# EDGAR Filing Document

**Accession Number:** 0001533040
**File Stem:** 0001683168-25-005392
**Filing Date:** 2025-7
**Character Count:** 16223
**Document Hash:** 07a0e79d8d72f59b50c79fd56e8e5ccd
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001683168-25-005392.hdr.sgml**: 20250725

**ACCESSION NUMBER**: 0001683168-25-005392

**CONFORMED SUBMISSION TYPE**: 8-K

**PUBLIC DOCUMENT COUNT**: 16

**CONFORMED PERIOD OF REPORT**: 20250725

**ITEM INFORMATION**: Other Events

**ITEM INFORMATION**: Financial Statements and Exhibits

**FILED AS OF DATE**: 20250725

**DATE AS OF CHANGE**: 20250725

**FILER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** Phio Pharmaceuticals Corp.
- **CENTRAL INDEX KEY:** 0001533040
- **STANDARD INDUSTRIAL CLASSIFICATION:** PHARMACEUTICAL PREPARATIONS [2834]
- **ORGANIZATION NAME:** 03 Life Sciences
- **EIN:** 453215903
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** 8-K
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-36304
- **FILM NUMBER:** 251150979

**BUSINESS ADDRESS:**
- **STREET 1:** 411 SWEDELAND ROAD
- **STREET 2:** SUITE 23-1080
- **CITY:** KING OF PRUSSIA
- **STATE:** PA
- **ZIP:** 19406
- **BUSINESS PHONE:** (508) 767-3861

**MAIL ADDRESS:**
- **STREET 1:** 411 SWEDELAND ROAD
- **STREET 2:** SUITE 23-1080
- **CITY:** KING OF PRUSSIA
- **STATE:** PA
- **ZIP:** 19406

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** RXi Pharmaceuticals Corp
- **DATE OF NAME CHANGE:** 20111019

?xml version='1.0' encoding='ASCII'? 8-K

**UNITED STATES**

**SECURITIES AND EXCHANGE COMMISSION**

**WASHINGTON, D.C. 20549**

**FORM 8-K**

**CURRENT REPORT**

**Pursuant to Section 13 or 15(d)**

**of the Securities Exchange Act of 1934**

**Date of report (Date of earliest event reported): July 25, 2025**

**PHIO PHARMACEUTICALS CORP.**

**(Exact name of registrant as specified in its charter)**

---

| | | |
|:---|:---|:---|
| **Delaware** | **001-36304** | **45-3215903** |
| (State or other jurisdiction of incorporation)  | (Commission File Number) | (I.R.S. Employer Identification No.) |

---

---

| | |
|:---|:---|
| **411 Swedeland Road, Suite 23-1080** |  |
| **King of Prussia, PA** | **19406** |
| (Address of principal executive offices) | (Zip Code) |

---

Registrant's telephone number, including area code: **(508) 767-3861**

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions (see General Instruction A.2. below):

☐ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425) 

☐ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12) 

☐ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b)) 

☐ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act:

---

| | | |
|:---|:---|:---|
| Title of each class: | Trading Symbol(s): | Name of each exchange on which registered: |
| **Common Stock, par value $0.0001 per share** | **PHIO** | **The Nasdaq** **Capital Market** |

---

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).

Emerging growth company ☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

**Item 8.01. Other Events.**

On July 25, 2025, Phio Pharmaceuticals Corp. ("Phio") issued press releases announcing (i) that it has entered into a comprehensive drug substance development services agreement with a U.S. manufacturing source for drug substance and (ii) pathology results for four of five patients in the fourth cohort in Phio's ongoing Phase 1b dose escalation clinical trial (NCT 06014086) designed to evaluate the safety and tolerability of neoadjuvant use of INTASYL PH-762.

The full text of the press releases are attached hereto as Exhibits 99.1 and 99.2 and incorporated herein by reference.

**Item 9.01. Financial Statements and Exhibits.**

(d) Exhibits.

---

| | |
|:---|:---|
| **Number** | **Description** |
| 99.1 | [Press Release, dated July 25, 2025](phio_ex9901.htm) |
| 99.2 | [Press Release, dated July 25, 2025](phio_ex9902.htm) |
| 104 | Cover Page Interactive Data File (embedded within the Inline XBRL document) |

---

**SIGNATURES**

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

---

| | | |
|:---|:---|:---|
| Date: July 25, 2025 | **PHIO PHARMACEUTICALS CORP.** | **PHIO PHARMACEUTICALS CORP.** |
|  | By: | /s/ Robert J. Bitterman |
|  | Name:<br> Title: | Robert J. Bitterman<br> President & Chief Executive Officer |

---

## Exhibit 99.1

**Exhibit 99.1**

![](image_001.jpg)

Phio Pharmaceuticals Announces Agreement with U.S. Manufacturing Source for Drug Substance

*-Agreement covers contract development and manufacturing of lead compound PH-762*

 

King of Prussia, Pennsylvania-(Newsfile Corp.-July 25, 2025) — Phio Pharmaceuticals Corp. (Nasdaq: PHIO) is a clinical-stage siRNA biopharmaceutical company developing therapeutics using its proprietary INTASYL® gene silencing technology to eliminate cancer. Phio announced today it has entered into a comprehensive drug substance development services agreement with a U.S. manufacturer. The company will analytical and process development and cGMP manufacture of Phio's lead development compound PH-762. This represents a critical next step in advancing Phio's intratumoral program to treat cutaneous carcinomas. Phio is currently enrolling patients for the 5th and expected final cohort in its Phase 1b dose escalation study for cutaneous squamous cell carcinoma, Merkel cell carcinoma and melanoma.

"We are delighted to be partnering with an organization known for its quality and expertise in oligonucleotide chemistry sequencing." said Mr. Bitterman, Phio's President and CEO. "Additionally, we value the strategic advantages to our management team of working with a U.S. based organization."

**About Phio Pharmaceuticals Corp.**

Phio Pharmaceuticals Corp. (Nasdaq: PHIO) is a clinical-stage siRNA biopharmaceutical company advancing its INTASYL<sup>®</sup> gene silencing technology focused on immuno-oncology therapeutics. Phio's INTASYL compounds are designed to enhance the body's immune cells to more effectively kill cancer cells. Phio's lead clinical program is an INTASYL compound, PH-762, that silences the PD-1 gene implicated in various forms of skin cancer. The on-going Phase 1b trial (NCT# 06014086) is evaluating PH-762 for the treatment of cutaneous squamous cell carcinoma, melanoma and Merkel cell carcinoma. PH-762 is a potential non-surgical treatment for skin cancers.

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. Examples of forward-looking statements contained in this press release include, among others, the possibility that our INTASYL® siRNA gene silencing technology will make the body's immune cells more effective in killing cancer cells and statements regarding our commercial and clinical strategy, development plans and timelines and other future events.*

*These statements are based only on our current beliefs, expectations and assumptions and 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 inflationary pressures, rising interest rates, recession fears, 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.

Jennifer Phillips: jphillips@phiopharma.com

Corporate Affairs

## Exhibit 99.2

**Exhibit 99.2**

![](image_002.jpg)

**Phio Pharmaceuticals Announces Pathology Results for Four of Five Patients in Fourth Cohort**

***Complete Pathologic Response in patient with cutaneous squamous cell carcinoma***

 ****

***Partial Response in Stage 4 metastatic Merkel cell patient***

King of Prussia — (Newsfile Corp.-July 25, 2025) -Phio Pharmaceuticals Corp. (Nasdaq: PHIO) is a clinical-stage siRNA biopharmaceutical company developing therapeutics using its proprietary INTASYL<sup>®</sup> gene silencing technology to eliminate cancer.

Phio announced today that pathologic results are available for four of the five patients treated in the fourth cohort. A complete pathologic response (100% tumor clearance) has been reported for one patient with cutaneous squamous cell carcinoma (cSCC). One patient with metastatic Merkel cell carcinoma was reported as a partial response (> 50% clearance). Two patients with cSCC were reported as having a pathologic non-response (<50% tumor clearance). Pathologic results for the remaining patient with cSCC are still pending.

Phio's ongoing Phase 1b dose escalation clinical trial (NCT 06014086) is designed to evaluate the safety and tolerability of neoadjuvant use of intratumoral PH-762 in Stages 1, 2 and 4 cSCC, Stage 4 melanoma, and Stage 4 Merkel cell carcinoma. To date, a total of 15 patients with cutaneous carcinomas have been treated across the four cohorts. There were no dose-limiting toxicities or clinically relevant treatment-emergent adverse effects in the patients receiving intratumoral PH-762 in this trial. Moreover, PH-762 has been well tolerated in all enrolled patients in each escalating dose cohort. No patients exhibited clinical progression of disease.

The cumulative pathologic response in 13 patients with cSCC include five complete response (100% clearance), one patient with a near complete response (>90% clearance) and one with a partial response (>50% clearance) and six patients with a pathologic non-response (< 50% clearance).

The one Merkel cell carcinoma patient with stage 4 metastatic disease had a partial response (>50% clearance). The melanoma patient was a non-responder (<50% clearance).

Phio is now enrolling what is expected to be the 5<sup>th</sup> and final cohort in the Phase 1b study.

"The positive safety and efficacy outcomes through the fourth cohort continue to indicate that PH-762 may present a viable non-surgical alternative in this large and continually expanding skin cancer market," said Robert Bitterman, CEO and Chairman of Phio Pharmaceuticals.

**About Phio Pharmaceuticals Corp.**

Phio Pharmaceuticals Corp. (Nasdaq: PHIO) is a clinical-stage siRNA biopharmaceutical company advancing its INTASYL<sup>®</sup> gene silencing technology focused on immuno-oncology therapeutics. Phio's INTASYL compounds are designed to enhance the body's immune cells to more effectively kill cancer cells. Phio's lead clinical program is an INTASYL compound, PH-762, that silences the PD-1 gene implicated in various forms of skin cancer. The on-going Phase 1b trial (NCT# 06014086) is evaluating PH-762 for the treatment of cutaneous squamous cell carcinoma, melanoma and Merkel cell carcinoma. PH-762 is a potential non-surgical treatment for skin cancers.

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. Examples of forward-looking statements contained in this press release include, among others, the possibility that our INTASYL® siRNA gene silencing technology will make the body's immune cells more effective in killing cancer cells and statements regarding our commercial and clinical strategy, development plans and timelines and other future events.*

*These statements are based only on our current beliefs, expectations and assumptions and 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 inflationary pressures, rising interest rates, recession fears, 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.

Jennifer Phillips: jphillips@phiopharma.com

Corporate Affairs