Phio Pharmaceuticals Reports 2021 Year End Financial Results and Provides Business Update Company transitioning into a clinical stage company with start of the first clinical study for lead program, PH-762. Marlborough,

Pharmaceuticals Reports 2021 Year End Financial Results and Provides Business Update

Company transitioning

into a clinical stage company with start of the first clinical study for lead program, PH-762.

Marlborough, Mass., March 22, 2022/PRNewswire/

-- Phio Pharmaceuticals Corp. (Nasdaq: PHIO), a clinical stage biotechnology company developing the next generation of therapeutics based

on its proprietary self-delivering RNAi (INTASYL ) therapeutic platform, today reported its financial results for the year ended

December 31, 2021 and provided a business update.

"Over the past year, we have made significant progress moving

towards the initiation of our first-in-human clinical studies for our lead program, PH-762, in 2022. Currently, we are on track to start

enrolling patients in the first of these trials, a Phase 1b study of PH-762 in advanced melanoma, in the coming weeks," said Dr.

Gerrit Dispersyn, President and CEO of Phio. "I am proud of the Phio team's execution of our preclinical program for PH-762,

which has generated a steady stream of positive data and supported our regulatory strategy. These studies were conducted during the second

year of the ongoing global pandemic, which has proven to be a difficult period of time for the team, yet we incurred only minor delays

to our original timelines. I believe the achievement of these milestones within the stated timeframes speak to the strength of our team

and the assets in our pipeline, as well as our INTASYL platform. We look forward to continuing to deliver on our current development pipeline

in 2022 as our business fulfills its transition into a clinical stage company."

Quarter in Review and Recent Corporate Updates

Upcoming Pipeline Milestones for 2022

At December 31, 2021, the Company had cash

of $24.1 million as compared with $14.2 million at December 31, 2020. The Company expects its current cash will be sufficient to fund

currently planned operations to the second quarter of 2023.

Research and Development Expenses

Research and development expenses were approximately

$8.9 million for the year ended December 31, 2021, compared to approximately $3.7 million for the year ended December 31, 2020. The increase

in research and development expenses was primarily due to manufacturing costs for the Company's PH-762 and PH-894 INTASYL compounds,

fees for the required preclinical studies in support of the Company's clinical trials for PH-762 and CRO and consulting related

costs to support the initiation of the Company's clinical trials as compared to the same period in the prior year.

General and Administrative Expenses

General and administrative expenses were approximately

$4.6 million for the year ended December 31, 2021, compared to approximately $5.1 million for the year ended December 31, 2020. The decrease

in general and administrative expenses was primarily due to a decrease in patent and legal fees partially offset by increases in the use

of an outside consultant to support business development activities and corporate insurance premiums.

Net loss was $13.3 million, or $1.04 per share,

for the year ended December 31, 2021, compared with $8.8 million, or $1.92 per share, for the year ended December 31, 2020. The increase

in net loss was primarily attributable to the increase in research and development expenses related to the Company's manufacturing

of its INTASYL compounds and preclinical activities in preparation for the start of its clinical trial with PH-762, as described above.

The change in net loss per share was primarily due to an increase in the number of shares outstanding as a result of the Company's

capital raise activities as compared to the prior year period.

About Phio Pharmaceuticals

Phio Pharmaceuticals Corp. (Nasdaq: PHIO) is a clinical stage biotechnology

company developing the next generation of immuno-oncology therapeutics based on its self-delivering RNAi (INTASYL ) therapeutic

platform. The Company's efforts are focused on silencing tumor-induced suppression of the immune system through its proprietary INTASYL

platform with utility in immune cells and the tumor micro-environment. Our goal is to develop powerful INTASYL therapeutic compounds that

can weaponize immune effector cells to overcome tumor immune escape, thereby providing patients a powerful new treatment option that goes

beyond current treatment modalities. For additional information, visit the Company's website, www.phiopharma.com.

Forward Looking Statements

This press release contains forward-looking statements within the meaning

of the Private Securities Litigation Reform Act of 1995. Forward-looking statements can be identified by words such as "intends,"

"believes," "anticipates," "indicates," "plans," "expects," "suggests," "may,"

"would," "should," "potential," "designed to," "will," "ongoing," "estimate,"

"forecast," "target," "predict," "could" and similar references, although not all forward-looking

statements contain these words. Forward-looking statements are neither historical facts nor assurances of future performance. These statements

are based only on our current beliefs, expectations and assumptions regarding the future of our business, future plans and strategies,

projections, anticipated events and trends, the economy and other future conditions. Because forward-looking statements relate to the

future, they are subject to inherent uncertainties, risks and changes in circumstances that are difficult to predict and many of which

are outside of our control. Our actual results may differ materially from those indicated in the forward-looking statements as a result

of a number of important factors, including, but not limited to, the impact to our business and operations by the ongoing coronavirus

pandemic, the development of our product candidates, results from our preclinical and clinical activities, our ability to execute on business

strategies, our ability to develop our product candidates with collaboration partners, and the success of any such collaborations, the

timeline and duration for advancing our product candidates into clinical development, the timing or likelihood of regulatory filings and

approvals, the success of our efforts to commercialize our product candidates if approved, our ability to manufacture and supply our product

candidates for clinical activities, and for commercial use if approved, the scope of protection we are able to establish and maintain

for intellectual property rights covering our technology platform, our ability to obtain future financing, market and other conditions

and those identified in our Annual Report on Form 10-K and subsequent Quarterly Reports on Form 10-Q under the caption "Risk Factors"

and in other filings the Company periodically makes with the SEC. Readers are urged to review these risk factors and to not act in reliance

on any forward-looking statements, as actual results may differ from those contemplated by our forward-looking statements. Phio does not

undertake to update forward-looking statements to reflect a change in its views, events or circumstances that occur after the date of

this release, except as required by law.

Contact Phio Pharmaceuticals Corp.

PHIO PHARMACEUTICALS CORP.

CONSOLIDATED STATEMENTS OF OPERATIONS

(Amounts in thousands, except share and per

PHIO PHARMACEUTICALS CORP.

CONSOLIDATED BALANCE SHEETS

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