Key Highlights

● Arcturus revenue fell to $3.0 million as the CSL Seqirus collaboration ended.

● Cash was $191.5 million at June 30, with runway management puts through 2028.

● A decision on advancing ARCT-032 to Phase 3 is due in the fourth quarter.

● CSL Seqirus will pay $12 million, and Arcturus regained global vaccine rights.

Arcturus Therapeutics (NASDAQ:ARCT) is betting on its cystic fibrosis program, ARCT-032, because the exit of CSL Seqirus from its vaccine collaboration has removed a key revenue source and returned global rights to its infectious-disease portfolio. The company says a decision on whether to proceed to Phase 3 is due in the fourth quarter of 2026.

Second-quarter results

Arcturus, a Nasdaq-listed messenger RNA medicines company, reported second-quarter 2026 results on August 6, 2026. Revenue was $3.0 million, against $28.3 million in the second quarter of 2025. For six months, revenue was $5.0 million, compared with $57.7 million. The company attributes the drop to lower collaboration revenue from CSL Seqirus after the agreement ended.

The GAAP net loss for the quarter was $23.8 million, or $0.84 per share, compared with a loss of $9.2 million, or $0.34, a year earlier. For six months the loss was $50.7 million, or $1.79 per share. Cash and cash equivalents were $191.5 million at June 30, 2026, down $39.4 million from $230.9 million at the end of 2025.

Cash runway

The chief financial officer said the company has a cash runway of more than two and a half years, through the end of 2028. That is a management statement and depends on spending plans and on the outcome of the clinical programs.

The CSL Seqirus settlement

The collaboration with CSL Seqirus was ended through a settlement. Arcturus regained global rights to KOSTAIVE, its self-amplifying mRNA COVID-19 vaccine, and to its wider infectious-disease vaccine portfolio. Existing arrangements with Meiji Seika Pharma for Japan's 2026 and 2027 season remain. CSL Seqirus will pay $12 million in cash, and about $16 million of research-credit liabilities were released. A European milestone arbitration was also resolved.

The settlement simplifies ownership of the vaccine assets but sharply reduces near-term revenue, so the company is now more dependent on its cash balance and its therapeutic pipeline.

ARCT-032 in cystic fibrosis

ARCT-032 is an inhaled mRNA candidate for cystic fibrosis. An open-label Phase 2 study is enrolling patients in the United States, Israel and Turkey. Cohort 4 is testing a daily 10 mg inhaled dose over 12 weeks. Thermo Fisher (NYSE:TMO) will support Phase 3 manufacturing and clinical services, which suggests preparation for a later-stage trial. The company has said it will decide in the fourth quarter of 2026 whether to proceed to Phase 3.

Open-label studies, in which patients and investigators know the treatment, can be informative about safety and early signals but are less conclusive than randomized, controlled trials.

ARCT-810 in OTC deficiency

ARCT-810 targets ornithine transcarbamylase deficiency, a rare metabolic disorder. Phase 2 enrollment and dosing are complete. Arcturus is preparing an End-of-Phase 2 meeting covering adult and pediatric development, and it expects to share data and a regulatory plan in the third quarter of 2026.

Sector context

Messenger RNA developers operate in a crowded field, and demand for COVID-19 vaccines has changed considerably since the pandemic. Partnership income also tends to arrive irregularly, through upfront payments and milestones, which makes quarterly revenue lumpy. For a company of this size, the practical test is whether clinical data can attract new funding or partners before cash runs low.

Risks

Clinical programs can fail, enrollment can slow and regulators may ask for additional data. Revenue is small and uneven, so losses are likely to continue. The company may need further capital, which could dilute shareholders. Rights to KOSTAIVE are subject to existing partnership arrangements, and commercial success of a COVID-19 vaccine is uncertain. The company reports no dividend.