Phio Pharmaceuticals : HCW 23rd Annual Global Investment Conference Presentation

DEVELOPING THE NEXT GENERATION

of immuno-oncology therapeutics

September 2021

w w w. phiopharma. com I Ticker: PHIO (NASDAQ)

Forward Looking Statements

This presentation contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995.

Words such as "believes," "anticipates," "plans," "expects," "indicates," "will," "intends," "potential," "suggests" and similar expressions

are intended to identify forward-looking statements. These statements are based on Phio Pharmaceuticals Corp.'s (the "Company") current beliefs and expectations. Such statements include, but are not limited to, statements about the impact to our business and operations by the ongoing coronavirus pandemic, the development of our product candidates, the expected timing of certain developmental milestones (including timing or likelihood of regulatory filings and approvals), results from our preclinical and clinical studies, potential partnership opportunities, and the success of any such opportunities, the Company's competition and market opportunity and pro forma estimates. The inclusion of forward-looking statements should not be regarded as a representation by the Company that any of its plans will be achieved. Actual results may differ from those set forth in this presentation due to risks and uncertainties in the Company's business, including those identified under "Risk Factors" in the Company's most recently filed Annual Report on Form 10-K and in other filings the Company periodically makes with the U.S. Securities and Exchange Commission. The Company does not undertake to update any of these forward-looking statements to reflect a change in its views or events or circumstances that occur after the date of this presentation.

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Immuno-oncology

Unmet Need

Immuno-oncology: Definition and key unmet needs

Immuno-oncology is the science of harnessing a patient's immune system to better

recognize and attack cancer cells, through:

Unmet need

Cell therapy

e.g. CAR-T adoptive cell therapy (ACT)

• Limited activity in solid tumors
• Cost

Unmet need

Systemic immune stimulating therapy

e.g. checkpoint inhibitors

• High rate of non-responders & relapse
• Immune related adverse events

Solutions include:

"Reprogramming" cells for ACT	"Reprogramming" tumor microenvironment
- Activate the otherwise dysfunctional immune	- Remove the barriers of the tumor immune
cells	microenvironment

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Various adoptive cell therapies share similar issues

Adoptive

Cell

Therapy

1. cells
   NK cells

Tumor Infiltrating Lymphocytes

TCR-T cells

CAR-T cells

Stimulated NK cells

CAR-NK cells

Regardless of source / lineage, manufacturing manipulations often lead to dysfunctional features including:

•	Terminal differentiation	•	Senescence
•	Exhaustion	•	Suboptimal metabolism

"Dysfunctional features induced during laboratory-based manipulations of immune products prior to adoptive

cell transfer has a determining effect on outcomes"

Alter cell phenotype:	Combination therapies
-	Checkpoints & co-inhibitory signals	- Immunomodulation
-	Metabolic programing	-	Immune cells
-	Epigenetic programing	-	Tumor cells

During manufacturing

After manufacturing

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