[8-K] Arcturus Therapeutics Holdings Inc. Reports Material Event

Rhea-AI Filing Summary

Arcturus Therapeutics Holdings Inc. (Nasdaq: ARCT) has furnished an 8-K under Item 7.01 to disclose positive interim Phase 2 results for its mRNA candidate ARCT-810, which is being developed to treat ornithine transcarbamylase (OTC) deficiency. The company states that the investigational therapy is designed to replace the OTC enzyme and restore urea-cycle function, thereby preventing hyperammonemia crises in affected patients.

• A press release detailing the data and a webcast presentation were released on 30 Jun 2025 and are attached as Exhibits 99.1 and 99.2.
• The disclosure is furnished—not filed—under Regulation FD; therefore, it carries no Section 18 liability and will not be incorporated by reference into future SEC filings.
• No financial statements, earnings figures, or transaction details are included.

The filing underscores continued progress in Arcturus’s rare-disease pipeline and may influence investor sentiment pending full Phase 2 data and eventual pivotal trials.

Positive

• Positive interim Phase 2 results for ARCT-810 suggest clinical progress in addressing OTC deficiency.
• Pipeline validation of Arcturus’s mRNA platform may enhance strategic value and attract investor interest.

Negative

• None.

Insights

Biotech Equity Analyst

TL;DR: Positive Phase 2 interim data strengthens ARCT-810 pipeline value; limited financial detail.

Interim efficacy in OTC deficiency is a material milestone because it validates Arcturus’s LUNAR mRNA platform beyond vaccines. Although numerical outcomes are not disclosed here, management’s decision to issue a dedicated press release implies clinically meaningful signals. Successful advancement of ARCT-810 would open a high-value rare-disease market with limited competition, potentially de-risking the program before Phase 3. However, investors will need quantitative safety and efficacy data to gauge commercial potential.

Risk Analyst

TL;DR: Disclosure is informational; regulatory and data-readout risks remain.

The 8-K is furnished, not filed, limiting legal exposure—a routine practice for preliminary clinical updates. While interim results are described as positive, absence of detailed metrics means efficacy durability, safety profile, and regulatory path remain uncertain. Future capital needs for late-stage trials could dilute shareholders. Still, today’s news is incrementally favorable for sentiment and partnering optionality.

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UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d)

of the Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): June 30, 2025

ARCTURUS THERAPEUTICS HOLDINGS INC.

(Exact name of registrant as specified in its charter)

Delaware		001-38942		32-0595345
(State or other jurisdiction of incorporation)		(Commission File Number)		(I.R.S. Employer Identification No.)

10628 Science Center Drive, Suite 250

San Diego, California 92121 

(Address of principal executive offices)

Registrant’s telephone number, including area code: (858) 900-2660

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

☐	Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)
☐	Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)
☐	Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))
☐	Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act:

Title of each class		Trading Symbol(s)		Name of each exchange on which registered
Common stock, par value $0.001 per share		ARCT		The Nasdaq Stock Market LLC

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).

Emerging growth company ☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Item 7.01. Regulation FD Disclosure.

On June 30, 2025, Arcturus Therapeutics Holdings Inc. (the “Company” or “Arcturus”) issued a press release, announcing positive Phase 2 interim results in people with OTC deficiency treated with ARCT-810, an mRNA therapeutic candidate designed to replace the OTC enzyme and restore urea cycle activity preventing hyperammonemia crises (the “Release”). The Company also provided a corporate presentation regarding ARCT-810 via webcast, which is available on the Company’s website (the “Presentation”).

A copy of the Release is furnished herewith as Exhibit 99.1 and incorporated into this Item 7.01 by reference. A copy of the Presentation is furnished herewith as Exhibit 99.2 and incorporated into this Item 7.01 by reference.

The information in this Item 7.01 of this Current Report on Form 8-K, and Exhibit 99.1 and 99.2 attached hereto, 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, the Release attached as Exhibit 99.1, and in the Presentation attached as Exhibit 99.2 to this Current Report on Form 8-K, 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.   

Item 9.01 Financial Statements and Exhibits.

(d) Exhibits.

Exhibit No.	Description of Exhibit
99.1	Press Release dated June 30, 2025
99.2	Presentation dated June 30, 2025
104	Cover Page to this Current Report on Form 8-K in Inline XBRL

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

	Arcturus Therapeutics Holdings Inc.
Date: June 30, 2025
	By:	/s/ Joseph E. Payne
	Name:	Joseph E. Payne
	Title:	Chief Executive Officer

FAQ

What did Arcturus Therapeutics (ARCT) announce on June 30, 2025?

Arcturus issued an 8-K reporting positive Phase 2 interim results for its mRNA therapy ARCT-810 targeting OTC deficiency.

What is ARCT-810?

ARCT-810 is an mRNA therapeutic candidate designed to replace the OTC enzyme and restore urea-cycle activity in OTC deficiency patients.

Where can investors find the detailed Phase 2 interim data?

The company’s press release (Exhibit 99.1) and webcast presentation (Exhibit 99.2) are available on Arcturus’s website.

Is the information in this 8-K considered filed with the SEC?

No. The disclosure is furnished under Regulation FD and is not deemed "filed" for Section 18 purposes.

Does the 8-K include any financial or earnings data?

No financial statements, earnings metrics, or transaction details are included in this filing.