Arimoclomol

iStock, Orla Congress did not reauthorize the rare pediatric disease priority review program at the end of 2024. Advocates say the ripple effect is already being felt across biopharma. The FDA has never handed out more priority review vouchers than it did in 2024. Depending on who you ask, that’s a sign that the program is working or that pharma is reaping huge benefits in a quid pro quo situation of the government’s own making. But now rare disease biotechs have been left scrambling, as Congress did not renew the rare pediatric disease portion of the program at its end of year deadline despite bipartisan support. “The impact on the rare disease drug developers and the investment community [is] already being felt because of the destabilizing effect of the failure to reauthorize the program prior to its expiration,” Stacey Frisk, executive director of the Rare Disease Company Coalition, told BioSpace in an interview. Her group is lobbying for a renewal to be tacked on to congressional efforts to address a looming March 14 budget deadline. “So really, the timeline is as soon as possible.” The priority review voucher (PRV) rare disease program, which began in 2012, had unanimous renewal support from the 118th Congress, which ended on Jan. 3, according to Frisk. The program passed the House without issue and was listed among the priorities for the resolution to avoid a government shutdown. But the health programs that included the PRV program—which had already begun to sunset—were stripped from the continuing resolution at the last minute. Despite the bipartisan support, the PRV program “got caught” as Congress’ timelines and priorities changed at the last minute, Matthew Winton, chief operating officer of Inozyme Pharma and a rare disease advocate , told BioSpace . A bill called the Give Kids a Chance Act of 2024 has now been proposed to get the PRV program moving again, as Congress works to avoid the shutdown. “Time is . . . sort of running out,” Winton said. “We need action on this immediately to continue the program but also continue investment in these pediatric rare diseases.” The FDA notified drugmakers in the fall that, absent the renewal passing, the agency would have to stop handing out the coveted fast-pass vouchers, which expedite the drug review timeline from 12 months to about 6 . The vouchers can be bought and sold, which provides a valuable fundraising boost for tiny rare disease biotechs. The current going rate on the open market is $150 million, the price Zevra Therapeutics earned just last week for its voucher that was granted from the September 2024 approval of Miplyffa. According to Winton, the cost of PRVs has risen to this rate as companies foresee the end of the program. Without renewal, the FDA began sunsetting the program as of December 20, 2024. The agency cannot award any new vouchers unless the drug already had the rare pediatric disease designation. If Congress does not act, companies with existing designations will only have until September 30, 2026, to get their drugs approved in order to earn a voucher. Already, companies with the rare pediatric disease designation for drugs in development are reeling, with many starting to warn investors in Securities and Exchange Commission filings that they may never get their coveted vouchers despite working for years to position for one. Winton said that companies make decisions to develop a drug years in advance, so having the rug pulled out suddenly due to a policy change can halt external investment. “With that uncertainty, you’re going to get a slowdown in decision making. You’re going to get a slowdown in people investing in R&D programs,” Winton said. See BioSpace ’s full analysis here . Quid Pro Quo The industry has spent at least $513 million on buying vouchers that were earned in 2024, although more could have been sold without public disclosures. These non-dilutive proceeds are often used by smaller companies to bolster their overall clinical programs. In a recent case that underscores the stakes, bluebird bio fought hard to get one for its sickle cell disease gene therapy Lyfgenia, which was approved in December 2023 . Bluebird had already lined up a buyer before it even received the approval, according to SEC documents dated October 2023. Novartis agreed to pay $103 million for the voucher if it were granted. While bluebird was granted rare pediatric disease designation in May 2020 for the treatment, the FDA did not hand out the coveted voucher. Bluebird appealed and was ultimately rejected three times. The agency did, however, hand one out to Vertex Pharma for rival gene therapy Casgevy, which was developed with CRISPR Therapeutics and approved on the same day as Lyfgenia . This unsuccessful effort was cited in bluebird’s recent announcement that it would sell itself to private equity firms in a deal valuing the gene therapy maker at just $30 million. Bluebird did not have enough cash to operate past the first quarter but had spied positive revenue later in the year. Eleven of the valuable trading cards were handed out to biopharma companies over 2024, across the three different programs that offer the vouchers. For the rare disease program specifically, indications that benefitted include sickle cell, Niemann-Pick type C, Duchenne muscular dystrophy and glioma, among others. With the pediatric rare disease program sunset announced, the FDA has handed out two already this year to Novo Nordisk for hemophilia A therapy Alhemo and Neurocrine Biosciences for congenital adrenal hyperplasia drug Crenessity. There are two other ways to get one beyond the rare disease program: through the development of drugs for tropical disease or a biological threat, such as COVID-19. Four have been awarded since the pandemic began for COVID-19: to Moderna, BioNTech, Pfizer and Gilead for their vaccines and antivirals. Neither of these programs are impacted by Congress’ recent actions, and so far, the FDA has granted one voucher under the tropical disease program this year: to Bavarian Nordic for its chikungunya virus vaccine Vimkunya. Bavarian Nordic has already indicated plans to sell the voucher “when appropriate.” Opponents of the voucher programs say the fast passes are not doing their job to expedite the approval of drugs to help fill unmet needs in the rare and tropical disease communities. In a December 2024 paper , U.K. researchers Piero Olliaro and Els Torreele called the program “a misconceived quid pro quo, whereby much is given for little public health return, promoting and rewarding monopoly pricing of high-revenue products, with no strings attached—which indeed makes it attractive to pharmaceutical companies and investors.” Bigger companies that earn or buy the vouchers use them to skip the line at the FDA for any drug they want. These vouchers are hard to track, as the companies do not have to report exactly where they got the voucher from when they use them. The FDA in recent years has occasionally posted Federal Register documents noting that a voucher was used for a particular drug, but these documents do not indicate where the voucher came from. From various records, it’s clear that many major blockbuster drugs of recent years have used these hall passes, from Eli Lilly’s Mounjaro, to AbbVie’s Rinvoq to Gilead’s portfolio of HIV meds and many more. In mid-February, Alnylam Pharmaceuticals cashed one in for a speedy review of Amvuttra in ATTR amyloidosis with cardiomyopathy, an indication that is one of the hottest market battles at the moment with offerings from Pfizer and BridgeBio now available. Vertex Pharmaceuticals did the same in July 2024 for cystic fibrosis triple med Alyftrek, receiving an FDA nod less than six months later, in December 2024. Novartis has by far been the most frequent patron of the fast passes, with as many as eight bought or earned over the years. The company has used the passes on Mayzent, Beovu, Kesimpta, Fabhalta and Kisqali, according to records. Gilead has spent as much as $621 million on known purchases of priority review vouchers. Olliaro and Torreele argue that the program does not actually encourage drug sponsors to ensure the availability of the medicines that get approved under the program, especially for tropical diseases. For instance, the makers of tuberculosis therapies Sirturo and Dovprela, a medicine that was approved under the tropical disease program as pretomanid, have been criticized for keeping the prices for the therapies too high to help in countries with a high tropical disease burden. Sirturo is manufactured by Johnson & Johnson while Dovprela (previously pretomanid) was developed by the TB Alliance . Frisk and Winton are aware of the criticisms but say that the rare disease program is working. You just have to look at the ramp up of drugs that have received a voucher over the years, with more handed out recently. That means that more companies are making these drugs and more rare diseases are getting new options for patients. As for the criticism of a handout for Big Pharma, Winton says this is a tax neutral program. No taxpayer funds are being given to these companies; it’s simply a market-based solution that ultimately helps smaller companies do what they do best: develop rare disease drugs for smaller populations. “Some of these drugs may not be developed or invented at all” without the voucher program, Winton said. “These [vouchers] are not necessarily going to the 17th, 18th statin—not that there’s anything wrong with that—but these are also going to feed the cycle of innovation and bringing drugs to patients in the U.S. who have no other options.” Planning Funerals One pediatric rare disease that has particularly benefitted is Duchenne muscular dystrophy, which has had seven drugs approved under the PRV program, including four from Sarepta Therapeutics. Each time, Sarepta sold its voucher and used the funds to continue its clinical programs. Another rare disease that now has multiple options is spinal muscular atrophy. Winton previously worked at Biogen as head of the SMA franchise, where he oversaw work on Spinraza, which received a PRV in March 2017. “That disease state has completely changed. You were used to planning funerals. And now you’re celebrating birthdays and you’re celebrating graduation into high school,” Winton said. “That’s an amazing success story.” These patients now have several different modalities to choose from, including Novartis’ gene therapy Zolgensma and Genentech’s Evrysdi, both of which received priority review and were granted vouchers at approval. These seminal approvals of complex technologies like gene therapy have also helped fuel other innovations in the modality, which is another legacy of the PRV program, Winton noted. Similarly, Biogen advanced its antisense oligonucleotide technology with Spinraza, which earned a voucher in March 2017 and was sold for $103 million last year . “When you talk to patients, when you talk to the rare disease community, the one thing they always say is ‘move faster.’ The one thing they don’t have is time,” Winton said. “The message we always take away when we talk to them is try to work hard or hurry up. This program does that. It speeds up our ability to get drugs to market. It speeds up our ability to do more research.” About the data: BioSpace compiled the list of priority review vouchers through dozens of sources, including the FDA, Federal Register, SEC, GAO, company reports, news articles and more. Still, the list may not be comprehensive, as some PRV transactions go unreported.

iStockphoto/ Olivier Le Moal ITF, IntraBio and Orchard are among the companies that have won FDA nods in the past year for Duchenne muscular dystrophy, Niemann-Pick disease type C, metachromatic leukodystrophy and more. Rare Disease Day, which falls at the end of February each year, is an opportunity to take stock of advances in this space, as well as the many remaining gaps in care and treatment. Defined as diseases that affect fewer than 200,000 people in the U.S., rare diseases collectively afflict about 350 million people worldwide, according to the National Organization for Rare Disorders . An estimated 7,000 of these conditions have been identified, and more than 90% of them have no FDA-approved treatment. Yet progress toward developing such treatments continues, particularly among smaller companies. Here are five rare diseases that have seen drug approvals since last year’s Rare Disease Day. Duchenne Muscular Dystrophy Duchenne muscular dystrophy (DMD) is a relatively common rare disease, affecting about one out of every 3,600 baby boys. This X-linked genetic disease affects the dystrophin protein, a component of muscle, and causes progressive weakening of skeletal and heart muscle. Families affected by DMD saw a spate of treatment approvals in 2023 and 2024, including Sarepta Therapeutics’ Elevidys and Catalyst Pharmaceuticals’ Agamree. The most recent was Duvyzat (givinostat), a small molecule therapy marketed by ITF Therapeutics. It targets histone deacetylases, enzymes that modulate gene and protein expression in the muscle. “Deregulation of HDACs is a major consequence of the lack of dystrophin associated with DMD,” Matt Trudeau, head of ITF, told BioSpace in an email ahead of the FDA decision in March 2024. “We believe givinostat’s mode of action has the potential to inhibit HDAC pathological overactivity and thereby impact the cascade of events leading to muscle damage which, in turn, may counteract disease pathology and slow muscle deterioration.” In the Phase III Epidys trial , givinostat met the primary endpoint of a change in the four-stair climb assessment from baseline to 72 weeks. Italfarmaco, the parent company of ITF which developed the drug, also reported that it showed “favorable outcomes” in key secondary measures, including on the North Star Ambulatory Assessment (NSAA), a scale that measures motor function skills. On the NSAA, patients treated with the new drug saw less worsening compared to placebo after 18 months. Givinostat was generally well tolerated, with no treatment-related severe or serious adverse events. Metachromatic Leukodystrophy Metachromatic leukodystrophy (MLD) is a metabolic disease that affects one in every 100,000 live births. It is caused by a mutation in the arylsulfatase-A ( ARSA ) gene, which codes for an enzyme that breaks down sulfatides, and is characterized by a pathological build-up of sulfatides in the brain, liver, kidneys, spleen and other body parts. Over time this buildup can lead to organ damage and neurological issues, and patients often experience motor, behavioral and cognitive problems, as well as seizures. Most patients die within five years of disease onset. The FDA approved the first therapy for early juvenile or early symptomatic forms of the disease, Lenmeldy (atidarsagene autotemcel), in March 2024. The gene therapy, marketed by Orchard Therapeutics, uses a patient’s own stem cells to deliver a functioning copy of the ARSA gene. Lenmeldy was also approved by the European Union in December 2020 , where it is marketed as Libmeldy. The FDA’s approval of Lenmeldy is backed by data from two single-arm, open-label trials enrolling a total of 37 pediatric MLD patients. Over a median follow-up of 6.76 years, Lenmeldy led to significantly better overall survival compared with natural history data. The gene therapy also preserved motor and cognitive function in late-infantile MLD patients. Lenmeldy’s most common adverse events were febrile neutropenia, stomatitis, respiratory tract infections and rashes. WHIM Syndrome Fewer than 1,000 people in the U.S. have been diagnosed with WHIM syndrome, according to the NIH. The condition’s name is an acronym of the four characteristics of the disease: warts, hypogammaglobulinemia (low antibody levels), infections and myelokathexis (a white blood cell disorder). The syndrome is caused by mutations in the chemokine receptor ( CXCR4 ) gene that increase the activity level of the resulting protein. In April 2024, the FDA approved X4 Pharmaceuticals’ Xolremdi (mavorixafor) as the first targeted treatment for WHIM. Xolremdi is an oral CXCR4 antagonist that draws white blood cells from the bone marrow into the blood to improve immune deficiencies. It is approved for patients 12 and older. Phase III results from the 4WHIM trial of Xolremdi showed a 60% reduction in annualized infection rate compared to placebo; trial participants had less than one infection per year compared with 4.5 for the placebo group. Teresa Tarrant, an associate professor at Duke University’s School of Medicine and lead investigator of the 4WHIM trial, told BioSpace last year that previous treatments for the disease were only supportive. “I think that for a lot of patients, the idea that there is a targeted therapy . . . something that is directly correcting the underlying problem for the individual, I think that gives them a lot of hope, a lot of optimism,” Tarrant said. “I think WHIM is going to be a poster child for rare diseases and the ability where we’re at now in modern medicine to design therapies to treat underlying genetic disorders.” Niemann-Pick Disease Type C Afflicting approximately one in every 150,000 people , Niemann-Pick disease type C (NPC) is an ultrarare lysosomal storage disease that progressively impairs patients’ physical and cognitive function. It is caused by mutations in the NPC1 and NPC2 genes that hinder the body’s ability to clear cholesterol and other lipids from inside cells, leading to their pathologic build-up in the brain and other crucial organs. NPC affects patients’ speech, motor and swallowing functions. According to the FDA , patients with NPC typically live only up to around 13 years of age. September 2024 saw not one, but two approvals of therapies for NPC. The first, Zevra Therapeutics’ Miplyffa (arimoclomol), is an oral drug approved for patients 2 years and older that is intended to be used alongside miglustat , a small molecule approved to treat the neurological manifestations of NPC. According to the company , Miplyffa activates transcriptional factors, resulting in the upregulation of coordinated lysosomal expression and regulation (CLEAR) genes. In a clinical trial, Zevra found that Miplyffa plus miglustat stopped disease progression during 12 months of treatment, decreasing patients’ scores on an assessment of NPC symptom severity. Meanwhile, patients treated with miglustat alone experienced a progression in symptoms. The second approval was for IntraBio’s Aqneursa (levacetylleucine) in adults and children weighing at least 15 kg. According to the company, it is not clear what Aqneursa’s target is, but it may activate cerebral glucose metabolism in the cerebellum and thus boost cerebellar activity. A randomized, double-blinded and placebo-controlled crossover study found that during the 12-week period that patients were treated with Aqneursa, they showed better functional performance as measured by a score that assesses their gait, sitting, stance and speech. The drug was well-tolerated, with common side effects including vomiting, abdominal pain, difficulty swallowing and upper respiratory tract infections. The drug’s label includes a warning for embryo-fetal harm if used during pregnancy. The back-to-back NPC approvals highlighted the FDA’s commitment to supporting the development of innovative therapies for rare diseases, Janet Maynard, director of the agency’s Office of Rare Diseases, Pediatrics, Urologic and Reproductive Medicine, said in a statement . Cerebrotendinous Xanthomatosis Cerebrotendinous xanthomatosis (CTX) is a very rare metabolic disease, affecting just one in a million people globally . It is characterized by the inability to break down certain types of cholesterol and other lipids, leading to their toxic accumulation throughout the body, particularly in the brain and connective tissues. Patients with CTX suffer from neurological abnormalities in early adulthood, including seizures and problems with movement and speech. Just last week, CTX got its first approved drug with the FDA’s greenlight of Mirum Pharmaceuticals’ oral therapy Ctexli (chenodiol). CTX is caused by mutations in the CYP27A1 gene, which codes for an enzyme that breaks down cholesterol into bile acids, and Ctexli replenishes the body’s levels of bile acids. This reduces the build-up of the toxic metabolites that cause the disease. Mirum’s application for approval of the drug included data from the Phase III RESTORE study, a June 2024 readout of which showed the drug could lower bile alcohols “with high statistical significance,” the biotech said at the time. Ctexli’s benefit was 20-fold greater in magnitude than that of placebo. The most common adverse events associated with Ctexli include hypertension, muscle weakness and diarrhea, and its label includes precautions about potential liver toxicity.