aibioArcturus files $500,000,000 replacement shelf with $187,765,319 ATM prospectus
Tickers ARCT
The at-the-market sales agreement names Cantor Fitzgerald, Wells Fargo Securities and William Blair. As of December 22, 2025, the company had sold 1,179,201 shares under it for about $12 million.
Key facts
- Company
- Arcturus Therapeutics Holdings Inc. (NASDAQ: ARCT)
- News type
- Financings
- Primary source
- Arcturus Therapeutics Holdings Inc. S-3 (2025-12-30)
The new shelf
Arcturus Therapeutics Holdings Inc. filed a Form S-3 shelf registration statement with the Securities and Exchange Commission on December 30, 2025. The filing replaces an earlier S-3 (File No. 333-269003) that was first filed on December 23, 2022 and declared effective on December 30, 2022. Under Rule 415(a)(6), the company carries $487,765,319 of unsold securities from that earlier registration into the new one, along with the $53,752 registration fee paid on them.
The filing contains two prospectuses. The base prospectus covers up to $500,000,000 of common stock, preferred stock, debt securities, warrants and units. The second, an at-the-market prospectus, covers up to $187,765,319 of common stock sold through a Controlled Equity Offering sales agreement with Cantor Fitzgerald & Co., Wells Fargo Securities, LLC and William Blair & Company, L.L.C., as sales agents. The at-the-market amount is stated in dollars only, with no share count.
The company says it may keep selling common stock under the earlier registration, through the same three agents, until the new one takes effect or until June 28, 2026, whichever comes first. The filing describes that date as 180 days after the third anniversary of the earlier registration's effective date. The earlier at-the-market offerings are covered by a prospectus supplement filed on December 23, 2022 and another filed on August 7, 2023.
The at-the-market program so far
The original sales agreement was covered by a prospectus supplement filed on December 23, 2022 for up to $200 million of common stock. As of December 22, 2025, the company said it had sold an aggregate of 1,179,201 shares under that agreement, for aggregate gross proceeds of approximately $12 million. It said about $188 million of shares remained available for sale under the agreement.
The filing sets out what the agents receive. The sales agents are paid 3% of the gross proceeds of any shares sold under the agreement. The agents are deemed to be underwriters under the Securities Act, and their compensation is treated as underwriting commissions or discounts. The company has agreed to provide indemnification and contribution to the agents. The agents are not required to sell any specific amount, and the filing says there is no arrangement for funds to be received in escrow.
The filing does not explain why sales under the first program have reached roughly $12 million against a $200 million facility. It does not say how the sales were split among the three agents, or at what prices the shares were sold.
Uses of money and what the filing leaves open
The base prospectus says the company would use net proceeds from securities sold under it for sales and marketing, working capital and general corporate purposes, unless a supplement says otherwise. It adds that the company may use part of the proceeds for acquisitions or in-licenses of, or investments in, complementary businesses, medicines or technologies. It has no agreements or commitments for any specific transaction.
Among the uncertainties the filing lists is the company's ability to obtain and deploy funding for its operations, and its ability to continue as a going concern. The filing does not give the company's cash balance, revenue or net loss. The prospectus instead incorporates other filings by reference, so those figures have to be checked in the documents it names.
The business behind the program
According to the business section of its annual report for 2024, filed March 6, 2025, Arcturus is a messenger RNA medicines company focused on infectious disease vaccines and on opportunities within liver and respiratory rare diseases. Its product KOSTAIVE, a self-amplifying mRNA vaccine against COVID-19, was approved in Japan in 2023. Sales began there in October 2024, which the company describes as its transition to a commercial stage company.
The company says its STARR self-amplifying platform has been demonstrated to induce a longer-lasting and broader immune response at lower dose levels than conventional mRNA-based vaccines. That is the company's own claim, and the business section does not include the study data behind it. The company says its internal pipeline includes RNA therapeutic candidates to potentially treat ornithine transcarbamylase (OTC) deficiency and cystic fibrosis (CF).