Form 8-K

8-K — Pulmatrix, Inc.

Accession: 0001493152-26-018202

Filed: 2026-04-21

Period: 2026-04-16

CIK: 0001574235

SIC: 2834 (PHARMACEUTICAL PREPARATIONS)

Item: Regulation FD Disclosure

Item: Other Events

Item: Financial Statements and Exhibits

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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

incorporation)

(Commission

File

Number)

(IRS

Employer

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 ☐

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.

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

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)

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.

Date:

April 21, 2026

By:

/s/

Peter Ludlum

Peter

Ludlum

Interim

Chief Executive Officer and Interim Chief Financial Officer

EX-99.1

Filename: ex99-1.htm · Sequence: 2

Exhibit

99.1

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.

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:

https://www.pulmatrix.com/pipeline.html.

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 https://www.eossenolytix.com.

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

chuck@lifesciadvisors.com

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