Scientific advances in gene and cell therapy are moving fast. CRISPR-based therapies are being developed in record time to help children with life-threatening conditions. At the same time, new delivery approaches are making it easier to target the brain for neurological diseases. As the FDA and other regulators shift leadership and strategy, the entire landscape of drug development may be changing—especially for next-generation treatments.
But what does this rapid progress mean for Dravet syndrome and other rare conditions?
In this blog, I’ll reflect on my key takeaways from the 2025 American Society of Gene and Cell Therapy (ASGCT) meeting in May and the recent FDA Roundtable on Gene and Cell Therapies held in June and how they may relate to Dravet syndrome in the future.
Personalized Gene Editing: No Longer Just a Dream
Last week’s Decoding Dravet blog highlighted a remarkable case: a young child receiving a life-saving, personalized CRISPR therapy developed at unprecedented speed. While this case is unique—and such rapid development won’t be the norm for most patients—it’s a sign of what’s possible.
The exciting part? These breakthroughs are laying the groundwork for a future where many more people with genetic diseases, including Dravet syndrome, may benefit from therapies designed to correct the root cause of their disorder.
A Faster Path Without Sacrificing Safety
At the ASGCT Meeting, Dr. Fyodor Urnov, a pioneer in bringing CRISPR from the laboratory bench to patients, shared data showing that faster development doesn’t necessarily compromise safety or effectiveness. He also discussed a potential “platform” approach—where gene-editing tools can be adapted for individual patients using shared safety data. This model could dramatically reduce the time and cost to bring therapies to clinic, even for rare conditions where each patient may require a slightly different solution. Dr. Urnov also had the opportunity to speak at the subsequent FDA Cell & Gene Therapies Roundtable, where he urged the very receptive FDA leadership to consider new platform approaches in their regulatory decisions, enabling cures to be developed and brought to market more rapidly for patients with life-altering genetic diseases.
The Challenge—and Promise—for Dravet Syndrome
Gene editing for Dravet syndrome faces a few big hurdles:
- The SCN1A gene is large, making full replacement challenging.
- Over 1,000 different mutations in SCN1A can cause the disease, and most patients have unique variants.
That makes a one-size-fits-all gene editing therapy unlikely. But a platform-based approach might allow for multiple individualized therapies to be evaluated and approved under a single framework—greatly expanding what is possible for this community. Regulators like the FDA signaling a willingness to overcome these challenges is a good step in the right direction, but with new leadership, we will have to wait to see how they will enact these changes.
Progress Is Underway: Early Success in Dravet Models
While its still early, promising steps are underway. Just last year, DSF funded a project exploring a type of gene editing known as base editing, in a collaboration between Dr. David Liu (MIT/Harvard), a leader in base editing technology and Dr. Ethan Goldberg (CHOP), an expert in Dravet syndrome research and care.
At the ASGCT meeting, their team presented encouraging results using cell and mouse models, showing that this gene correction approach improved neuron signaling, reduced seizures, and prevented early death. (Nelson et al., “Adenine Base Editing Rescues Dravet Syndrome in Mice,” ASGCT 2025, Poster #491)
Gene editing may still feel futuristic—but it’s getting closer to reality. As the science progresses, DSF remains committed to funding foundational academic research and providing partnership to drug-developers, ensuring that families affected by Dravet syndrome can benefit from every possible breakthrough on the horizon.
Delivering Gene Therapies to the Brain Might Be Getting Easier
Getting gene therapies into the brain is no small feat. The central nervous system (CNS)—which includes the brain and spinal cord—is protected by the blood–brain barrier, a natural defense that blocks many substances from entering. While essential for our health, this barrier makes it difficult to deliver therapies directly to the brain.
Gene therapies, which rely on delivering DNA-based instructions into cells, need special “packaging” to protect and guide them to the right place. The most commonly used delivery system for reaching the brain today is the AAV9 vector—a type of adeno-associated virus that acts as a shell to carry the genetic material. However, AAV9 does not cross the blood–brain barrier efficiently and would end up more often in tissues where it is not needed if delivered via IV, so these therapies often require more invasive administration methods, like intrathecal injection (similar to a lumbar puncture) or direct brain injection.
That may be changing.
A New Generation of Brain-Targeting Vectors
Recent advancements in vector engineering are opening the door to IV-administered gene therapies that can reach the brain without the need for surgical procedures. These next-generation vectors have shown early promise in animal models, and some are now advancing into human trials.
Several companies are leading the way:
- Capsida Therapeutics recently received FDA clearance to launch a clinical trial for an IV-delivered gene therapy for STXBP1 deficiency, a rare neurodevelopmental condition that includes epilepsy.
- Apertura Therapeutics is developing similar IV-delivered therapies for Rett syndrome and Tuberous Sclerosis Complex.
If these trials prove successful, they could reshape how gene therapies are delivered for a wide range of neurological conditions—including Dravet syndrome. It is an exciting moment, and DSF is watching these developments closely as we continue to support early research efforts that could one day bring these innovations to this community.
Changing Incentives for Rare Disease Drug Development
Rare disease drug development is costly, and when the number of patients who might benefit from a therapy is small, the potential return on investment for companies can be limited. Over the years, several programs have been introduced to encourage companies to prioritize treatments for rare diseases—helping ensure these patient communities aren’t overlooked.
The Reality Behind the Numbers
Still, only about 5% of rare diseases currently have an FDA-approved therapy, leaving a vast landscape of unmet medical need. Even though Dravet syndrome is part of that 5%, with three FDA-approved anti-seizure medications, the symptom burden of Dravet syndrome remains high. Now, with new leadership at the FDA and shifting priorities in government, some of these incentive programs are being phased out—or at the very least, significantly restructured.
Sun-setting on the Pediatric Priority Review Voucher Program
For years, Pediatric Priority Review Vouchers (PRVs) have helped encourage companies to develop treatments for rare pediatric diseases. These vouchers were awarded when a company received FDA approval for a drug treating a rare pediatric condition. In return, the company could use the PRV to speed up the review of another drug—cutting the timeline by several months—or sell the voucher to another company for millions of dollars.
This program created a strong incentive for companies to invest in rare disease treatments, where patient populations are small, trials are complex, and profits may be limited. Unfortunately, Congress did not renew the PRV program, raising serious concerns in the rare disease advocacy community.
A New Program: Commissioner’s National Priority Voucher (CNPV)
In June, the FDA announced a new initiative: the Commissioner’s National Priority Voucher (CNPV) program. This program intends to dramatically reduce FDA review times—from the standard 10–12 months down to just 1–2 months—after a company submits its final drug application.
CNPV reviews will use a “board-style” team approach and are expected to offer increased communication between the FDA and drug developers throughout the clinical trial process.
Unlike PRVs, CNPVs will not be sold or transferred between companies. They will be awarded at the discretion of the new FDA Commissioner, Dr. Marty Makary, to programs that align with key national health priorities, such as:
- Responding to U.S. health crises
- Advancing innovative treatments for Americans
- Addressing unmet public health needs
- Strengthening domestic drug manufacturing
While this approach could streamline drug development, it remains unclear how many CNPVs will be awarded or how the FDA will determine which therapies qualify. Many drug programs—including those for rare diseases—may meet these criteria. But with limited vouchers expected in the first year, there’s uncertainty about whether rare diseases will continue to be a priority for the award of these vouchers.
Why This Matters
Fast and efficient drug development pathways are essential—especially for people with rare diseases, who often wait years for effective treatments. As incentives shift, continued advocacy is critical to ensure that the needs of rare disease patients are not left behind in the process. Check out AdvocateforDravet.org to learn more ways you can advocate for rare disease issues.
The road to transformative treatments for Dravet syndrome is long—but thanks to relentless research, smart policy, and community support, it is not out of reach.
Want to learn more about therapies in development for Dravet syndrome?
- Browse actively enrolling research studies and the pipeline of therapies in development at DravetClinicalTrials.org
- Read about challenges and progress in a genetic therapy for Dravet syndrome at DravetGeneTherapy.org
