The FDA’s National Priority Voucher (NPV) program is reshaping how critical therapies reach patients, compressing review timelines from the typical 10–12 months to as little as one to two months. While the program’s second batch of products prominently featured cancer therapies and GLP-1 metabolic drugs, it also included two treatments rooted in global and tropical public health: Johnson & Johnson’s Sirturo for multidrug-resistant tuberculosis (MDR-TB) and Vertex/CRISPR Therapeutics’ Casgevy gene therapy for sickle cell disease (SCD).
Both therapies carry significant promise but also raise important public health questions. Casgevy represents a cutting-edge genetic intervention with transformative potential for patients with few options, while Sirturo tackles a persistent global infectious threat. In both cases, the voucher appears to be supporting efforts to expand use in pediatric populations.
From a regulatory science perspective, this is a calculated move. The FDA is cherry picking operational safe bets to stress test its new speed limits.
- Johnathon Anderson, UC Davis School of Medicine, Peptide Systems.
Carl Schoellhammer, a Biopharma Strategy Consultant at DeciBio, told DDN that both Sirturo and Casgevy are reasonable products to include. “These are two products that could address significant unmet needs. Casgevy, for example, could dramatically reduce complications from sickle cell disease, avoiding emergency visits and improving quality of life. I suspect these were selected to understand how the program functions in practice and to address friction points in prescribing and adoption.”
Johnathon Anderson, Associate Professor and Program Officer at the University of California, Davis School of Medicine and the CEO of Peptide Systems, also told DDN that he views the selections as a strategic “beta test” by the agency. “Both awards are for supplemental New Drug Applications rather than unproven molecules,” he said. “From a regulatory science perspective, this is a calculated move. The FDA is cherry picking operational safe bets to stress-test its new speed limits.”
He stressed that it’s far easier to move quickly on a label expansion for a known drug than on a brand-new molecule. This lets the FDA test faster reviews without taking on major biological risk.
Still in its early stages, the NPV program appears to be as much a test of the FDA’s own operational limits as it is a new regulatory pathway. Will this scheme improve access to unmet public health needs, or will it reduce incentives for innovation and risk public health?
Johnson & Johnson’s Sirturo
In 2012, Sirturo (bedaquiline) became the first new TB treatment in 40 years to gain FDA approval, receiving accelerated clearance for eligible adult patients based on positive Phase 2 data. In 2019, the FDA approved 100mg tablets for use in adolescents (ages 12–17, weighing at least 30kg) with MDR-TB when no effective alternative regimen is available. The following year, a pediatric formulation was approved for children aged five and older and weighing at least 15kg.
Today, Sirturo is a cornerstone of World Health Organization (WHO)-recommended regimens for drug-resistant TB, with roughly three-quarters of MDR-TB patients on treatment receiving an all-oral bedaquiline-containing regimen. The drug targets mycobacterial ATP (adenosine triphosphate) synthase, killing even non-replicating bacteria.
Clinical studies, including systematic reviews of trials and cohort analyses, have shown that bedaquiline-containing regimens are associated with higher treatment success rates, faster culture conversion, and reduced mortality than regimens without it. However, Sirturo carries a known risk of cardiac side effects, including potentially serious heart rhythm disturbances.
The voucher is being used to support the review of pediatric data from a Phase 2 study assessing the safety, pharmacokinetics, and anti‑TB activity of bedaquiline in children from infancy through adolescence — including dose selection for younger age cohorts — with the aim of expanding approved use in pediatric MDR‑TB patients.
Commenting on the announcement, a Johnson & Johnson representative told DDN, “We were pleased to learn of the selection of Sirturo for the treatment of MDR-TB in children aged zero to two years for expedited review under the FDA’s Commissioner’s National Priority Voucher program. We welcome opportunities such as this to help enable more patients to access the medicines they need.”
While Johnson & Johnson frames the voucher as a pathway to faster patient access, others see the Sirturo decision as a window into how the FDA is testing the mechanics of accelerated review itself. “The balance is moving from pre-market clinical volume to predictive modelling, backed by post-market surveillance. For bench scientists, this emphasizes that a robust pharmacokinetics/pharmacodynamics model is no longer just supportive data. It is now a primary regulatory vehicle for speed,” said Anderson.
Another aspect to consider is the increasing resistance to Sirturo that has been reported in South Africa, Mozambique, Eswatini, and parts of China, as well as other low- and middle-income countries where TB prevalence is high. This is likely to become worse as funding is dramatically reduced due to the US withdrawing from the WHO and closing the US Agency for International Development. The WHO said it has already received early reports of severe disruptions in the TB response across several of the highest-burden countries following the funding cuts.
This comes at a time when TB has again become the world’s leading infectious killer, surpassing COVID-19. Despite being preventable and curable, TB still causes 1.25 million deaths each year, with 10 million people newly infected. Ongoing challenges and emerging resistance suggest that other novel TB treatments may have warranted higher priority.
Vertex/CRISPR Therapeutics’ Casgevy gene therapy
Another voucher went to Casgevy (exagamglogene autotemcel), the first CRISPR-based therapy approved for SCD and transfusion-dependent beta thalassemia (TDT). Casgevy is already authorized in the US, EU, UK, Middle East, and other regions for patients 12 and older.
Casgevy is a non-viral, ex vivo CRISPR/Cas9-edited cell therapy in which a patient’s hematopoietic stem and progenitor cells are genetically modified to produce high levels of fetal hemoglobin (HbF). HbF facilitates oxygen delivery, preventing sickling in SCD and compensating for defective hemoglobin in TDT.
Schoellhammer noted, “The interesting piece is that Casgevy is already approved. The voucher supports supplemental applications, like expanding to younger populations. From a policy perspective, this signals a focus on health priorities and access, while also potentially increasing support and reimbursement for these therapies."
New pediatric data presented at American Society of Hematology in December 2025 showed that Casgevy is now delivering strong results in children aged five to 11. In SCD, all four children with sufficient follow-up remained free of vaso-occlusive crises — the most common complication of the disease — for at least 12 months, with some now crisis-free for up to two years. In TDT, all evaluable children achieved at least one year of transfusion independence, and 12 of 13 treated have remained transfusion-free to date.
The trial reported one treatment-related pediatric death linked to busulfan, the chemotherapy used for conditioning prior to Casgevy infusion. The event was not attributed to the CRISPR editing itself but reflects the known risks of myeloablative conditioning. Overall, the safety profile in children mirrors what has been observed in older patients, who continue to show durable benefits lasting three years or more.
“These results — the first clinical data ever presented on any genetic therapy for children ages 5-11 years with SCD — again demonstrate the transformative potential of Casgevy,” said Carmen Bozic, Chief Medical Officer at Vertex, in the press release. “With dosing completed in the 5-11 age group and the Commissioner’s National Priority Voucher for Casgevy in this population in hand, we are excited to begin global regulatory filings in the first half of next year and bring this potentially transformative therapy to eligible children as soon as possible.”
From a regulatory perspective, Anderson noted that the voucher reflects a strong vote of confidence in the safety of CRISPR platforms. “Awarding a 30-day voucher for a pediatric gene therapy signals that the FDA is comfortable relying on Platform Safety Assays,” he said. “Historically, the concern with CRISPR in pediatrics has been the long-term impact of off-target edits. By expediting this review, the Agency is signaling that in silico off-target analysis and in vitro toxicity assays can serve as surrogates for clinical observation. For research and development leaders, this means the 'black box' fear of gene editing is receding, and the platform itself is becoming a 'known quantity.'”
Schoellhammer added, "The baby KJ story is a great example. With a platform designation, the FDA can reuse tools from previous approvals — delivery vehicles, transfection methods — so you don’t need to reinvent everything. That provides a scientific rationale to believe the therapy can be administered safely, even in children."
As the NPV program continues, how these pilot cases influence regulatory strategy, patient access, and innovation incentives will be closely watched by the industry.
