Arcturus Therapeutics Holdings Inc.

Today's call is being recorded. I would now like to turn the call over to Neda Sofarzadeh, Vice President, Head of Investor Relations, Public Relations, and Marketing. Please go ahead.

Thank you, Operator. Good afternoon and welcome to ArcTera Therapeutics quarterly financial update and pipeline progress call. Today's call will be led by Joe Payne, our President and CEO, and Andy Sassine, our CFO. Dr. Pat Srivukula, our CSO and COO, will join them for the Q&A session. Before we begin, I would like to remind everyone that the statements made during this call regarding matters that are not historical facts are forward-looking statements within the safe harbor provisions of the Private Securities Litigation Reform Act of 1995. Forward-looking statements are not guarantees of performance. They involve known and unknown risks, uncertainties, and assumptions that may cause actual results, performance, and achievements to differ materially from those expressed or implied by the statement. Please see the forward-looking statement disclaimer on the company's press release issued earlier today, as well as the risk factor section in our most recent form, 10-K, and in subsequent filings with the SEC. In addition, any forward-looking statements represents our views only as of the date such statements are made. Arcturus specifically disclaims any obligation to update such statements. And with that, I will now turn the call over to Joe.

Thank you, Netta. It's good to be with you again, everybody. Over the last few months, there has been elevated interest in our mRNA therapeutics pipeline, given that we have meaningful clinical data sets forthcoming. So I will begin today's call with updates pertaining to our mRNA therapeutics pipeline. I will begin with an update on ARCT032. This is our messenger RNA therapeutic candidate for cystic fibrosis. Arcturus is advancing enrollment in the open label phase two, multiple ascending dose CF study in adults with CF who are not eligible for CFTR modulator therapy or are not taking CFTR modulators due to drug intolerance, poor response, or lack of access to modulators. Each adult participant in the Phase 2 CF study is expected to receive daily inhaled treatments of ARCTO32 or over a period of 28 days. The study began last December and to date, The study continues in multiple subjects without safety or tolerability issues. The company expects to complete phase two enrollment by the end of the year and provide phase two interim data for the first two cohorts in mid 2025. I'll now move on to our ARCT 810 program. This is our messenger RNA therapeutic candidate for ornithine transcarbamylase or OTC deficiency. Arcturus continues to enroll participants in the open-label Phase II OTC deficiency study with five intravenous infusions of ARCT810 over a period of two months. The company previously completed the dosing phase involving a cohort of eight people, and the dosing was at 0.3 mg per kg of a placebo-controlled European study enrolling OTC-deficient individuals. the company expects to provide Phase II interim data this quarter, or Q2 2025. The U.S. Phase II study evaluates several biomarkers, including glutamine and ammonia. Elevated glutamine levels can occur when ammonia scavengers are used, particularly in individuals with urea cycle disorders, such as OTC deficiency. While ammonia scavengers reduce circulating ammonia, glutamine may still be elevated due to its role as a temporary ammonia repository and therefore may be used as a useful biomarker to ascertain proper urea cycle function in OTC deficient individuals. We are also utilizing a newly developed and improved 15N ureogenesis assay. This is supported by a newly published paper out of Haberle's lab at the University of Zurich. This 15N ureogenesis assay is expected to provide important data for monitoring the effect of ARCTA10 in the company's clinical development program. We are encouraged by the comprehensive data we have collected to date with our CF and OTC programs. And given the current market conditions, we have made a strategic decision to focus our resources toward our mRNA therapeutics pipeline. I now shift your attention to our partnered COVID-19 vaccine program. We are pleased about the recent EU approval of CoStave. This is our self-amplifying mRNA COVID-19 vaccine. Arcturus received an initial milestone payment from CSL, our global vaccine partner, in relation to the EU approval of COSTAVE. We continue to make progress expanding the global COSTAVE franchise. The company anticipates a Marketing Authorization Application, or MAA, filing in the United Kingdom in Q2 2025, followed by a USBLA filing in Q3 2025. The WHO is expected to announce the updated COVID strain later this week, and we, along with our partner, CSL Securus, will update CoStave accordingly to support Meiji's distribution efforts in Japan this upcoming season. Our STAR self-amplifying mRNA platform continues to benefit from meaningful publications. The company recently published a comprehensive analysis of safety data for CoStave, with a 12-month follow-up from the pivotal clinical study in Vietnam, which had over 17,000 participants who received at least one dose of the study vaccine. The study confirmed the favorable reactogenicity profile. Acceptable tolerability of ARCT154 was also observed in older participants and individuals at high risk of severe COVID-19 due to underlying medical conditions. Long-term data from this large trial suggests that the SA mRNA COVID vaccine is safe and well-tolerated and did not include any reports of myocarditis or pericarditis. In April, Arcturus' Japanese partner, Meiji Seika Pharma, published an analysis characterizing the distribution and clearance of ARCT154-encoded spike protein and non-structural proteins in the lymph nodes and injection site muscle in mice following a single intramuscular vaccination. The study showed the encoded spike protein reached its highest level approximately three days after vaccination and quickly disappeared from the injection site muscle. The spike protein persisted up to 28 days in lymph nodes after vaccination, and the data suggests that this prolonged spike protein expression may be credited for the observed higher immunogenicity. And as expected, the study also confirmed that the replication is limited. Now moving to ARCT 2304. This is our SA mRNA vaccine candidate for pandemic influenza A, which is also known as H5N1 or the bird flu virus. In April, Arcturus received US FDA fast track designation for ARCT 2304. As a reminder, this project has been supported in whole with federal funds from the HHS, ASPR, and BARDA. The company recently completed the recruitment of 212 adults, which included 80 participants over the age of 60 years old, in a randomized placebo-controlled phase 1 trial being conducted here in the U.S. The company expects interim phase one data in the second half of 2025. And with that, I will now pass the call to Andy.