Arcturus Therapeutics Announces Second Quarter 2021 Financial Results and mRNA Vaccine and Therapeutics Pipeline Progress ARCT-021, Arcturus' single shot STARR mRNA COVID vaccine, to begin multinational placebo-controlle

Therapeutics Announces Second Quarter 2021 Financial Results and mRNA Vaccine and Therapeutics Pipeline Progress

ARCT-021, Arcturus' single shot STARR

mRNA COVID vaccine, to begin multinational placebo-controlled Phase 3 efficacy study funded and sponsored by a global entity

ARCT-154, Arcturus' STARR mRNA

vaccine candidate targeting COVID variants of concern, elicits robust neutralizing antibody titers against all variants tested in primates,

including the Delta variant

ARCT-154 to begin staged Phase 3 study in Vietnam;

potential for EUA in December

Investor conference call at 4:30 p.m. ET today

San Diego, Calif, August 9, 2021 -

Arcturus Therapeutics Holdings Inc. (the "Company", "Arcturus", Nasdaq: ARCT), a leading clinical-stage messenger

RNA medicines company focused on the development of infectious disease vaccines and significant opportunities within liver and respiratory

rare diseases, today announced its financial results for the second quarter ended June 30, 2021 and provided corporate updates.

"This has been an exceptionally productive

period where Arcturus has made substantial progress with our mRNA-based vaccine and therapeutic platforms. We are excited about the imminent

initiation of the global Phase 3 vaccine trial of ARCT-021, which is funded by a global entity. We made excellent progress advancing and

partnering ARCT-154, our next generation vaccine, which targets SARS-CoV-2 variants, including the rapidly expanding and highly transmissible

Delta variant. In addition to the progress with our vaccine franchise, we've also advanced our therapeutics pipeline, with the approval

of a multiple dose Phase 2 study with ARCT-810, our systemically administered mRNA therapeutic candidate for individuals with OTC deficiency,"

said Joseph Payne, President and CEO of Arcturus.

Recent Corporate Highlights

ARCT-154 utilizes an optimized STARR

mRNA with multiple improvements, including modifications for stability and translation, increased immunogenicity of the spike protein

antigen via amino acid substitution, expressing the spike protein in a pre-fusion state, and inactivating the furin cleavage site.

Non-Human Primate (NHP) data collected one

month after second dose of 7.5 mcg; analysis of NHP serum was performed using non-replicating vesicular stomatitis virus pseudo-typed

with the spike protein of the SARS-CoV-2 variants of concern indicated. Titers (geometric mean) were determined by calculating the dilution

that resulted in 50% inhibition of cells expressing GFP encoded by the pseudovirus, a surrogate of virus infection. Error bars indicate

geometric standard deviation.

T cell responses for ARCT-021 and ARCT-154 are robust and similar

in non-human primates. Notably, STARR mRNA vaccines elicit similar T cell responses against all variants of concern tested. The

robust T cell responses are attributed to the self-amplifying mRNA mechanism of antigen expression.

T cell responses from non-human

primates assessed one month after second dose of 7.5 mcg; SARS-CoV-2 spike specific T cell responses were analyzed by ELISpot assay using

overlapping 15-mer peptides spanning the entire spike antigen from the ancestral SARS-CoV-2 strains or the Alpha, Beta, and Gamma variants

of concern. Spot Forming Units (SFU) were determined after background subtraction of unstimulated controls. Bars indicate mean values

and error bars indicate standard deviation.

Financial Results for the Quarter Ended June

Revenues in conjunction with strategic alliances

and collaborations: Arcturus' primary sources of revenues were from license fees and collaborative payments received from research

and development arrangements with pharmaceutical and biotechnology partners. For the three months ended June 30, 2021, the Company reported

revenue of $2.0 million compared with $2.3 million for the three months ended June 30, 2020.

Operating expenses: Total operating expenses for

the three months ended June 30, 2021, were $55.7 million compared with $12.4 million for the three months ended June 30, 2020 and $59.8

million for the three months ended March 31, 2021.

Research and development expenses increased by

approximately $37.7 million year over year in the second quarter ended June 30, 2021 due to increased personnel costs as well as expenses

related to our ARCT-810 and ARCT-021 programs. Research and development declined by approximately $5 million sequentially in the June

2021 quarter due primarily to the one-time $5 million exclusive license cost from Alexion Pharmaceuticals in the first quarter of 2021.

For the three months ended June 30, 2021, Arcturus

reported a net loss of approximately $54.6 million, or ($2.07) per basic and diluted share, compared with a net loss of $10.3 million,

or ($0.55) per basic and diluted share in the three months ended June 30, 2020.

The Company's cash balance totaled $433.6

million as of June 30, 2021, compared to a cash balance of $462.9 million at December 31, 2020. Subsequent to the end of the quarter,

the company received the remaining $30 million of our upfront payment from Vinbiocare. Based on our current pipeline, the Company's

cash position is expected to be sufficient to support operations for more than two years.

August 9th @ 4:30 p.m. ET

About Arcturus Therapeutics

Founded in 2013 and based in San Diego, California, Arcturus

Therapeutics Holdings Inc. (Nasdaq: ARCT) is a clinical-stage mRNA medicines and vaccines company with enabling technologies: (i)

LUNAR lipid-mediated delivery, (ii) STARR mRNA Technology and (iii) mRNA drug substance along with drug product manufacturing

expertise. Arcturus' diverse pipeline of RNA therapeutic and vaccine candidates includes mRNA vaccine programs for SARS-CoV-2 (COVID-19)

and Influenza, and other programs to potentially treat Ornithine Transcarbamylase (OTC) Deficiency, and Cystic Fibrosis along with partnered

programs including Glycogen Storage Disease Type 3, Hepatitis B Virus, and non-alcoholic steatohepatitis (NASH). Arcturus' versatile

RNA therapeutics platforms can be applied toward multiple types of nucleic acid medicines including messenger RNA, small interfering RNA,

replicon RNA, antisense RNA, microRNA, DNA, and gene editing therapeutics. Arcturus' technologies are covered by its extensive patent

portfolio (229 patents and patent applications, issued in the U.S., Europe, Japan, China and other countries).

Arcturus' commitment to the development of novel RNA therapeutics has led to collaborations with Janssen Pharmaceuticals, Inc.,

part of the Janssen Pharmaceutical Companies of Johnson & Johnson, Ultragenyx Pharmaceutical, Inc., Takeda Pharmaceutical Company

Limited, CureVac AG, Synthetic Genomics Inc., Duke-NUS Medical School, and the Cystic Fibrosis Foundation. For more information

visit www.ArcturusRx.com. In addition, please connect with us on Twitter and LinkedIn.

This press release contains forward-looking statements

that involve substantial risks and uncertainties for purposes of the safe harbor provided by the Private Securities Litigation Reform

Act of 1995. Any statements, other than statements of historical fact included in this press release, are forward-looking statements,

including those regarding strategy, future operations, collaborations, the planned initiation, design or completion of clinical trials,

anticipated sponsorship and/or funding of clinical trials of our candidates, the likelihood that the Company will obtain clearance from

regulatory authorities to proceed with planned clinical trials, the ability to enroll subjects in clinical trials, the likelihood that

preclinical or clinical data will be predictive of future clinical results, the likelihood that clinical data will be sufficient for regulatory

approval or completed in time to submit an application for regulatory approval within a particular timeframe, the anticipated timing for

regulatory submissions, the timing of, and expectations for, any results of any preclinical or clinical studies or regulatory approvals,

the likelihood of success (including safety and efficacy) of the Company's pipeline, including ARCT-021, ARCT-154 and ARCT-810,

the potential administration regimen or dosage, or ability to administer multiple doses of, any of the Company's drug candidates,

the Company's efforts to develop a vaccine against COVID-19 and therapeutic potential thereof based on the Company's mRNA

therapeutics, the Company's manufacturing methods and technologies, the likelihood that a patent will issue from any patent application,

its current cash position and adequacy of its capital to support future operations, and the impact of general business and economic conditions.

Actual results and performance could differ materially from those projected in any forward-looking statements as a result of many factors

including, without limitation, the ability to enroll subjects in clinical trials as a result of the COVID-19 pandemic, the impact of commercialization

of third-party COVID-19 vaccines on the design, and ability to conduct, clinical trials, the availability of manufacturing capacity and

raw materials, unexpected clinical results, government regulations impacting the regulatory environment or intellectual property landscape,

and general market conditions that may prevent such achievements or performance. Arcturus may not actually achieve the plans, carry out

the intentions or meet the expectations or projections disclosed in any forward-looking statements such as the foregoing and you should

not place undue reliance on such forward-looking statements. Such statements are based on management's current expectations and

involve risks and uncertainties, including those discussed under the heading "Risk Factors" in Arcturus' Annual Report

on Form 10-K for the fiscal year ended December 31, 2020, and in subsequent filings with, or submissions to, the SEC. Except as otherwise

required by law, Arcturus disclaims any intention or obligation to update or revise any forward-looking statements, which speak only as

of the date they were made, whether as a result of new information, future events or circumstances or otherwise.

Trademark Acknowledgements

The Arcturus logo and other trademarks of Arcturus appearing in this