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iStock, bo feng Some 200 rare disease therapies are at risk of losing eligibility for a pediatric priority review voucher, a recent analysis by the Rare Disease Company Coalition shows. That could mean $4 billion in missed revenue for already cash-strapped biotechs. More than $4 billion in reinvestment dollars will be left on the table if the rare pediatric disease priority review voucher program is not reinstated this week after having lapsed in December 2024. That’s according to a recent impact report issued by the Rare Disease Company Coalition. “That foregone value is very significant, particularly for small and emerging biotechs that operate on very tight margins and for patients who already have such limited treatment options,” Stacey Frisk, executive director of the Rare Disease Company Coalition (RDCC), told BioSpace , adding that 95% of rare diseases currently have no targeted treatments. Under the priority review voucher (PRV) rare disease program, which began in 2012, a sponsor files for the FDA’s Rare Pediatric Drug Designation. Then, if that drug is approved, the FDA grants a PRV, which can expedite the drug review timeline from 12 months to around 6 months. The vouchers can be bought and sold. At a going rate of around $150 million when the program sunset at the end of 2024, PRVs have provided a critical fundraising tool for tiny rare disease biotechs—money that often goes back into the rare disease pipeline. Now, at least a chunk of that funding is in jeopardy. An RDCC analysis of the rare disease pipeline showed that 200 therapies are at risk of losing eligibility for a PRV if the program is not reauthorized. Assuming that 37 of these therapies are likely to be approved without a PRV attached, Frisk said, “what that translates into is an estimated $4 billion in lost reinvestment potential.” Key legislation—dubbed the Mikaela Naylon Give Kids a Chance Act of 2025—passed the House on Thursday as part of a $1.2 trillion spending bill aimed at keeping the U.S. government open. It comes before the Senate this week. “We saw a really clear signal from the administration that they want Congress to act quickly to reauthorize the PRV program,” Frisk said, pointing to an email from Gary Andres, assistant secretary for legislation at the Department of Health and Human Services (HHS), to Senate Majority Leader John Thune advocating for the program. “HHS strongly supports reauthorization of the [rare pediatric disease] PRV program through September 30, 2029 as proposed in Section 5,” Andres wrote in the letter, which was viewed by BioSpace . Biotech has already been going through a tough time, underscored by funding challenges and the rapid emergence of Chinese innovation, Bo Cumbo, CEO of Solid Biosciences, a genetic medicines company focusing on rare neuromuscular diseases, told BioSpace . “The last five years for small startup companies, especially in the rare disease space, have been extremely challenging,” he said, “and the removal or the end of the priority review voucher will be just sort of that final straw that breaks the back of the rare disease companies.” By the Numbers First introduced in 2012 to encourage development of drugs for rare pediatric diseases affecting less than 200,000 people in the U.S., the PRV program has been highly successful. In 2024, the FDA handed out more rare pediatric PRVs than in any year since the scheme’s inception—in all, there have been 80, according to a BioSpace analysis . The highest price paid for a PRV was AbbVie’s $350 million purchase of United Therapeutics’ voucher in 2015. Earlier this month, Jazz Pharmaceuticals revealed the sale of a PRV attached to the August 2025 approval of glioma drug Modeyso for $200 million to an unnamed buyer. Rare diseases Priority Review Vouchers: By the Numbers A BioSpace analysis of all 80 priority review vouchers that have been handed out across the three FDA programs that offer them found that 2024 was the busiest year yet. Companies have disclosed spending $513 million on vouchers that were earned in 2024 so far. March 5, 2025 · 1 min read · Annalee Armstrong The PRV program began to wind down in December 2024, however, after Congress failed to pass legislation that would have renewed it. Under a temporary extension , rare disease drugs approved by Sept. 30, 2026, still qualify for a PRV, but without a renewal before then, no new vouchers will be granted. RDCC’s report showed that since the PRV program’s lapse, investors have grown more cautious. “Rare pediatric disease–focused companies are really having a more onerous time getting the capital they need to continue innovating in these disease areas that have really high unmet need,” Frisk said. A survey conducted by the organization revealed that for 85% of biotech executives, the PRV was a significant factor in their decision to pursue the development of rare pediatric disease assets; 35% have canceled or delayed programs in their pipeline since the program lapsed; and 50% expect further difficulties in accessing capital now that it has. “Right now, there’s a lack of predictability,” Justin To, CEO of skeletal dysplasia programs at BridgeBio, told BioSpace . “Without knowing whether or not Congress is going to reauthorize the program, that lack of predictability and that uncertainty really starts to kind of choke off investment in developing pediatric programs.” If Congress fails to reauthorize the program this week, the situation will only deteriorate, as biotech executives will have to make some tough calls—Cumbo among them. “If this rare disease voucher program is removed, you’re going to watch many of the smaller programs—[with] 10,000 or less patients—be cut, and they’ll be cut by someone like myself who is only thinking about how to survive as a company,” he said. “If you think about it, there are the haves and have-nots of disease states,” he continued. “There are markets that have shown to be very large where people could still put money to and they know that the risk versus reward can still be there.” By this calculation, Solid’s lead program, SGT-003 for Duchenne muscular dystrophy (DMD), which affects around 10,000 people in the U.S., would survive, Cumbo said. But for other rare diseases that are equally as fatal, “there has to be a lot of resources to sort of build the market. Those will be the disease states that are impacted.” Molybdenum cofactor deficiency (MoCD) Type A fits this description. In February 2021, BridgeBio won FDA approval for Nulibry, the first therapy to reduce the risk of mortality in patients with this ultra-rare disease. BridgeBio’s To credits the PRV program with being instrumental in bringing Nulibry to the market. “The reason why we were able to get that therapy approved was because of the pediatric review voucher,” he told BioSpace . While To noted that one of the company’s principles is to always put patients first, even if the economics don’t meet industry norms, “the PRV certainly makes it possible for us to develop medicines for ultra-rare diseases like we did for MoCD.” Ultimately, he said, “the PRV directly impacts how many of our rare-disease shots on goal we can fund and move into the clinic.” The program is also critical for earlier-stage companies like SynaptixBio, which launched in 2021 to tackle TUBB4a-related leukodystrophy, one of the world’s rarest diseases. “It’s difficult enough to get investment into early-stage companies,” SynaptixBio CEO Dan Williams told BioSpace , “but with rare diseases, where the market is much smaller, you really need to try everything you can to bring funding in.” The expedited regulatory pathway granted by a PRV or funds derived from its sale “derisk” rare disease drug development significantly, Williams said, allowing investors to come in at an early stage. Maintaining Momentum If the PRV program is reinstated this week, it would be a boon to a rare disease space that has seen significant regulatory momentum in recent months, making good on one of FDA Commissioner Marty Makary ’s first stated goals after taking office last year. In November 2025, the FDA introduced the plausible mechanism approval pathway for rare diseases, intended to expedite treatments “for products where a randomized trial is not feasible.” This followed the Rare Disease Evidence Principles framework in September that year to streamline the approval of therapies for ultrarare diseases, typically those affecting less than 1,000 people in the U.S. Rare diseases Rare Disease Experts See Futility in FDA’s Proposed Framework The FDA’s proposed Rare Disease Evidence Principles review process is a starting point for getting rare disease therapies across the finish line, but industry leaders say there are more concrete steps the regulator could take to help patients. September 22, 2025 · 5 min read · Dan Samorodnitsky Revenue estimates match the momentum. A recent report by ResearchAndMarkets.com has the orphan global drugs market reaching $611 billion by 2032—up from $247 billion last year. This reflects “ongoing regulatory evolution, targeted market incentives and increasing levels of investment,” according to the report’s authors. But failure to reauthorize the program will hobble this progress, experts who spoke with BioSpace agree. “Long term, if it doesn’t go through, I think we’ll see less financial institutes actually investing in rare diseases, and I think we’ll see less biotechs developing for rare diseases,” Williams said. “I think it’s going to really hit the rare disease industry quite hard.” .responsive-container { display: flex; flex-wrap: wrap; border: 1px solid #ededed; font-family: Helvetica, Arial, Sans-Serif; padding: 20px 20px 10px 20px; } .column-left { flex: 1; max-width: 45%; padding: 20px 20px 10px 20px; } .column-right { flex: 2; padding: 20px 20px 10px 20px; } @media (max-width: 768px) { .column-left, .column-right { max-width: 100%; flex: 100%; padding: 10px 0; } } Subscribe to ClinicaSpace! 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