SynaptixBio: Rare Disease Biotech Investment Rising in US After PRV Renewal, UK Lagging Behind

SynaptixBio, a UK-based biotech developing a therapy for the rare, deadly disease H-ABC, says investment in rare disease biotechs has increased in the US following reauthorization of the FDA's Rare Pediatric Disease Priority Review Voucher (PRV) program, while UK-based rare disease companies continue to lack an equivalent incentive.¹ The PRV program was signed into law in February 2026 and will remain in place until it comes up for review again in September 2029.¹ According to VC firm V-Bio, reauthorization of the PRV scheme "has restored financial certainty and sparked intense interest from large pharma" in the sector.¹

How does the Priority Review Voucher program work, and why does it matter for smaller biotechs?

A PRV is awarded to a company that receives FDA approval for a drug treating a rare pediatric disease, and it entitles the holder to an expedited, six-month FDA review of a future drug application, rather than the standard ten-month timeline.² Critically, PRVs are transferable: a company that earns one can sell it to another company, generating cash without requiring the seller to issue new equity, making it a source of non-dilutive capital.¹ PRVs have sold recently for between $150 million and $200 million, with recent examples including Jazz Pharmaceuticals' sale of a voucher for $200 million and Abeona Therapeutics' sale of a voucher for $155 million in May 2025, shortly after FDA approval of its gene therapy Zevaskyn.³

What did SynaptixBio's CEO say about the US-UK investment gap?

Dan Williams, PhD, chief executive officer of SynaptixBio, said, "The US dominates because the PRV program creates a highly valuable and, more importantly, tradable asset. VCs and private equity firms are far more willing to invest in rare disease biotechs simply because they provide a financial return on investment."¹ Williams added, "While the UK is known for high-quality science and innovation, it has seen a sharp contraction in biotech fundraising. Without an equivalent to the FDA PRV program, UK rare disease biotechs rely heavily on public markets, private investment, or acquisition by larger global pharma to secure capital."¹

What would help close the gap for UK rare disease biotechs?

The UK's Medicines and Healthcare products Regulatory Agency (MHRA) is currently consulting on a new regulatory framework intended to bring rare disease drugs to market more quickly, but Williams said that framework alone won't solve the underlying investment problem.¹ "It would be ideal if the UK could introduce a scheme similar to the PRV," Williams said. "With the proposed new framework we have everything in place to better manage the clinical trial and marketing authorisation process for rare disease therapies, but it stops there. Reducing regulatory and approvals timescales and costs can only be good for rare disease patients and their families, but adding this stronger incentive could transform the industry, making the UK a leading player in research and development in this key area."¹ He added that SynaptixBio still intends to conduct clinical trials in the UK to help inform later US trials, "but this all depends on raising further investment."¹

What is the broader scale of unmet need in rare disease?

Roughly 1 in 17 people will be affected by a rare disease during their lifetime, amounting to more than 3.5 million people in the UK alone, yet only around 5% of the approximately 10,000 known rare diseases have an approved treatment.¹ Around 80% of rare diseases are monogenic, caused by a mutation in a single gene, a characteristic that makes many of them more suitable for highly targeted treatment approaches such as gene silencing technologies.¹ SynaptixBio's own lead candidate is an antisense oligonucleotide designed to bind to and suppress the mutated messenger RNA that causes TUBB4A leukodystrophy, without altering the underlying gene itself.¹ The company's therapeutic assets remain in preclinical development as it works toward first-in-human clinical trials in accordance with GxP and Good Clinical Practice standards.¹

References

1. SynaptixBio Ltd. Investment in rare disease biotechs increasing since PRV scheme renewal, says leading biotech, but UK lagging. Company statement. SynaptixBio Ltd; August 11, 2026.
2. Rare paediatric disease voucher programme makes long-awaited US return. Pharmaceutical Technology. February 2026. Accessed August 11, 2026.
3. Abeona Therapeutics enters into agreement to sell Priority Review Voucher for $155 million. BiopharmaWatch. Press release. May 12, 2025. Accessed August 11, 2026.