# EDGAR Filing Document

**Accession Number:** 0001574235
**File Stem:** 0001493152-26-018202
**Filing Date:** 2026-4
**Character Count:** 14809
**Document Hash:** 849f049028048582538f4430b77d583a
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001493152-26-018202.hdr.sgml**: 20260421

**ACCESSION NUMBER**: 0001493152-26-018202

**CONFORMED SUBMISSION TYPE**: 8-K

**PUBLIC DOCUMENT COUNT**: 13

**CONFORMED PERIOD OF REPORT**: 20260416

**ITEM INFORMATION**: Regulation FD Disclosure

**ITEM INFORMATION**: Other Events

**ITEM INFORMATION**: Financial Statements and Exhibits

**FILED AS OF DATE**: 20260421

**DATE AS OF CHANGE**: 20260421

**FILER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** Pulmatrix, Inc.
- **CENTRAL INDEX KEY:** 0001574235
- **STANDARD INDUSTRIAL CLASSIFICATION:** PHARMACEUTICAL PREPARATIONS [2834]
- **ORGANIZATION NAME:** 03 Life Sciences
- **EIN:** 461821392
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** 8-K
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-36199
- **FILM NUMBER:** 26876769

**BUSINESS ADDRESS:**
- **STREET 1:** 945 CONCORD STREET
- **STREET 2:** SUITE 1217
- **CITY:** FRAMINGHAM
- **STATE:** MA
- **ZIP:** 01701
- **BUSINESS PHONE:** (888) 355-4440

**MAIL ADDRESS:**
- **STREET 1:** 945 CONCORD STREET
- **STREET 2:** SUITE 1217
- **CITY:** FRAMINGHAM
- **STATE:** MA
- **ZIP:** 01701

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** Ruthigen, Inc.
- **DATE OF NAME CHANGE:** 20130411

?xml version='1.0' encoding='ASCII'?

**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): April 16, 2026**

**PULMATRIX, INC.**

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

---

| | | |
|:---|:---|:---|
| **Delaware** | **001-36199** | **46-1821392** |
| **(State or other jurisdiction**<br> **of incorporation)** | **(Commission**<br> **File Number)** | **(IRS Employer**<br> **Identification No.)** |

---

**945 Concord Street, Suite 1217**

**Framingham, MA 01701**

**(Address of principal executive offices) (Zip Code)**

**(888) 355-4440**

**(Registrant's telephone number, including area code)**

**N/A**

**(Former name or former address, if changed since last report)**

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:

☐ 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 exchange on which registered** |
| **Common Stock, par value $0.0001 per share** | **PULM** | **The NASDAQ Stock Market LLC** |

---

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 7.01 Regulation FD Disclosure.**

On April 21, 2026, Pulmatrix, Inc. (the "***Company***") issued a press release announcing the closing of the Private Placement (as defined herein). A copy of the press release is furnished as Exhibit 99.1 hereto and is incorporated herein by reference.

The information in this Current Report on Form 8-K (including Exhibit 99.1 attached hereto) is being furnished pursuant to Item 7.01 and shall not be deemed to be filed for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the "***Exchange Act***"), or otherwise be subject to the liabilities of that section, nor shall it be deemed to be incorporated by reference in any filing under the Securities Act of 1933, as amended (the "***Securities Act***"), or the Exchange Act, whether made before or after the date hereof and regardless of any general incorporation language in such filing.

**Item 8.01 Other Events**

On April 16, 2026, the Company closed its previously announced private placement of its Series B Preferred Stock, par value $0.0001 per share (the "***Private Placement***"). The Private Placement was exempt from the registration requirements of the Securities Act pursuant to the exemption for transactions by an issuer not involving any public offering under Section 4(a)(2) of the Securities Act and Rule 506 of Regulation D of the Securities Act and in reliance on similar exemptions under applicable state laws.

**Item 9.01 Financial Statements and Exhibits.**

(d) Exhibits

---

| | |
|:---|:---|
| **Exhibit No.** | **Description** |
| 99.1 | [Press Release dated April 21, 2026 (furnished pursuant to Item 7.01)](ex99-1.htm) |
| 104 | Cover Page Interactive Data File (formatted as Inline XBRL) |

---

**SIGNATURES**

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

---

| | | |
|:---|:---|:---|
|  | **PULMATRIX, INC.** | **PULMATRIX, INC.** |
| Date: April 21, 2026 | By: | */s/ Peter Ludlum* |
|  |  | Peter Ludlum |
|  |  | Interim Chief Executive Officer and Interim Chief Financial Officer |

---

## Exhibit 99.1

**Exhibit 99.1**

![](ex99-1_001.jpg)

**Pulmatrix Announces Closing of Preferred Stock Transaction as Part of Planned Merger**

*Series B Preferred Stock investment made in Pulmatrix with a conversion price of $2.20 is a part of the ongoing merger process*

 

Framingham, Mass., April 21, 2026 – Pulmatrix, Inc. ("Pulmatrix" or the "Company") (Nasdaq: PULM), today announced the closing of its previously announced private placement of Series B Convertible Preferred Stock ("Series B Preferred Stock") with an affiliate of Eos SENOLYTIX, Inc. ("Eos"), which such transaction is a part of its planned merger with Eos. The Series B Preferred Stock is convertible into common stock at a price per share of $2.20.

The aggregate gross proceeds to the Company from the offering were approximately $1 million, before deducting offering expenses payable by the Company. The Company currently intends to use the permitted net proceeds from the offering for working capital and other general corporate purposes.

Peter Ludlum, Interim Chief Executive Officer of Pulmatrix, commented, "We have taken an important initial step forward as part of the planned merger and are pleased that investors supporting Eos chose to make this investment in Pulmatrix as part of the signing of the definitive merger agreement."

The Series B Preferred Stock was issued in a private placement under Section 4(a)(2) of the Securities Act of 1933, as amended (the "Securities Act"), and Regulation D promulgated thereunder and, along with the shares of common stock underlying the Series B Preferred Stock, have not been registered under the Securities Act, or applicable state securities laws. Accordingly, the Series B Preferred Stock and underlying shares of common stock may not be offered or sold in the United States except pursuant to an effective registration statement or an applicable exemption from the registration requirements of the Securities Act and such applicable state securities laws.

This press release shall not constitute an offer to sell or the solicitation of an offer to buy any of the securities described herein, nor shall there be any sale of these securities in any state or jurisdiction in which such offer, solicitation or sale would be unlawful prior to the registration or qualification under the securities laws of any such state or jurisdiction.

***Series B Preferred Stock***

 ****

The Series B Preferred Stock is convertible into shares of Pulmatrix common stock as elected by the holders of the Series B Preferred Stock and may be exercised at any time at a conversion price of $2.20 per share (the "Conversion Price") from and after a date that is 90 days following the initial date of issuance. The Conversion Price is subject to customary adjustments for stock dividends, stock splits, reclassifications, stock combinations and the like (subject to certain exceptions). The holders of the Series B Preferred Stock are entitled to vote together with the holders of common stock as a single class, in the same manner and with the same effect as the holders of common stock.

The complete terms of the Series B Preferred Stock are as set forth in the form of Certificate of Designation of Preferences, Rights and Limitations of Series B Convertible Preferred Stock (the "Certificate of Designations"), which such Certificate of Designations was filed with the Secretary of State for the State of Delaware on March 26, 2026, prior to the closing of the private placement.

![](ex99-1_001.jpg)

**About Pulmatrix, Inc.**

Pulmatrix is a biopharmaceutical company that has focused on the development of novel inhaled therapeutic products intended to prevent and treat migraine and respiratory diseases with important unmet medical needs using its patented iSPERSE™ technology. The Company's proprietary product pipeline includes treatments for central nervous system ("CNS") disorders such as acute migraine and serious lung diseases such as Chronic Obstructive Pulmonary Disease ("COPD") and allergic bronchopulmonary aspergillosis ("ABPA"). Pulmatrix's product candidates are based on its proprietary engineered dry powder delivery platform, iSPERSE™, which seeks to improve therapeutic delivery to the lungs by optimizing pharmacokinetics and reducing systemic side effects to improve patient outcomes. For more on the Company's inhaled product candidates please visit:

<u>https://www.pulmatrix.com/pipeline.html.</u>

**About Eos SENOLYTIX, Inc.**

Eos SENOLYTIX is a biotechnology company focused on developing first-in-class gerotherapeutic peptide medicines that target the underlying biological mechanisms of aging. Eos's lead clinical candidates, PTC-2105 and PTC-2107, both proprietary MitoXcel™ geropeptides, have demonstrated the ability to rejuvenate naturally aged mice via two separate mechanisms, both via a single, aging-specific target, the mitochondrial membrane potential (MMP), also called the "Δψm". These two mechanisms include (1) the return of the efficiency of mitochondrial function in aging cells almost immediately back to their younger, more efficient phenotype, and (2) the profound elimination of senescent cells throughout every organ in the body, including the brain, reducing their negative systemic inflammatory effects. Extensive preclinical studies suggest the MitoXcel™ platform may be a broad gerotherapeutic that improves body composition, increasing lean muscle mass, and enhancing physical function in aging animals. By targeting fundamental processes driving aging and aging-related diseases, Eos SENOLYTIX is pursuing a unique therapeutic opportunity to intervene in the aging process in ways that were once thought impossible. Eos SENOLYTIX is headquartered in Houston, Texas and operates within the broader SENOTHERAPEUTIX / GEROTHERAPEUTIX group of longevity companies, which focuses on developing therapeutics targeting fundamental drivers of aging to improve healthspan and lifespan. For more information, visit <u>https://www.eossenolytix.com</u>.

**Forward-Looking Statements**

*Certain statements in this press release that are forward-looking and not statements of historical fact are forward-looking statements within the meaning of the federal securities laws. Such forward-looking statements include, but are not limited to, statements of historical fact and may be identified by words such as "anticipates," "assumes," "believes," "can," "could," "estimates," "expects," "forecasts," "guides," "intends," "is confident that," "may," "plans," "seeks," "projects," "targets," and "would," and their opposites and similar expressions are intended to identify forward-looking statements. Such forward-looking statements are based on the beliefs of management as well as assumptions made by and information currently available to management and include, but are not limited to, the use of proceeds from the private placement and conversion of the Series B Preferred Stock. Actual results could differ materially from those contemplated by the forward-looking statements as a result of certain factors, including, but not limited to, the consummation of any other potential reverse merger transaction in the future, among others; the Company's ability to divest its clinical assets on terms favorable to the Company, or at all, the Company's ability to maintain compliance with the listing standards of the Nasdaq Capital Market; the Company's ability to conduct its business and raise capital in the future when needed; delays in planned clinical trials; the ability to establish that potential products are efficacious or safe in preclinical or clinical trials; the ability to establish or maintain collaborations on the development of therapeutic candidates; the ability to obtain appropriate or necessary governmental approvals to market potential products; the ability to obtain future funding for developmental products and working capital and to obtain such funding on commercially reasonable terms; the Company's ability to manufacture product candidates on a commercial scale or in collaborations with third parties; changes in the size and nature of competitors; the ability to retain key executives and scientists; the ability to secure and enforce legal rights related to the Company's products, including patent protection. A discussion of these and other factors, including risks and uncertainties with respect to the Company, including the proposed Merger with Cullgen, is set forth in the Company's filings with the Securities and Exchange Commission, including its most recent Annual Report on Form 10-K, as may be supplemented or amended by the Company's Quarterly Reports on Form 10-Q and Current Reports on Form 8-K. The Company disclaims any intention or obligation to revise any forward-looking statements, whether as a result of new information, future events or otherwise, except as required by law.*

 

**Investor Contact:**

Chuck Padala

Managing Director

LifeSci Advisors

646-627-8390

<u>chuck@lifesciadvisors.com</u>