Arcturus Therapeutics Holdings Inc. Q2 FY2026 earnings call

Clinical Development Progress

• ARCT 810 (OTC deficiency, rare disease): Completed enrollment and all study drug dosing for the ongoing Phase 2 study in the quarter, a key operational milestone. Current efforts focus on data review, preparation for regulatory interactions, and planning for an end-of-Phase 2 (EOP2) meeting to finalize the adult and pediatric development path.
• ARCT 032 (cystic fibrosis, rare disease): Phase 2 study enrollment is on schedule, with trial expansion to ex-US sites in Turkey and Israel to accelerate recruitment, which management expects will support sufficient patient enrollment by Q4 2026. Over 50 participants have received ARCT 032 at doses up to 15 milligrams for 28 days of daily dosing, without required steroid pre-treatment or clinic-based administration.
• Infectious disease vaccine portfolio: Arcturus has regained full strategic and development control of the portfolio following termination of the CSL collaboration. The pandemic flu candidate ARCT 2304 has completed Phase 1 testing under a BARDA grant, with study results accepted for publication in Nature Communications, and the company plans to request scientific advice from the EMA for a licensure pathway in Q4 2026. A Phase 1 trial for seasonal flu is also completed.

Financial and Strategic Updates

• Cash and cash equivalents totaled $191.5 million as of June 30, 2026, providing a cash runway through the end of 2028 (over two and a half years), enough to reach all key clinical and regulatory milestones for the rare disease pipeline.
• Thermo Fisher is the exclusive commercial manufacturing partner for the CF program, and the collaboration provides funding to support late-stage development of ARCT 032. The partnership followed a competitive process, and Thermo Fisher reviewed all available Phase 2 data under confidentiality before agreeing to the deal.
• Management maintains a disciplined approach to capital allocation focused on advancing core rare disease programs, with plans to explore partnering and commercial opportunities for the regained vaccine portfolio to self-fund further development.

Arcturus currently operates two core business segments: rare disease therapeutics and infectious disease vaccines. For the three months ended June 30, 2026, total company revenue was $3 million, down from $28.3 million year-over-year (YoY). For the six months ended June 30, 2026, total revenue was $5 million, down from $57.7 million YoY. The large YoY revenue decline is attributed to the wind-down of the collaboration agreement with CSL, as Arcturus progresses toward regaining full rights to its CoStave infectious disease vaccine portfolio, which contributes 100% of the current small revenue base from collaboration activities. The rare disease therapeutics segment (covering ARCT 032 for cystic fibrosis (CF) and ARCT 810 for ornithine transcarbamylase (OTC) deficiency) has not yet generated commercial revenue, and all current segment activity is funded by internal cash and the Thermo Fisher collaboration for late-stage CF development. Research and development (R&D) expenses for Q2 2026 were $17.5 million ($39 million H1 2026), down from $29.6 million ($64.5 million H1 2025) YoY, driven by disciplined cost cutting across all segments. General and administrative expenses were $11 million in Q2 2026 ($20.5 million H1 2026), relatively flat compared to $10.3 million ($21.7 million H1 2025) YoY.

• For the ARCT 810 (OTC deficiency) program, management plans to release full Phase 2 data (including both U.S. and European patient data, plus supplementary FDA-requested Type C meeting data) and disclose the full regulatory development plan in Q3 2026.
• For the ARCT 032 (cystic fibrosis) program, management reaffirmed guidance that a Phase 3 go/no-go decision will be made in Q4 2026, once sufficient cumulative data has been collected; no interim public data disclosure is planned before this decision.
• For the pandemic flu vaccine candidate ARCT 2304, management guidance indicates the company will pursue EMA scientific advice for a licensure pathway in Q4 2026. ARCT 2304 study results will be published shortly in Nature Communications.
• All guidance is maintained from prior quarters, with no upward or downward revisions to key clinical milestone timelines.

• Rare disease trials face inherent enrollment risk, which the company mitigated by expanding trial sites to Israel and Turkey for the ARCT 032 Phase 2 study, but enrollment delays could still push back the Q4 2026 go/no-go decision.
• Inhaled mRNA therapeutics for CF have historically faced high failure rates due to tolerability and toxicology issues, even with Arcturus' observed positive safety profile to date, adverse safety signals could emerge in longer 12-week dosing.
• Success of the ARCT 032 program depends on interpreting novel endpoints (including Lung Clearance Index (LCI)) that lack established normative data for adult CF patients; while the company expects to use data from the CF Foundation's REACH study as a control, a lack of clear efficacy signals across endpoints could lead to a no-go decision.
• Monetization of the regained vaccine portfolio depends on successfully securing new partnerships, which may not materialize on favorable terms or at all; maintaining the portfolio could increase R&D expenses if new partnerships are not secured.

Q: What data will be included in the upcoming Q3 2026 ARCT 810 readout, and what endpoints define success for the program?

A: The readout will include a full dataset of Phase 2 data from both U.S. and European patients, plus the supplementary FDA-requested data from the earlier Type C meeting, alongside a full update on the regulatory path forward. Success will be judged by the totality of data, including safety/tolerability, key biomarkers (ammonia, glutamine, urea), quality of life, and functional patient outcomes, not just any single endpoint like diet liberalization.

Q: What is the enrollment cadence for the ARCT 032 Phase 2 study, what data will be available for the Q4 2026 go/no-go decision, and what is the current safety profile?

A: Expansion to Israel and Turkey has accelerated enrollment, and management is confident enough data will be accumulated by Q4 2026 to make a decision. The decision will be based on cumulative data for FEV1, LCI, high-res CT scans, and validated quality of life measures. To date, over 50 participants have received up to 15mg daily dosing for 28 days without required steroids or clinic administration, with no observed serious safety signals, giving management high confidence in the platform's tolerability.

Q: What endpoints will the company use to decide whether to move ARCT 032 into Phase 3, and could the program move forward based on non-FEV1 data?

A: This is the first program for this unique class of CF patients, so there are no pre-set historical success thresholds. The untreated patient population experiences a 1-2% annual decline in predicted FEV1, so stabilization alone would be a meaningful step forward. The decision will consider the totality of data, including FEV1, LCI, CT findings, patient quality of life, and functional outcomes, so a program advance based on positive non-FEV1 data is possible.

Q: Now that the vaccine portfolio has been returned to Arcturus, how will the company fund maintenance and monetization, and what is the clinical status of non-CoStave vaccine programs?

A: The company will pursue two paths to fund the portfolio: proactive commercial expansion (including supporting Meiji in Japan and exploring opportunities in Europe/UK) and business development partnerships for the portfolio, which includes high-value targets like seasonal flu, pandemic flu, RSV, EBV, and HMPV. The Phase 1 trial for pandemic flu ARCT 2304 is complete, results are accepted for publication, and EMA scientific advice is planned for Q4 2026; a Phase 1 seasonal flu trial is also completed.