Arcturus Therapeutics (NASDAQ:ARCT) expects to complete enrollment in a mid-stage cystic fibrosis study by the end of 2026 and begin dosing a next-generation treatment for a rare liver disorder in the first quarter of 2027, executives said on the company’s third-quarter earnings call.
The company reported a narrower quarterly net loss of $7.4 million, compared with $13.4 million a year earlier, and said it had enough cash to fund operations through year-end 2028. Management also outlined plans for its vaccine business after regaining control of KOSTAIVE rights from CSL Seqirus.
Cystic Fibrosis Data and Phase III Decision Ahead
Arcturus expects to present full data from the fourth cohort of its Phase II study of ARCT-032 in the second quarter of 2027. The cohort is evaluating a 10-milligram inhaled dose administered daily for 12 weeks in up to 20 adults with cystic fibrosis, primarily patients with class I disease.
President and CEO Joe Payne said enrollment had accelerated after additional sites opened in Israel and Turkey. The company has not disclosed how many patients have enrolled, but expects to finish enrollment by year-end.
Payne said a decision on whether to advance ARCT-032 into Phase III is expected when top-line data become available, before the full data presentation. He did not provide a specific date for the decision or the top-line results, adding that data from patients enrolling in Israel and Turkey may be included in the decision.
A decision to move into Phase III would trigger significant contributions from collaboration partner Thermo Fisher Scientific, Payne said. Arcturus retains control over that decision.
Chief Medical Officer Alan Cohen said some patients have completed the full 12-week regimen. The company has not seen severe safety events that would trigger restrictions, a study halt or discontinuation, he said. Cohen added that access to open-label data is primarily limited to medical personnel for safety monitoring rather than efficacy assessment.
Cohen said Arcturus would likely discuss the full dataset with the Food and Drug Administration in the second half of 2027 if results support moving forward. Starting a Phase III study by the end of that year would be a “push,” he said, although the company would pursue that timing if feasible.
Next-Generation Liver Treatment Targets 2027 Readout
Arcturus plans to begin Phase II dosing of ARCT-2601 in the first quarter of 2027 and report top-line results in the second half of the year. The treatment targets ornithine transcarbamylase, or OTC, deficiency, and is the company’s first candidate using its LUNAR 2.0 delivery technology.
Payne said the company is preparing to file an investigational new drug application after incorporating final toxicology studies. The amended protocol is expected to evaluate patients ages 12 and older. Cohen said the company plans to enroll up to six subjects and use the results alongside data from the earlier ARCT-810 program in an end-of-Phase II meeting with the FDA.
In September, Arcturus presented Phase II data showing that ARCT-810 reduced or maintained first-morning fasting ammonia within the normal range at two dose levels, including during increased protein intake, and reduced glutamine levels in all participants. The treatment was generally safe and well tolerated, Payne said.
In non-human primate testing, the LUNAR 2.0 formulation showed a 38-fold improvement in potency over the original formulation used in ARCT-810, according to Payne. He said the upcoming study will provide the first opportunity to assess how that finding translates to patients.
Arcturus is also developing a LUNAR 2.0-based treatment for phenylketonuria, or PKU, and plans to submit an investigational new drug application in the second half of 2027.
Quarterly Loss Narrows as Research Spending Falls
Third-quarter revenue rose to $18.3 million from $17.2 million a year earlier, driven primarily by recognition of a $12 million termination payment and remaining deferred revenue following the end of the CSL Seqirus collaboration, Chief Financial Officer Dennis Mulroy said. Lower grant revenue partly offset the increase.
Research and development expenses fell to $17 million from $23.3 million, mainly because of reduced clinical and manufacturing activity and lower personnel and facility costs. General and administrative expenses were $10.5 million, compared with $10.4 million a year earlier. The quarterly net loss was 26 cents per share, versus 49 cents per share in the prior-year period.
For the first nine months of 2026, revenue declined to $23.3 million from $74.8 million, while the net loss widened to $58.2 million from $36.7 million. Cash and cash equivalents totaled $184.8 million at Sept. 30, down from $230.9 million at the end of 2025.
Vaccine Rights and AI Capabilities
Payne said KOSTAIVE, the company’s self-amplifying mRNA COVID-19 vaccine, continues to be commercialized in Japan through partner Meiji for the 2026-2027 season. Arcturus also completed the transfer of marketing authorization holder rights in the European Union and U.K. from CSL Seqirus, enabling it to explore commercial activities there in 2027.
For the United States, Payne said Arcturus remains consistent in its plan to seek a partner. The company also completed its acquisition of myNEO, adding artificial intelligence capabilities in antigen design, mRNA optimization and target identification. Payne said Arcturus remains focused on its therapeutics pipeline but is open to supporting companies in oncology.
About Arcturus Therapeutics (NASDAQ:ARCT)
Arcturus Therapeutics Holdings Inc is a biotechnology company headquartered in San Diego, California, focused on developing medicines based on messenger RNA (mRNA) and other RNA technologies. The company’s platform includes LUNAR, a lipid-mediated delivery system designed to transport nucleic acids into cells, as well as technologies for producing and administering mRNA and self-amplifying RNA.
The company’s development programs address infectious diseases and rare genetic disorders. Arcturus has developed KOSTAIVE, a self-amplifying mRNA COVID-19 vaccine known as ARCT-154, in collaboration with CSL.
