---
schema_version: "secwatch.filing_event.v1"
accession: "0001193805-23-000619"
form_type: "8-K"
ticker: "ARCT"
cik: "0001768224"
company_name: "Arcturus Therapeutics Holdings Inc."
filed_at: "2023-04-28T23:59:59+00:00"
generated_at: "2026-06-16T06:38:45.187961+00:00"
event_type: "regulatory"
sentiment: "positive"
materiality_score: 0.6
calibrated_materiality_score: 0.6
confidence: "high"
source: SEC EDGAR
---

# Meiji submits NDA in Japan for ARCT-154, Arcturus' self-amplifying mRNA COVID-19 vaccine

## Summary
- Meiji Seika Pharma filed NDA for primary immunization (two doses) of ARCT-154 in Japan.
- NDA based on Phase III trial in Vietnam (NCT05012943) with >16,000 subjects; met primary endpoint of COVID-19 prevention.
- Meiji holds exclusive Japan distribution rights from CSL Seqirus; Arcturus developed the vaccine.
- ARCT-154 uses next-gen mRNA technology for strong immune response and potential lower dosing.
- Meiji collaborates with ARCALIS to build mRNA manufacturing in Minami-soma, Fukushima.

## SEC filing metadata
- accession: 0001193805-23-000619
- form_type: 8-K
- ticker: ARCT
- cik: 0001768224
- company_name: Arcturus Therapeutics Holdings Inc.
- filed_at: 2023-04-28T23:59:59+00:00
- event_type: regulatory
- sentiment: positive
- materiality_score: 0.6
- calibrated_materiality_score: 0.6
- confidence: high
- sec_items: 7.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1768224/000119380523000619/0001193805-23-000619-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1768224/000119380523000619/e618558_8k-arct.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001193805-23-000619
- JSON: https://secwatch.observer/filing/0001193805-23-000619.json
- Plain text: https://secwatch.observer/filing/0001193805-23-000619.txt

This AI-assisted summary is a reading aid. Review the linked SEC EDGAR filing before relying on any specific claim.