Arcturus Therapeutics (NASDAQ:ARCT) CEO Joe Payne told investors at the 38th Annual ROTH Conference that the company is refocusing on rare disease programs after gaining approvals for its COVID-19 vaccine in more than 30 countries. Payne said Arcturus had initiated a rare disease strategy for messenger RNA (mRNA) medicines before the pandemic and is now returning to that core emphasis in the post-pandemic period.
Shift back to rare diseases and platform positioning
Payne described Arcturus as an mRNA medicines company with “differentiating technologies” that support applications requiring repeat dosing, including intravenous and inhaled use. He highlighted the company’s LUNAR lipid nanoparticle delivery technology and manufacturing capabilities aimed at producing relatively pure mRNA. According to Payne, these factors differentiate Arcturus from other mRNA developers that are focusing on areas like oncology.
ARCT-810 in OTC deficiency: seeking FDA clarity for pediatrics
Payne discussed ARCT-810, an mRNA therapy being developed for ornithine transcarbamylase (OTC) deficiency, which he called the number one urea cycle disorder. He characterized the company’s approach as a “transient therapy,” contrasting it with gene editing and gene therapy efforts in the space, and argued that the liver’s regenerative nature makes it well-suited for repeat dosing with mRNA medicines.
He said Arcturus has completed multiple Phase 1 and Phase 2 trials in the U.S. and Europe and has shown the therapy to be safe and well-tolerated in adults, along with what he described as “pretty convincing biomarker changes.” However, he emphasized that investors and the market want to understand the regulatory path for use in the most severe pediatric patients, particularly children ages 0–6.
When asked what the FDA might require to support a path to approval in severe children, Payne said the company is in the middle of scheduling and conducting Type C meetings and was not prepared to provide specifics on the evidence package. He indicated the company would like to pursue a relatively small, single-arm pediatric study “sooner than later,” but said it is up to the FDA to determine what will be sufficient.
Payne said Arcturus expects to receive and process FDA feedback in the second quarter of this year, noting that the company has two Type C meetings planned—one focused on pediatrics and another on the stable adult population, where biomarker and regulatory expectations may differ.
Commercial and competitive context in OTC deficiency
Payne said the pediatric population represents the highest unmet need and “most significant commercial opportunity” within OTC deficiency, while declining to offer specific market sizing and suggesting it was too early for detailed guidance. He pointed to the historical ammonia scavenger business in urea cycle disorders and referenced Horizon as an example of a large company built around such a product.
On competition, Payne noted that Ultragenyx is approaching potential marketing authorization in stable adults with a gene therapy (which he described as a viral vector-delivered DNA medicine). He said Arcturus’ initial commercial strategy in adults would focus on non-responders to that therapy, and also on patients who may prefer a transient approach given the regenerative nature of the liver.
Payne added that Arcturus believes its therapy could be applicable broadly across genotypes and emphasized that the company’s lipids are biodegradable and non-accumulating, stating that the company has not seen significant safety concerns to date.
ARCT-032 in cystic fibrosis: extending dosing to 12 weeks
Turning to ARCT-032, Arcturus’ inhaled mRNA candidate for cystic fibrosis (CF), Payne reviewed early signals the company reported last year, including mucus plug reduction at a 10 mg daily dose over 28 days. He said the company is starting a 12-week study at the same 10 mg daily dose, expanding from earlier smaller cohorts to a trial targeting 20 subjects, mostly Class I CF patients.
Payne said the upcoming study is designed to evaluate lung function improvements in addition to mucus plug reduction, citing two commonly used endpoints in CF:
- FEV (forced expiratory volume), which he described as an older and more subjective test dependent on patient effort.
- LCI (lung clearance index), which he described as a more sensitive, passive measurement based on how long it takes the lungs to equilibrate from 100% oxygen back to normal air.
He said Arcturus is collecting both FEV and LCI as “two shots on goal,” and suggested that seeing improvement in either measure could support a path forward. Payne also explained why LCI could be well-suited for an inhaled, topically delivered therapy, describing the treatment effect as potentially incremental—“peeling away a diseased onion” over time—rather than systemic. He said the company views ARCT-032 as potentially “duration responsive” and is extending treatment duration to test whether longer exposure can drive meaningful lung function improvement, while keeping dose flexibility (including a 15 mg option) as a future consideration.
Capital runway and funding strategy
On financing, Payne said the company has not raised capital for several years and noted a stated cash runway into the second quarter of 2028, excluding milestones. He said Arcturus has historically monetized its platform through business development, including smaller deals and a larger vaccine partnership with CSL, and may pursue additional non-dilutive funding opportunities. Payne added that while the current runway supports significant value creation across the two lead programs, the company does not have sufficient capital to take both programs through completion and Phase 3 trials without a strategic funding plan, though he said it was too early to provide timing guidance.
About Arcturus Therapeutics (NASDAQ:ARCT)
Arcturus Therapeutics Holdings Inc is a clinical-stage biotechnology company dedicated to developing messenger RNA (mRNA) medicines that address a range of diseases. The company leverages its proprietary STARR® mRNA platform to enable precise control over mRNA expression, supported by its lipid nanoparticle delivery technology, LUNAR®. Arcturus’s approach is designed to address both therapeutic and prophylactic applications, with an emphasis on vaccines and treatments for rare genetic and infectious diseases.
The company’s pipeline includes ARCT-810, an mRNA therapeutic candidate for phenylketonuria (PKU), and ARCT-021 (also known as LUNAR-COV19), a COVID-19 vaccine candidate developed in collaboration with Duke-NUS Medical School in Singapore.
