Joseph E. Payne
Two weeks ago, I, along with our team, had the privilege of attending the North American Cystic Fibrosis Conference in Seattle. It was great to meet with the CF Foundation leadership team and share our enthusiasm for the class one population based on our encouraging data. I met with the physicians and principal investigators involved in our ongoing clinical trials and was very pleased to hear their anecdotes, positivity, and encouragement. I enjoyed meeting with multiple CT scan experts and felt their passion as they described the present and future importance of HRCT imaging data in lung disease trials. I affirmed my appreciation of the significant unmet medical need represented by class one CF and other CFTR modulator nonresponders here in the United States. There is an even higher prevalence of people with class one CF in countries outside the US, especially in Europe, India, the Middle East, and Israel. All in all, the conversations with the CF Foundation, people with class one CF, their physicians, investigators, CT scan experts, and global CF representatives reinforced Arcturus' commitment to advance ARCT032 further into development. The safety and tolerability profile data, along with the before and after treatment HRCT scan images showing mucus plug reduction, were well received by the CF community. We look forward to collecting additional and potentially meaningful clinical data in 2026 for our CF program. Moving on to the ARCT810 program, this is our messenger RNA therapeutic candidate for ornithine transcarbamylase deficiency, or OTC deficiency. With positive interim phase two data in hand, the company is diligently preparing for meetings with regulatory agencies in 2026 to discuss pivotal trial strategy for both pediatric and adult populations. Understanding what the FDA requires for ARCT810's path to approval is the next key milestone for this program. We aim to provide more details pertaining to these regulatory alignment meetings in 2026. I will now provide regulatory updates for our partnered COVID-19 vaccine program, also known as Costave. Our Japanese partner, Meiji Seika Pharma, has launched the two-dose vial of Costave updated for the JN1 variant XE in Japan. This is the first time the two-dose vial presentation is being distributed in Japan. Meiji received approval from the Pharmaceuticals and Medical Devices Agency, or PMDA, in August. Also in August, the company published the phase three manuscript on the immunogenicity and safety of our self-amplifying mRNA COVID-19 vaccine ARCT2303. The study shows that ARCT2303 induces a robust immune response against SARS-CoV-2 and can be co-administered with licensed influenza in adults with no impact on safety or immunogenicity of either vaccine. The results were published in eClinical Medicine. Moving on to ARCT2304, this is our next-gen STAR vaccine candidate for pandemic A/H5N1 influenza virus. This is the program contracted with and funded in part by BARDA. We conducted a Phase I study in 132 young adults and 80 older adults. ARCT2304 induced a humoral immune response after a single dose in all tested dose levels. The administration of a second dose of ARCT2304 further increased immune responses. ARCT2304 at dose levels of 1.5, 5, and 12 micrograms induced a hemagglutinin-specific immune response similar to or higher than the MF59 adjuvanted pandemic vaccine in both young and older adults. No safety or tolerability concerns were raised from available data. These data further validate our STAR SA mRNA platform. The study results support the further development of the self-amplifying mRNA pandemic influenza vaccine candidate. With that, I'll now pass the call to Andy.