issues.

Dan Williams, CEO at SynaptixBio, which is developing a drug to treat H-ABC, a rare, deadly, and currently incurable disease, says passing the bill is a huge moment for small biotechs developing rare diseases therapies.

He notes; “The PRV programme means smaller biotechs can see a way to financial security, having typically had to find investment during the long years of drug design and development.

“The very high cost of preparing for, and conducting, clinical trials adds to the financial challenge, and all the risk remains until a candidate drug is approved for the market.”

PRVs continue to attract high prices; in mid-January this year, Jazz Pharmaceuticals sold a PRV to an undisclosed buyer for $200 million.

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 addition to the Jazz Pharmaceuticals deal mentioned above, 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 last year, Abeona Therapeutics sold a PRV for $155 million that it had gained just two weeks earlier following approval of its gene therapy Zevaskyn.

SynaptixBio earlier in 2025 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.”

To find out more about SynaptixBio please visit https://www.synaptixbio.com/.