Current Report · Items 7.01, 9.01 · 8-K

Arcturus Therapeutics Holdings Inc.

ARCTNASDAQEQUITYCurrent

Regulation FD Disclosure

Filed Sep 23, 2026Accepted Sep 23, 2026, 4:11 PM EDTCIK 1768224Accession 0001193805-26-001277

Company context

Founded in 2013 and based in San Diego, California, Arcturus Therapeutics Holdings Inc. (Nasdaq: ARCT) is a messenger RNA medicines company focused on the development of liver and respiratory therapeutics with enabling technologies: (i) LUNAR® lipid-mediated delivery, (ii) STARR® mRNA technology (sa-mRNA) and (iii) mRNA drug substance along with drug product manufacturing expertise. Arcturus developed KOSTAIVE®, the first self-amplifying messenger RNA (sa-mRNA) COVID vaccine in the world to be approved. Arcturus’ strategic collaborations include Thermo Fisher Scientific for ARCT-032 manufacturing and development, BARDA for pandemic influenza initiatives, and ARCALIS, a Japanese joint venture focused on manufacturing mRNA vaccines and therapeutics. Arcturus’ pipeline includes programs in cystic fibrosis (CF), ornithine transcarbamylase (OTC) deficiency, phenylketonuria (PKU) and Gout. Arcturus’ versatile RNA therapeutics platforms can be applied toward multiple types of nucleic acid medicines including messenger RNA, small interfering RNA (siRNA), circular RNA, antisense RNA, self-amplifying RNA, DNA, and gene editing therapeutics. Arcturus’ technologies are covered by its extensive patent portfolio (over 500 patents and patent applications in the U.S., Europe, Japan, China, and other countries). For more information, visit www. ArcturusRx.com. Please connect with us on X and LinkedIn.

Current securities

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Recent company filings

Disclosure sections

Items 7.01, 9.01

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Item 7.01Item 7.01 - Regulation FD Disclosure

Item 7.01. Regulation FD Disclosure. On September 23, 2026, Arcturus Therapeutics Holdings Inc., a Delaware corporation (the “Company” or “Arcturus”) presented an overview of ARCT-810 Phase 2 clinical data, provided an update on its mRNA delivery platform (the “Presentation”) and issued a press release which summarizes the Presentation (the “Release”). Copies of the Presentation and Release are furnished herewith as Exhibit 99.1 and Exhibit 99.2, respectively, and are incorporated into this Item 7.01 by reference. The information in this Item 7.01 of this Current Report on Form 8-K, the Presentation and the Release, shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended, or otherwise subject to the liabilities of that section or Sections 11 and 12(a)(2) of the Securities Act of 1933, as amended. The information contained in this Item 7.01, and in the Presentation and the Release, shall not be incorporated by reference into any filing with the Securities and Exchange Commission made by the Company, whether made before or after the date hereof, regardless of any general incorporation language in such filing.

Filed exhibits (1)

EX-99.2 (by filename) e665798_ex99-2.htm

Arcturus Therapeutics Announces Interim OTC Deficiency Phase 2 Results and Introduces LUNAR 2.0™ Next-Generation mRNA Delivery Platform ARCT-810 generally safe and well tolerated, demonstrating encouraging activity across key urea cycle biomarkers in ongoing Phase 2 study LUNAR 2.0™ produces greater than 30-fold higher protein expression in multiple NHP studies - unlocks new therapeutic opportunities ARCT-2601, an OTC deficiency therapeutic candidate utilizing LUNAR 2.0™, to be integrated by YE 2026 into ongoing Phase 2 study as advised by the FDA Arcturus to acquire myNEO, an AI discovery company, to improve mRNA design quality, accelerate innovation, and enhance target identification capability Presentation at 4:30 p.m. ET today SAN DIEGO--(BUSINESS WIRE)--September 23, 2026--Arcturus Therapeutics Holdings Inc. (the “Company,” “Arcturus,” Nasdaq: ARCT), a messenger RNA medicines company focused on the development of liver and respiratory therapeutics, today announced encouraging interim Phase 2 results from ARCT-810 in ornithine transcarbamylase (OTC) deficiency and introduced LUNAR 2.0™, the Company’s next-generation mRNA delivery platform, and additional liver pipeline pr…

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