Form 424B3 - Prospectus [Rule 424(b)(3)]

Filed pursuant to Rule 424(b)(3)

Registration No. 333-276146

Prospectus

Up to 4,420,273 Shares of Common Stock

Pursuant to this prospectus, the selling stockholders identified herein (the “Selling Stockholders”) are offering on a resale basis an aggregate of up to 4,420,273 shares of common stock of Phio Pharmaceuticals Corp. (the “Company,” “we,” “us” or “our”), par value $0.0001 per share (the “Common Stock) consisting of (a) up to an aggregate of 2,270,320 shares of Common Stock that are issuable upon exercise of warrants with a five and one-half year term (“Series A Warrants”), (b) up to an aggregate of 1,990,184 shares of Common Stock that are issuable upon exercise of warrants with an eighteen month term (the “Series B Warrants”), in each case issued pursuant to an inducement letter agreement by and among us and the Selling Stockholders, dated December 6, 2023 (the “Inducement Letter Agreement”), and (c) up to 159,769 shares of Common Stock that are issuable upon the exercise of certain warrants (together with the Series A Warrants and the Series B Warrants, the “Warrants”) issued to our placement agent pursuant to an engagement letter in connection with the Inducement Letter Agreement and the offerings contemplated thereunder.

We will not receive any of the proceeds from the sale by the Selling Stockholders of the Common Stock. Upon any exercise of the Warrants by payment of cash, however, we will receive the exercise price of the Warrants, which, if exercised in cash with respect to the 4,420,273 shares of Common Stock offered hereby, would result in gross proceeds to us of approximately $4.9 million. However, we cannot predict when and in what amounts or if the Warrants will be exercised by payments of cash and it is possible that the Warrants may expire and never be exercised, in which case we would not receive any cash proceeds.

The Selling Stockholders may sell or otherwise dispose of the Common Stock covered by this prospectus in a number of different ways and at varying prices. We provide more information about how the Selling Stockholders may sell or otherwise dispose of the Common Stock covered by this prospectus in the section entitled “Plan of Distribution” on page 9. Discounts, concessions, commissions and similar selling expenses attributable to the sale of Common Stock covered by this prospectus will be borne by the Selling Stockholders. We will pay all expenses (other than discounts, concessions, commissions and similar selling expenses) relating to the registration of the Common Stock with the Securities and Exchange Commission (the “SEC”).

Our Common Stock is listed on The Nasdaq Capital Market under the symbol “PHIO.” On December 26, 2023, the last reported sale price of our Common Stock on The Nasdaq Capital Market was $0.756 per share.

Investing in our securities involves a high degree of risk. Before making any investment in these securities, you should consider carefully the risks and uncertainties described in the section entitled “Risk Factors” beginning on page 6 of this prospectus.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or determined if this prospectus is truthful or complete. Any representation to the contrary is a criminal offense.

The date of this prospectus is December 27, 2023

TABLE OF CONTENTS

About this Prospectus	ii

Cautionary Note Regarding Forward-Looking Statements	iii

Prospectus Summary	1

The Offering	5

Risk Factors	6

Use of Proceeds	6

Dividend Policy	6

Determination of Offering Price	6

Selling Stockholders	7

Plan of Distribution	9

Description of Securities to be Registered	11

Legal Matters	13

Experts	13

Where You Can Find More Information	13

Incorporation of Certain Information by Reference	14

ABOUT THIS PROSPECTUS

This prospectus relates to the resale by the Selling Stockholders identified in this prospectus under the caption “Selling Stockholders,” from time to time, of up to an aggregate of 4,420,273 shares of Common Stock. We are not selling any shares of Common Stock under this prospectus, and we will not receive any proceeds from the sale of shares of Common Stock offered hereby by the Selling Stockholders, although we may receive cash from the exercise of the Warrants.

You should rely only on the information provided in this prospectus, including any information incorporated by reference. We have not authorized anyone to provide you with any other information and we take no responsibility for, and can provide no assurances as to the reliability of, any other information that others may give you. The information contained in this prospectus speaks only as of the date set forth on the cover page and may not reflect subsequent changes in our business, financial condition, results of operations and prospects.

We are not, and the Selling Stockholders are not, making offers to sell these securities in any jurisdiction in which an offer or solicitation is not authorized or permitted or in which the person making such offer or solicitation is not qualified to do so or to any person to whom it is unlawful to make such an offer or solicitation. You should read this prospectus, including any information incorporated by reference, in its entirety before making an investment decision. You should also read and consider the information in the documents to which we have referred you in the sections entitled “Where You Can Find More Information” and “Incorporation of Certain Information by Reference.”

In this prospectus, unless otherwise noted, (1) the term “Phio” refers to Phio Pharmaceuticals Corp. and our subsidiary, MirImmune, LLC and (2) the terms “Company,” “we,” “us” and “our” refer to the ongoing business operations of Phio and MirImmune, LLC, whether conducted through Phio or MirImmune, LLC.

CAUTIONARY NOTE REGARDING FORWARD-LOOKING STATEMENTS

This prospectus 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. Risks that could cause actual results to vary from expected results expressed in our forward-looking statements include, but are not limited to:

	·	we are dependent on the success of our INTASYL™ technology platform, and our product candidates based on this platform, which is unproven and may never lead to approved and marketable products;
	·	our product candidates are in an early stage of development and we may fail, experience significant delays, never advance in clinical development or not be successful in our efforts to identify or discover additional product candidates, which may materially and adversely impact our business;
	·	we are dependent on collaboration partners for the successful development of our adoptive cell therapy product candidates;
	·	if we experience delays or difficulties in identifying and enrolling subjects in clinical trials, it may lead to delays in generating clinical data and the receipt of necessary regulatory approvals;
	·	topline data may not accurately reflect or may materially differ from the complete results of a clinical trial;
	·	we rely upon third parties for the manufacture of the clinical supply for our product candidates;
	·	we are dependent on the patents we own and the technologies we license, and if we fail to maintain our patents or lose the right to license such technologies, our ability to develop new products would be harmed;
	·	we will require substantial additional funds to complete our research and development activities;
	·	future financing may be obtained through, and future development efforts may be paid for by, the issuance of debt or equity, which may have an adverse effect on our stockholders or may otherwise adversely affect our business; and
	·	the price of our Common Stock has been and may continue to be volatile.

The risks set forth above are not exhaustive and additional factors, including those identified in this prospectus under the heading “Risk Factors,” for reasons described elsewhere in this prospectus and in other filings Phio Pharmaceuticals Corp. periodically makes with the Securities and Exchange Commission, including the other risks identified in Item 1A. Risk Factors in our Annual Report on Form 10-K for the year ended December 31, 2022, could adversely affect our business and financial performance. Therefore, you should not rely unduly on any of these forward-looking statements. Forward-looking statements contained in this prospectus speak as of the date hereof and Phio Pharmaceuticals Corp. 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 report, except as required by law.

iii

Prospectus Summary

The following summary highlights certain information contained elsewhere in this prospectus and the documents incorporated by reference herein. This summary provides an overview of selected information and does not contain all of the information you should consider in making your investment decision. Therefore, you should read the entire prospectus and the documents incorporated by reference herein carefully before investing in our securities. Investors should carefully consider the information set forth under “Risk Factors” beginning on page 6 of this prospectus and the financial statements and other information incorporated by reference in this prospectus. In this prospectus, unless otherwise noted, (1) the term “Phio” refers to Phio Pharmaceuticals Corp. and our subsidiary, MirImmune, LLC and (2) the terms “Company,” “we,” “us,” and “our” refer to the ongoing business operations of Phio and MirImmune, LLC, whether conducted through Phio or MirImmune, LLC.

Overview

Phio is a clinical stage biotechnology company whose proprietary INTASYL™ self-delivering RNAi technology platform is designed to make immune cells more effective in killing tumor cells. We are developing therapeutics that are designed to leverage INTASYL to precisely target specific proteins that reduce the body’s ability to fight cancer, without the need for specialized formulations or drug delivery systems.

INTASYL Platform

Overall, RNA is involved in the synthesis, regulation and expression of proteins. RNA takes the instructions from DNA and turns those instructions into proteins within the body’s cells. RNA interference, or RNAi, is a biological process that inhibits the expression of genes or the production of proteins. Diseases are often related to the incorrect protein being made, excessive amounts of a specific protein being made, or the correct protein being made, but at the wrong location or time. RNAi offers a novel approach to drug development because RNAi compounds can be designed to silence any one of the thousands of human genes, many of which are considered “undruggable” by traditional therapeutics.

Our development efforts are based on our proprietary INTASYL self-delivering RNAi technology platform. INTASYL compounds are designed to precisely target specific proteins that reduce the body’s ability to fight cancer, without the need for specialized formulations or drug delivery systems, and are designed to make immune cells more effective in killing tumor cells. Our efforts are focused on developing immuno-oncology therapeutics using our INTASYL platform. We have demonstrated preclinical efficacy in both direct-to-tumor injection and adoptive cell therapy (“ACT”) applications with our INTASYL compounds.

Since the initial discovery of RNAi, drug delivery has been the primary challenge in developing RNAi-based therapeutics. Other siRNA technologies require cell targeting chemical conjugates which limit delivery to specific cell types. INTASYL is based on proprietary chemistry that is designed to maximize the activity and adaptability of the compound and is unique in that it can be delivered to any cell type or tissue without the need to modify the chemistry. This is designed to eliminate the need for formulations or delivery systems (for example, nanoparticles or electroporation). This provides efficient, spontaneous, cellular uptake with potent, long-lasting intracellular activity.

We believe that our INTASYL platform provides the following benefits including, but not limited to:

	·	Ability to target a broad range of cell types and tissues;
	·	Ability to target both intracellular and extracellular protein targets;
	·	Efficient uptake by target cells, avoiding the need for assisted delivery;
	·	Sustained, or long-term, effect in vivo;
	·	Ability to target multiple genes in one drug product;
	·	Favorable clinical safety profile with local administration; and
	·	Readily manufactured under current good manufacturing practices.

PH-762

PH-762 is an INTASYL compound designed to reduce the expression of cell death protein 1 (“PD-1”). PD-1 is a protein that inhibits T cells’ ability to kill cancer cells and is a clinically validated target in immunotherapy. Decreasing the expression of PD-1 can thereby increase the capacity of T cells, which protect the body from cancer cells and infections, to kill cancer cells.

Our preclinical studies have demonstrated that direct-to-tumor application of PH-762 resulted in potent anti-tumoral effects and have shown that direct-to-tumor treatment with PH-762 inhibits tumor growth in a dose dependent fashion in PD-1 responsive and refractory models. Importantly, direct-to-tumor administration of PH-762 resulted in activity against distant untreated tumors, indicative of a systemic anti-tumor response. We believe these data further support the potential for PH-762 to provide a strong local immune response without the dose immune-related adverse effects seen with systemic antibody therapy.

In November 2023, we announced the first patient dosed in our U.S. multi-center Phase 1b clinical trial with PH-762 under a previously cleared Investigational New Drug (“IND”) application by the U.S. Food and Drug Administration. Intratumoral injection of PH-762 in this dose-escalating trial will treat patients with cutaneous squamous cell carcinoma, melanoma and Merkel cell carcinoma and is currently open for continued enrollment of patients. This trial is designed to evaluate the safety and tolerability of neoadjuvant use of intratumorally injected PH-762, assess the tumor response, and determine the dose or dose range for continued study of PH-762.

Given our intention to focus our efforts and resources on our U.S. clinical trial with PH-762, we have completed the winding down process for our first-in-human clinical trial for PH-762 in France, which was limited to the treatment of patients with metastatic melanoma. Safety data from the initial cohort of three patients in the French clinical trial were evaluated by a data monitoring committee in the first quarter of 2023. The safety data review disclosed no dose-limiting toxicity, and no drug-related severe or serious adverse events.

Due to INTASYL’s ease of administration, we have shown that our compounds can easily be incorporated into current ACT manufacturing processes. In ACT, T cells are usually taken from a patient's own blood or tumor tissue, grown in large numbers in a laboratory, and then given back to the patient to help the immune system fight cancer. By treating T cells with our INTASYL compounds while they are being grown in the laboratory, we believe our INTASYL compounds can improve these immune cells to make them more effective in killing cancer. Preclinical data generated in collaboration with AgonOx, Inc. (“AgonOx”), a private company developing a pipeline of novel immunotherapy drugs targeting key regulators of the immune response to cancer, demonstrated that treating AgonOx’s “double positive” tumor infiltrating lymphocytes (“DP TIL”) with PH-762 increased by two-fold their tumor killing activity.

In March 2021, we entered into a clinical co-development collaboration agreement (the “Clinical Co-Development Agreement”) with AgonOx to develop a T cell-based therapy using PH-762 and AgonOx’s DP TIL. Under the Clinical Co-Development Agreement, we committed to provide financial support for development costs of up to $4 million to AgonOx for expenses incurred to conduct a Phase 1 clinical trial of PH-762 treated DP TIL in patients with advanced melanoma and other advanced solid tumors. We are also eligible to receive certain future development milestones and low single-digit sales-based royalty payments from AgonOx’s licensing of its DP TIL technology.

PH-762 treated DP TIL are being evaluated in a Phase 1 clinical trial in the United States with up to 18 patients with advanced melanoma and other advanced solid tumors by AgonOx. The primary trial objectives are to evaluate the safety and to study the potential for enhanced therapeutic benefit from the administration of PH-762 treated DP TIL. We announced the first patient was dosed in August 2023 and the trial is open for the continued enrollment of patients. As of September 30, 2023, there was approximately $3.0 million of remaining costs not yet incurred under the Clinical Co-Development Agreement.

PH-894

PH-894 is an INTASYL compound that is designed to silence BRD4, a protein that controls gene expression in both T cells and tumor cells, thereby effecting the immune system as well as the tumor. Intracellular and/or commonly considered “undruggable” targets, such as BRD4, represent a challenge for small molecule and antibody therapies. Therefore, what sets this compound apart is its dual mechanism: PH-894 suppression of BRD4 in T cells results in T cell activation, and suppression of BRD4 in tumor cells results in tumors becoming more sensitive to being killed by T cells.

Preclinical studies conducted have demonstrated that PH-894 resulted in a strong, concentration dependent and durable silencing of BRD4 in T cells and in various cancer cells. Similar to PH-762, preclinical studies have also shown that direct-to-tumor application of PH-894 resulted in potent and statistically significant anti-tumoral effects against distant untreated tumors, indicative of a systemic anti-tumor response. These preclinical data indicate that PH-894 can reprogram T cells and other cells in the tumor microenvironment to provide enhanced immunotherapeutic activity. We have completed the IND-enabling studies and are in the process of continuing to finalize the study reports required for an IND submission with PH-894. As a result of the reprioritization to advance our clinical trial with PH-762 in the U.S., we have elected to defer the IND submission for PH-894.

December 2023 Offering

On December 6, 2023, we entered into an inducement letter agreement (the “Inducement Letter Agreement”) with certain holders (the “Warrant Holders”) of certain of our existing warrants to purchase up to an aggregate of 2,130,252 shares of the Company’s common stock, $0.0001 par value (the “Common Stock”), originally issued to the Selling Stockholders on dates between October 2018 and June 2023 with an exercise price of $5.40 or $4.03 per share, as applicable (the “Existing Warrants”).

Pursuant to the Inducement Letter Agreement, the Warrant Holders agreed to exercise for cash the Existing Warrants at a reduced exercise price of $1.33 per share in consideration of the Company’s agreement to issue new unregistered Series A Warrants (the “Series A Warrants”) to purchase up to 2,270,320 shares of Common Stock and new unregistered Series B Warrants (the “Series B Warrants” and, together with the Series A Warrants, the “New Warrants”) to purchase up to 1,990,184 shares of Common Stock (collectively, the “New Warrant Shares”), issued and sold at a price of $0.125 per New Warrant (which purchase price was included in the reduced $1.33 per share exercise price of the Existing Warrants). The Series A Warrants have an exercise price of $1.08 per share, were exercisable immediately upon issuance and have a term of five and one-half years from the date of issuance. The Series B Warrants have an exercise price of $1.08 per share, were exercisable immediately upon issuance and have a term of eighteen months from the date of issuance.

Pursuant to the terms of the Inducement Letter Agreement, in the event that the exercise of the Existing Warrants would have otherwise caused a Warrant Holder to exceed the beneficial ownership limitations set forth in such Warrant Holder’s Existing Warrants (4.99% or, if applicable and at such Warrant Holder’s election, 9.99%), we issued to such Warrant Holder the number of shares of Common Stock that would not cause such Warrant Holder to exceed such beneficial ownership limitation, as directed by such Warrant Holder, and agreed to hold such Warrant Holder’s balance of shares of Common Stock in abeyance until we receive notice from such Warrant Holder that the balance of shares of Common Stock may be issued in compliance with such beneficial ownership limitations. Accordingly, an aggregate of 826,370 shares of Common Stock were held in abeyance (the “Abeyance Shares”) for such Warrant Holders, with such Abeyance Shares evidenced through such Warrant Holders’ Existing Warrants, which Warrant Holders’ Existing Warrants shall be deemed prepaid and may be exercised pursuant to a notice of exercise from the applicable Warrant Holder.

The net proceeds to us from the exercise of the Existing Warrants were approximately $2.4 million, after deducting placement agent fees and offering expenses. The closing of the offering occurred on December 8, 2023.

Pursuant to an engagement letter, dated as of October 31, 2023 and as amended on December 6, 2023 (the “Engagement Letter”), between us and H.C. Wainwright & Co., LLC (“Wainwright”), we agreed to pay Wainwright (i) an aggregate cash fee equal to 7.5% of the gross proceeds from the exercise of the Existing Warrants and (ii) a management fee equal to 1.0% of the aggregate gross proceeds from the exercise of the Existing Warrants. We also agreed to pay Wainwright $35,000 for non-accountable expenses, $50,000 for accountable expenses and $15,950 for clearing fees. Additionally, we agreed to issue to Wainwright or its designees as compensation, warrants to purchase up to 159,769 shares of Common Stock, equal to 7.5% of the aggregate number of Existing Warrants exercised in the offering (the “Placement Agent Warrants” and, together with the Series A Warrants and the Series B Warrants, the “Warrants”). The Placement Agent Warrants have a term of five and one half years from the closing of the offering and an exercise price of $1.66 per share of Common Stock.

Corporate Information

The Company was incorporated in the state of Delaware in 2011 as RXi Pharmaceuticals Corporation. On November 19, 2018, we changed our name to Phio Pharmaceuticals Corp., to reflect our transition from a platform company to one that is fully committed to developing groundbreaking immuno-oncology therapeutics. Our executive offices are located at 257 Simarano Drive, Suite 101, Marlborough, MA 01752, and our telephone number is (508) 767-3861. Our website address is http://www.phiopharma.com. Our website and the information contained on that site, or connected to that site, is not part of or incorporated by reference into this prospectus.

THE OFFERING

The Selling Stockholders identified in this prospectus are offering on a resale basis up to 4,420,273 shares of Common Stock issuable upon exercise of the Warrants, as more fully described above.

Common Stock to be offered by the Selling Stockholders		Up to 4,420,273 shares of Common Stock

Common Stock outstanding prior to this offering		2,307,385 shares of Common Stock as of September 30, 2023

Common Stock to be outstanding after this offering		8,031,540¹ shares of Common Stock

Use of proceeds:		We will not receive any proceeds from the sale of the shares of Common Stock by the Selling Stockholders, except for the Warrant exercise price paid for the Common Stock offered hereby and issuable upon the exercise of the Warrants. See “Use of Proceeds” on page 7 of this prospectus.

Risk factors:		You should read the “Risk Factors” section beginning on page 6 of this prospectus for a discussion of factors to consider carefully before deciding to invest in shares of our securities.

Nasdaq Capital Market symbol:		Our Common Stock is listed on The Nasdaq Capital Market under the symbol “PHIO.” We do not intend to apply for listing of the Warrants on any securities exchange or nationally recognized trading system.

¹The number of shares of Common Stock to be outstanding after this offering is based on 2,307,385 shares of Common Stock outstanding as of September 30, 2023, plus 1,303,882 shares of our Common Stock issued from the exercise of the Existing Warrants pursuant to the Inducement Letter Agreement, and excludes as of such date:


	·	127 shares of Common Stock issuable upon the exercise of stock options outstanding as of September 30, 2023, having a weighted average exercise price of $16,445.06 per share;

	·	69,255 shares of Common Stock issuable upon the vesting of restricted stock units outstanding as of September 30, 2023;

	·	1,220,728 shares of Common Stock issuable upon the exercise of warrants (exclusive of the Existing Warrants) outstanding as of September 30, 2023, having a weighted average exercise price of $18.12 per share;

	·	826,370 Abeyance Shares issuable pursuant to certain Existing Warrants and upon receipt of a notice from any applicable Warrant Holder that such Abeyance Shares may be issued in compliance with the beneficial ownership limitations contained in the applicable Warrant Holder’s Existing Warrants;

	·	127,293 shares of Common Stock reserved for future issuance under our 2020 Long-Term Incentive Plan as of September 30, 2023; and

	·	660 shares of Common Stock reserved for future issuance under our Employee Stock Purchase Plan as of September 30, 2023.

RISK FACTORS

Investing in our securities involves a high degree of risk. Before investing in our securities, you should carefully consider the risks, uncertainties and assumptions contained in this prospectus and discussed under the heading “Risk Factors” included in our Annual Report on Form 10-K for the year ended December 31, 2022, as revised or supplemented by subsequent filings, which are on file with the SEC and are incorporated herein by reference, and which may be amended, supplemented or superseded from time to time by other reports we file with the SEC in the future. The risks described in these documents are not the only ones we face, but those that we consider to be material. There may be other unknown or unpredictable economic, business, competitive, regulatory or other factors that could have material adverse effects on our future results. Our business, financial condition, results of operations and future growth prospects could be materially and adversely affected by any of these risks. In these circumstances, the market price of our Common Stock could decline, and you may lose all or part of your investment.

Use of Proceeds

We will not receive any of the proceeds from the sale of the Common Stock by the Selling Stockholders. The shares offered hereby are issuable upon the exercise of the Warrants. Upon exercise of the Warrants for cash, we will receive the applicable cash exercise price paid by the holders of the Warrants of approximately $4.9 million (assuming the full exercise of the Warrants).

We intend to use any proceeds received by us from the cash exercise of the Warrants to fund the development of our product candidates, other research and development activities and for general working capital needs. We may also use a portion of any proceeds received by us from the cash exercise of the Warrants to acquire or invest in complementary businesses, products and technologies or to fund the development of any such complementary businesses, products or technologies. We currently have no plans for any such acquisitions.

DIVIDEND POLICY

We have never paid any cash dividends and do not anticipate paying any cash dividends on our Common Stock in the foreseeable future. We expect to retain future earnings, if any, for use in our development activities and the operation of our business. The payment of any future dividends will be subject to the discretion of our Board of Directors and will depend, among other things, upon our results of operations, financial condition, cash requirements, prospects and other factors that our Board of Directors may deem relevant.

DETERMINATION OF OFFERING PRICE

The prices at which the shares of Common Stock covered by this prospectus may actually be sold will be determined by the prevailing public market price for shares of our Common Stock or by negotiations between the Selling Stockholders and buyers of our Common Stock in private transactions or as otherwise described in “Plan of Distribution.”

SELLING STOCKHOLDERS

The Common Stock being offered by the Selling Stockholders consists of shares of Common Stock issuable to the Selling Stockholders upon exercise of the Warrants. For additional information regarding the issuances of the Warrants, see “December 2023 Offering” in the Prospectus Summary section above. We are registering the shares of Common Stock in order to permit the Selling Stockholders to offer the shares for resale from time to time. Except for (a) the ownership of the Warrants and (b) with respect to the Warrants issued as compensation to the Placement Agent, who has acted as our Placement Agent in a number of past offerings, or its designees, the Selling Stockholders have not had any material relationship with us within the past three years.

The table below lists the Selling Stockholders and other information regarding the beneficial ownership of the shares of Common Stock by each of the Selling Stockholders. The second column lists the number of shares of Common Stock beneficially owned by each Selling Stockholder, based on its ownership of the Warrants, as of December 8, 2023, assuming exercise of the Warrants held by the Selling Stockholders on that date, without regard to any limitations on exercises.

The third column lists the shares of Common Stock being offered under this prospectus by the Selling Stockholder.

In accordance with the terms of the Inducement Letter Agreement with the Selling Stockholders, this prospectus generally covers the resale of the maximum number of shares of Common Stock issuable upon exercise of the related Warrants issued in and in connection with the Inducement Letter Agreement, determined as if the outstanding Warrants were exercised in full as of the trading day immediately preceding the date this registration statement was initially filed with the SEC, each as of the trading day immediately preceding the applicable date of determination, without regard to any limitations on the exercise of the Warrants. The fourth column assumes the sale of all of the shares offered by the Selling Stockholders pursuant to this prospectus.

Under the terms of the Warrants, a Selling Stockholder may not exercise the Warrants to the extent such exercise would cause such Selling Stockholder, together with its affiliates and attribution parties, to beneficially own a number of shares of Common Stock which would exceed 4.99% or 9.99%, as applicable, of our then outstanding Common Stock following such exercise, excluding for purposes of such determination shares of Common Stock issuable upon exercise of such Warrants which have not been exercised. The number of shares in the second and fourth columns do not reflect this limitation. The Selling Stockholder may sell all, some or none of their shares in this offering. See “Plan of Distribution” below for further information.

						Shares Beneficially Owned After this Offering
Selling Stockholder	Number of Shares Beneficially Owned Before this Offering⁽¹⁾			Number of Shares to be Sold in this Offering		Number of Shares		Percentage of Total Outstanding Common Stock⁽¹⁾
Anson Investments Master Fund LP⁽²⁾		1,878,537	⁽³⁾		1,246,108		632,429		7.73%
Armistice Capital Master Fund Ltd. ⁽⁴⁾		898,146			598,764		299,382		3.67%
Intracoastal Capital, LLC⁽⁵⁾		1,177,723			540,000		637,723		7.24%
Sabby Volatility Warrant Master Fund, Ltd. ⁽⁶⁾		2,581,641	⁽⁷⁾		1,875,632		706,009		8.64%
Noam Rubinstein⁽⁸⁾		102,231			50,327		51,904		*
Craig Schwabe⁽⁸⁾		10,556			5,392		5,164		*
Michael Vasinkevich⁽⁸⁾		201,248			102,452		98,796		1.20%
Charles Worthman⁽⁸⁾		3,248			1,598		1,650		*

* Represents beneficial ownership of less than one percent.

(1) The ability to exercise the Warrants held by the Selling Stockholders is subject to a beneficial ownership limitation that, at the time of initial issuance of the Warrants, was capped at either 4.99% or 9.99% beneficial ownership of the Company’s issued and outstanding Common Stock (post-exercise). These beneficial ownership limitations may be adjusted up or down, subject to providing advanced notice to the Company. Beneficial ownership as reflected in the selling stockholder table reflects the total number of shares potentially issuable underlying the Warrants and does not give effect to these beneficial ownership limitations. Accordingly, actual beneficial ownership, as calculated in accordance with Section 13(d) and Rule 13d-3 thereunder may be lower than as reflected in the table.

(2) Anson Advisors Inc. and Anson Funds Management LP, the Co-Investment Advisers of Anson Investments Master Fund LP (“Anson”), hold voting and dispositive power over the Common Stock held by Anson. Bruce Winson is the managing member of Anson Management GP LLC, which is the general partner of Anson Funds Management LP. Moez Kassam and Amin Nathoo are directors of Anson Advisors Inc. Mr. Winson, Mr. Kassam and Mr. Nathoo each disclaim beneficial ownership of these shares of Common Stock except to the extent of their pecuniary interest therein. The principal business address of Anson is Maples Corporate Services Limited, PO Box 309, Ugland House, Grand Cayman, KY1-1104, Cayman Islands.

(3) Inclusive of 293,054 Abeyance Shares issuable to Anson pursuant to certain Existing Warrants held by Anson upon notice received from Anson that such Abeyance Shares may be issued in compliance with the beneficial ownership limitations contained in the Existing Warrants held by Anson.

(4) The shares are directly held by Armistice Capital Master Fund Ltd., a Cayman Islands exempted company (the "Master Fund"), and may be deemed to be indirectly beneficially owned by: (i) Armistice Capital, LLC ("Armistice Capital"), as the investment manager of the Master Fund; and (ii) Steven Boyd, as the Managing Member of Armistice Capital. Armistice Capital and Steven Boyd disclaim beneficial ownership of the securities except to the extent of their respective pecuniary interests therein.

(5) Mitchell P. Kopin (“Mr. Kopin”) and Daniel B. Asher (“Mr. Asher”), each of whom are managers of Intracoastal Capital LLC (“Intracoastal”), have shared voting control and investment discretion over the securities reported herein that are held by Intracoastal. As a result, each of Mr. Kopin and Mr. Asher may be deemed to have beneficial ownership (as determined under Section 13(d) of the Securities and Exchange Act of 1934, as amended (the “Exchange Act”)) of the securities reported herein that are held by Intracoastal.

(6) Sabby Management, LLC, the investment manager to Sabby Volatility Warrant Master Fund, Ltd. (“Sabby”), has discretionary authority to vote and dispose of the shares held by Sabby and may be deemed to be the beneficial owner of these shares. Hal Mintz (“Mr. Mintz”), in his capacity as manager of Sabby Management, LLC, may also be deemed to have investment discretion and voting power over the shares held by Sabby. Sabby Management, LLC and Mr. Mintz each disclaim any beneficial ownership of these shares.

(7) Inclusive of 533,316 Abeyance Shares issuable to Sabby pursuant to certain Existing Warrants held by Sabby upon notice received from Sabby that such Abeyance Shares may be issued in compliance with the beneficial ownership limitations contained in the Existing Warrants held by Sabby.

(8) Each of the Selling Stockholders is affiliated with Wainwright, a registered broker dealer with a registered address of H.C. Wainwright & Co., LLC, 430 Park Ave, 3rd Floor, New York, NY 10022, and has sole voting and dispositive power over the securities held. The number of shares beneficially owned prior to this offering consist of shares of common stock issuable upon exercise of placement agent warrants, which were received as compensation. The Selling Stockholder acquired the placement agent warrants in the ordinary course of business and, at the time the placement agent warrants were acquired, the Selling Stockholder had no agreement or understanding, directly or indirectly, with any person to distribute such securities.

PLAN OF DISTRIBUTION

Each Selling Stockholder of the securities and any of their pledgees, assignees and successors-in-interest may, from time to time, sell any or all of their securities covered hereby on the principal trading market or any other stock exchange, market or trading facility on which the securities are traded or in private transactions. These sales may be at fixed or negotiated prices. A Selling Stockholder may use any one or more of the following methods when selling securities:

	·	ordinary brokerage transactions and transactions in which the broker dealer solicits purchasers;
	·	block trades in which the broker-dealer will attempt to sell the securities as agent but may position and resell a portion of the block as principal to facilitate the transaction;
	·	purchases by a broker-dealer as principal and resale by the broker dealer for its account;
	·	an exchange distribution in accordance with the rules of the applicable exchange;
	·	privately negotiated transactions;
	·	settlement of short sales;
	·	in transactions through broker-dealers that agree with the Selling Stockholders to sell a specified number of such securities at a stipulated price per security;
	·	through the writing or settlement of options or other hedging transactions, whether through an options exchange or otherwise;
	·	a combination of any such methods of sale; or
	·	any other method permitted pursuant to applicable law.

The Selling Stockholders may also sell securities under Rule 144 or any other exemption from registration under the Securities Act of 1933, as amended (the “Securities Act”), if available, rather than under this prospectus.

Broker-dealers engaged by the Selling Stockholders may arrange for other brokers-dealers to participate in sales. Broker-dealers may receive commissions or discounts from the Selling Stockholders (or, if any broker-dealer acts as agent for the purchaser of securities, from the purchaser) in amounts to be negotiated, but, except as set forth in a supplement to this prospectus, in the case of an agency transaction not in excess of a customary brokerage commission in compliance with FINRA Rule 2121; and in the case of a principal transaction a markup or markdown in compliance with FINRA Rule 2121.

In connection with the sale of the securities or interests therein, the Selling Stockholders may enter into hedging transactions with broker-dealers or other financial institutions, which may in turn engage in short sales of the securities in the course of hedging the positions they assume. The Selling Stockholders may also sell securities short and deliver these securities to close out their short positions, or loan or pledge the securities to broker-dealers that in turn may sell these securities. The Selling Stockholders may also enter into option or other transactions with broker-dealers or other financial institutions or create one or more derivative securities which require the delivery to such broker-dealer or other financial institution of securities offered by this prospectus, which securities such broker-dealer or other financial institution may resell pursuant to this prospectus (as supplemented or amended to reflect such transaction).

The Selling Stockholders and any broker-dealers or agents that are involved in selling the securities may be deemed to be “underwriters” within the meaning of the Securities Act in connection with such sales. In such event, any commissions received by such broker-dealers or agents and any profit on the resale of the securities purchased by them may be deemed to be underwriting commissions or discounts under the Securities Act. Each Selling Stockholder has informed us that it does not have any written or oral agreement or understanding, directly or indirectly, with any person to distribute the securities.

We are required to pay certain fees and expenses incurred incident to the registration of the securities.

We have agreed to keep this prospectus effective until the earlier of (i) the date on which the securities may be resold by the Selling Stockholders without registration and without regard to any volume or manner-of-sale limitations by reason of Rule 144, without the requirement for us to be in compliance with the current public information under Rule 144 under the Securities Act or any other rule of similar effect or (ii) all of the securities have been sold pursuant to this prospectus or Rule 144 under the Securities Act or any other rule of similar effect. The resale securities will be sold only through registered or licensed brokers or dealers if required under applicable state securities laws. In addition, in certain states, the resale securities covered hereby may not be sold unless they have been registered or qualified for sale in the applicable state or an exemption from the registration or qualification requirement is available and is complied with.

Under applicable rules and regulations under the Exchange Act, any person engaged in the distribution of the resale securities may not simultaneously engage in market making activities with respect to the Common Stock for the applicable restricted period, as defined in Regulation M, prior to the commencement of the distribution. In addition, the Selling Stockholders will be subject to applicable provisions of the Exchange Act and the rules and regulations thereunder, including Regulation M, which may limit the timing of purchases and sales of the Common Stock by the Selling Stockholders or any other person. We will make copies of this prospectus available to the Selling Stockholders and have informed them of the need to deliver a copy of this prospectus to each purchaser at or prior to the time of the sale (including by compliance with Rule 172 under the Securities Act).

DESCRIPTION OF SECURITIES TO BE REGISTERED

The following summary description of our capital stock is based on the provisions of our amended and restated certificate of incorporation and amended and restated bylaws and the applicable provisions of the Delaware General Corporation Law (“DGCL”). This information is qualified entirely by reference to the applicable provisions of our amended and restated certificate of incorporation, amended and restated bylaws and the DGCL. For information on how to obtain copies of our amended and restated certificate of incorporation and amended and restated bylaws, which are exhibits to the registration statement of which this prospectus forms a part, see the sections titled “Where You Can Find More Information” and “Incorporation of Certain Information by Reference” in this prospectus.

General

Our authorized capital stock consists of 100,000,000 shares of Common Stock, par value $0.0001 per share and 10,000,000 shares of preferred stock, par value $0.0001 per share.

Common Stock

Holders of our Common Stock are entitled to one vote per share for the election of members of our Board of Directors and on all other matters that require stockholder approval. Holders of our Common Stock may not cumulate votes for the election of directors. Subject to any preferential rights of any outstanding preferred stock, in the event of our liquidation, dissolution or winding up, holders of our Common Stock are entitled to share ratably in the assets remaining after payment of liabilities and the liquidation preferences of any outstanding preferred stock. Holders of Common Stock have the right to receive dividends when, as and if, declared by the Board of Directors. Our Common Stock does not carry any preemptive rights enabling a holder to subscribe for, or receive shares of, any class of our Common Stock or any other securities convertible into shares of any class of our Common Stock. There are no redemption or sinking-fund provisions applicable to our Common Stock.

Preferred Stock

The shares of preferred stock have such rights and preferences as our Board of Directors shall determine, from time to time, the Board of Directors may divide the preferred stock into any number of series and shall fix the designation and number of shares of each such series. Our Board of Directors may determine and alter the rights, powers, preferences and privileges, and qualifications, restrictions and limitations thereof, including, but not limited to, voting rights (if any), granted to and imposed upon any wholly unissued series of preferred stock. Our Board of Directors (within the limits and restrictions of any resolutions adopted originally fixing the number of shares of any series) may increase or decrease the number of shares of that series; provided, that no such decrease shall reduce the number of shares of such series to a number less than the number of shares of such series then outstanding, plus the number of shares reserved for issuance upon the exercise of outstanding options, rights or warrants or upon the conversion of any outstanding securities issued by us convertible into shares of such series.

Our Common Stock is subject to the express terms of our preferred stock and any series thereof. Our Board of Directors may issue preferred stock with voting, dividend, liquidation and other rights that could adversely affect the relative rights of the holders of our Common Stock.

Anti-Takeover Effects of Provisions of our Certificate of Incorporation and Bylaws

Certificate of Incorporation and Bylaw Provisions. Certain provisions of our amended and restated certificate of incorporation and amended and restated bylaws, which provisions are summarized in the following paragraphs, may have an anti-takeover effect and may delay, defer or prevent a takeover attempt that a stockholder might consider in its best interest, including those attempts that might result in a premium over the market price for the shares held by stockholders.

Filling Vacancies. Any vacancy on our Board of Directors, however occurring, including a vacancy resulting from an increase in the size of the Board of Directors, may only be filled by the affirmative vote of a majority of our directors then in office even if less than a quorum.

No Written Consent of Stockholders. Our amended and restated certificate of incorporation provides that all stockholder actions are required to be taken by a vote of the stockholders at an annual or special meeting, and that stockholders may not take any action by written consent in lieu of a meeting.

Advance Notice Requirements. Our amended and restated bylaws include advance notice procedures with regard to stockholder proposals relating to the nomination of candidates for election as directors or new business to be brought before meetings of our stockholders. These procedures provide that notice of stockholder proposals must be timely given in writing to our corporate secretary prior to the meeting at which the action is to be taken. Generally, to be timely, notice must be received at our principal executive offices not less than 90 days nor more than 120 days prior to the first anniversary date of the annual meeting for the preceding year. The notice must contain certain information specified in the amended and restated bylaws.

Amendment to Bylaws and Certificate of Incorporation. As required by the DGCL any amendment to our amended and restated certificate of incorporation must first be approved by a majority of our Board of Directors and, if required by law or our amended and restated certificate of incorporation, thereafter be approved by a majority of the outstanding shares entitled to vote on the amendment, and a majority of the outstanding shares of each class entitled to vote thereon as a class. Our amended and restated bylaws may be amended by the affirmative vote of a majority vote of the directors then in office, subject to any limitations set forth in the amended and restated bylaws.

Blank Check Preferred Stock. Our amended and restated certificate of incorporation provides for 10,000,000 authorized shares of preferred stock. The existence of authorized but unissued shares of preferred stock may enable our Board of Directors to render more difficult or to discourage an attempt to obtain control of us by means of a merger, tender offer, proxy contest, or otherwise. In this regard, the amended and restated certificate of incorporation grants the Board of Directors broad power to establish the rights and preferences of authorized and unissued shares of preferred stock. The issuance of shares of preferred stock could decrease the amount of earnings and assets available for distribution to holders of shares of Common Stock. The issuance may also adversely affect the relative rights and powers, including voting rights, of these holders and may have the effect of delaying, deterring, or preventing a change of control of the Company.

Exclusive Forum Provision in Certificate of Incorporation. Our amended and restated certificate of incorporation provides that the Court of Chancery of the State of Delaware is the exclusive forum for the following types of actions or proceedings: any derivative action or proceeding brought on behalf of the Company, any action asserting a claim of breach of a fiduciary duty owed by any director, officer or other employee of the Company to the Company or the Company’s stockholders, any action asserting a claim against the Company arising pursuant to any provision of the DGCL or our amended and restated certificate of incorporation or our amended and restated bylaws, or any action asserting a claim against us governed by the internal affairs doctrine. Despite the fact that our amended and restated certificate of incorporation provides for this exclusive forum provision to be applicable to the fullest extent permitted by applicable law, Section 27 of the Exchange Act, creates exclusive federal jurisdiction over all suits brought to enforce any duty or liability created by the Exchange Act or the rules and regulations thereunder and Section 22 of the Securities Act, creates concurrent jurisdiction for federal and state courts over all suits brought to enforce any duty or liability created by the Securities Act or the rules and regulations thereunder. As a result, this provision of our amended and restated certificate of incorporation would not apply to claims brought to enforce a duty or liability created by the Securities Act, Exchange Act, or any other claim for which the federal courts have exclusive jurisdiction.

LEGAL MATTERS

Certain legal matters relating to the issuance of the securities offered hereby will be passed upon for us by Hogan Lovells US LLP.

EXPERTS

The consolidated financial statements as of December 31, 2022 and 2021 and for each of the two years in the period ended December 31, 2022 incorporated by reference in this prospectus and in the registration statement have been so incorporated in reliance on the report of BDO USA, LLP (n/k/a BDO USA, P.C.), an independent registered public accounting firm, incorporated herein by reference, given on the authority of said firm as experts in auditing and accounting. The report on the consolidated financial statements contains an explanatory paragraph regarding the Company’s ability to continue as a going concern.

Where You Can Find More Information

We are required to file annual, quarterly and current reports, proxy statements and other information with the SEC. Our filings with the SEC are available to the public at the SEC’s Internet web site at http://www.sec.gov. Copies of certain information filed by us with the SEC are also available on our website at www.phiopharma.com. Our website is not a part of this prospectus and is not incorporated by reference in this prospectus, and you should not consider the contents of our website in making an investment decision with respect to our Common Stock.

We have filed a registration statement, of which this prospectus is a part, covering the securities offered hereby. As allowed by SEC rules, this prospectus does not include all of the information contained in the registration statement and the included exhibits, financial statements and schedules. You are referred to the registration statement, the included exhibits, financial statements and schedules for further information. You should review the information and exhibits in the registration statement for further information about us and our subsidiaries and the securities we are offering. Statements in this prospectus concerning any document we filed as an exhibit to the registration statement or that we otherwise filed with the SEC are not intended to be comprehensive and are qualified by reference to these filings. You should review the complete document to evaluate these statements.

INCORPORATION OF CERTAIN INFORMATION BY REFERENCE

The SEC allows us to “incorporate by reference” the information we have filed with them, which means that we can disclose important information to you by referring you to those documents. The information we incorporate by reference is an important part of this prospectus, and information that we file later with the SEC will automatically update and supersede this information. The documents we are incorporating by reference are:

	·	Our Annual Report on Form 10-K for the year ended December 31, 2022, filed with the SEC on March 22, 2023;

	·	Our Quarterly Reports on Form 10-Q for the quarters ended March 31, 2023, June 30, 2023 and September 30, 2023 filed with the SEC on May 11, 2023, August 10, 2023 and November 9, 2023;

	·	Our Current Reports on Form 8-K, filed with the SEC on January 6, 2023, January 25, 2023, February 13, 2023, February 22, 2023, March 10, 2023, April 17, 2023, April 18, 2023, April 20, 2023, April 20, 2023, May 16, 2023, May 24, 2023, June 2, 2023, July 26, 2023, August 21, 2023, November 9, 2023 and December 8, 2023; and

	·	The description of our Common Stock contained in our registration statement on Form 8-A12B filed with the SEC on February 7, 2014, as updated by the description of our Common Stock filed as Exhibit 4.13 to our Annual Report on Form 10-K for the year ended December 31, 2019, including any amendment or report filed for the purpose of updating such description.

All documents we file with the SEC pursuant to Sections 13(a), 13(c), 14 or 15(d) of the Exchange Act, except as to any portion of any report or document that is not deemed filed under such provisions, (1) on or after the date of filing of the registration statement containing this prospectus and prior to the effectiveness of the registration statement and (2) on or after the date of this prospectus until the earlier of the date on which all of the securities registered hereunder have been sold or the registration statement of which this prospectus forms a part has been withdrawn, shall be deemed incorporated by reference in this prospectus and to be a part of this prospectus from the date of filing of those documents and will be automatically updated and, to the extent described above, supersede information contained or incorporated by reference in this prospectus and previously filed documents that are incorporated by reference in this prospectus.

Nothing in this prospectus shall be deemed to incorporate information furnished but not filed with the SEC pursuant to Item 2.02, 7.01 or 9.01 of Form 8-K.

Upon written or oral request, we will provide without charge to each person, including any beneficial owner, to whom a copy of the prospectus is delivered a copy of any or all of the reports or documents incorporated by reference herein (other than exhibits to such documents, unless such exhibits are specifically incorporated by reference herein). You may request a copy of these filings, at no cost, by writing or telephoning us at the following address: Phio Pharmaceuticals Corp., 257 Simarano Drive, Suite 101, Marlborough, Massachusetts 01752 Attention: Investor Relations, telephone: (508) 767-3861. We maintain a website at www.phiopharma.com. You may access our definitive proxy statements on Schedule 14A, annual reports on Form 10-K, quarterly reports on Form 10-Q, current reports on Form 8-K and periodic amendments to those reports filed or furnished pursuant to Section 13(a) or 15(d) of the Exchange Act with the SEC free of charge at our website as soon as reasonably practicable after such material is electronically filed with, or furnished to, the SEC. The information contained in, or that can be accessed through, our website is not incorporated by reference in, and is not part of, this prospectus. We have not authorized anyone to provide you with any information that differs from that contained in this prospectus. Accordingly, you should not rely on any information that is not contained in this prospectus. You should not assume that the information in this prospectus is accurate as of any date other than the date of the front cover of this prospectus.