Form 8-K

8-K — Armata Pharmaceuticals, Inc.

Accession: 0001104659-26-048997

Filed: 2026-04-27

Period: 2026-04-24

CIK: 0000921114

SIC: 2836 (BIOLOGICAL PRODUCTS (NO DIAGNOSTIC SUBSTANCES))

Item: Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers: Compensatory Arrangements of Certain Officers

Item: Regulation FD Disclosure

Item: Financial Statements and Exhibits

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UNITED STATES

SECURITIES AND

EXCHANGE COMMISSION

Washington, DC

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 24, 2026

ARMATA PHARMACEUTICALS, INC.

(Exact name of Registrant as specified in

its charter)

Washington

001-37544

91-1549568

(State or other jurisdiction

of incorporation or

organization)

(Commission File Number)

(IRS Employer Identification No.)

5005 McConnell Avenue

Los Angeles, California

90066

(Address of principal executive offices)

(Zip Code)

(310) 655-2928

(Registrant’s Telephone number)

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))

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. ¨

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

ARMP

NYSE American

Item 5.02

Departure of Directors or Principal Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers.

On April 27, 2026, Armata Pharmaceuticals, Inc. (the “Company”)

announced that the Board of Directors

(the “Board”) appointed Dr. Daniel Gilmer, 39, as

a member of the Board, effective as of April 24, 2026, to serve until the Company’s next annual meeting of the Company’s

shareholders.

The committee assignments of Dr. Gilmer have not been determined

as of the time of this filing.

Dr. Gilmer will participate in the Company’s standard non-management

director compensation arrangement. The Company pays non-management directors a retainer of $40,000 per year, payable in cash. Dr. Gilmer

will also be eligible to receive equity awards in amounts to be determined by the Board pursuant to the Company’s 2016 Stock Incentive

Plan, as amended (the “Plan”). A copy of the Plan was previously filed with the SEC as Exhibit 99.1 to the Company’s

Registration Statement on Form S-8 filed on June 10, 2019. In connection with his appointment, Dr. Gilmer is expected to

receive an option award to purchase 51,280 shares of the Company’s common stock, at an exercise price equal to the fair market value

of one share of the Company’s common stock on the date of grant, vesting in equal installments over a three-year period. The awards

will be governed by the form of Stock Option Grant Notice and Option Agreement previously filed with the SEC on the Company’s Quarterly

Report on Form 10-Q filed on August 14, 2019. The Company also entered into an indemnity agreement with Dr. Gilmer, a form

of which was previously filed with the SEC as Exhibit 99.2 to the Company’s Current Report on Form 8-K, filed on January 19,

2016.

There are no arrangements or understandings between Dr. Gilmer

and any other persons pursuant to which he was selected as a member of the Board. There are also no family relationships between Dr. Gilmer

and any director or executive officer of the Company and he has no direct or indirect material interest in any transaction required

to be disclosed pursuant to Item 404(a) of Regulation S-K.

Item 7.01

Regulation FD Disclosure.

On April 27, 2026, the Company issued a press release announcing

the appointment of Dr. Gilmer. The full text of the press release issued in connection with this announcement is furnished as Exhibit 99.1

to this Current Report on Form 8-K.

The information in this Item 7.01 and the attached Exhibit 99.1

is being furnished and shall not be deemed “filed” for the purposes of Section 18 of the Securities Exchange Act of 1934,

as amended, or otherwise subject to the liabilities of that Section. The information in this Item 7.01 and the attached Exhibit 99.1

shall not be incorporated by reference into any registration statement or other document pursuant to the Securities Act of 1933, as amended.

Item 9.01 Financial Statements and Exhibits.

(d)Exhibits.

Exhibit

No.

Description

99.1

Press Release, dated April 27, 2026.

104

Cover Page Interactive Data File (embedded within 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: April 27, 2026

Armata Pharmaceuticals, Inc.

By:

/s/ David House

Name:

David House

Title:

Senior Vice President, Finance and Principal Financial Officer

EX-99.1 — EXHIBIT 99.1

EX-99.1

Filename: tm2612716d1_ex99-1.htm · Sequence: 2

Exhibit 99.1

Armata Pharmaceuticals Announces Appointment

of Biopharmaceutical Commercial Executive

Daniel B. Gilmer, Ph.D. to its Board of Directors

LOS ANGELES, Calif., April 27, 2026 -- Armata

Pharmaceuticals, Inc. (NYSE American: ARMP) (“Armata” or the “Company”), a late clinical-stage biotechnology

company focused on the development of high-purity, pathogen-specific bacteriophage therapeutics for the treatment of antibiotic-resistant

and difficult-to-treat bacterial infections, today announced that Daniel B. Gilmer, Ph.D. has joined the Company’s Board of Directors,

effective April 24, 2026. Dr. Gilmer has served as Senior Director, Commercial Quality U.S. Team Lead at Pfizer Inc. (“Pfizer”)

since February 2025.

“I am pleased to welcome Daniel to our Board

and look forward to leveraging his many years of experience spanning scientific discovery, commercial strategy, and patient access,”

stated Robin C. Kramer, Chair of Armata’s Board of Directors. “Daniel has discovered and helped advance first-in-class anti-infective

candidates and has played pivotal roles in the launch and commercialization of breakthrough therapies and diagnostics, including leading

the U.S. launch of PAXLOVIDTM. His perspectives on antimicrobial resistance, diagnostics, and access to innovation will be

invaluable as we continue to advance our phage-based pipeline to commercialization.”

“I am very excited to join Armata’s

Board and work alongside my fellow Directors and the leadership team to help the Company achieve its clinical and commercial goals,”

stated Dr. Gilmer. “Armata is developing precisely targeted bacteriophage therapeutics that have the potential to address the

growing global crisis of antibiotic resistance. I look forward to contributing my experience in launching innovative anti-infectives and

access-oriented initiatives to support this mission.”

Daniel B. Gilmer, Ph.D. is an accomplished

healthcare executive. At Pfizer, he leads an organization responsible for quality and promotional review across 50+ U.S. brands. His team

works closely with medical, legal, and regulatory subject matter experts to advise commercial stakeholders on content quality, compliance,

and risk-benefit balance. Previously, from April 2022 to February 2025, Dr. Gilmer led cross-functional teams in Pfizer’s

Antiviral and Diagnostics Business, where he launched PAXLOVIDTM in the United States as it received New Drug Approval from

the U.S. Food and Drug Administration (the “FDA”). Earlier at Pfizer, from April 2021 to April 2022, Dr. Gilmer

worked in Inflammation & Immunology Commercial Development, where he helped shape strategy for a portfolio of rheumatology and

immunology assets. Dr. Gilmer joined Pfizer in Research & Development in May 2019, where he contributed to Pfizer’s

COVID-19 vaccine-enabling operating model and R&D portfolio strategy.

Dr. Gilmer is an equal co-inventor on the

patent for Exebacase (also termed “CF-301” or “PlySs2”), a first-in-class Streptococcus bacteriophage lysin.

Exebacase received Fast Track and Breakthrough Therapy designations from the FDA before advancing to Phase 3 clinical trials. Dr. Gilmer

has authored multiple peer-reviewed publications on phage lysins and antimicrobial resistance. Prior to joining Pfizer, Dr. Gilmer

worked at McKinsey & Co. focusing on commercial growth strategies, market access, and lean manufacturing in the United States,

Canada, and France. Earlier in his career, he conducted microbiology and infectious disease research at leading academic institutions

and the National Institutes of Health.

He has a Ph.D. in Microbiology from Rockefeller

University (RU) and a B.S. from Howard University. As an RU alum, he serves on both the RU Board of Trustees Educational Affairs Committee

and the RU Ford Center Incubator selection committee. He is a member of the New York Academy of Sciences and a term member at the Council

on Foreign Relations.

About Armata Pharmaceuticals, Inc.

Armata is a late clinical-stage biotechnology

company focused on the development of high-purity pathogen-specific bacteriophage therapeutics for the treatment of antibiotic-resistant

and difficult-to-treat bacterial infections using its proprietary bacteriophage-based technology. Armata is developing and advancing a

broad pipeline of natural and synthetic phage candidates, including clinical candidates for Pseudomonas aeruginosa, S. aureus,

and other important pathogens. Armata is committed to advancing phage therapy with drug development expertise that spans bench to clinic

including in-house phage-specific current Good Manufacturing Practices (“cGMP”) manufacturing to support full commercialization.

Forward Looking Statements

This communication contains “forward-looking”

statements as defined by the Private Securities Litigation Reform Act of 1995. These statements relate to future events, results or to

Armata’s future financial performance and involve known and unknown risks, uncertainties and other factors which may cause Armata’s

actual results, performance or events to be materially different from any future results, performance or events expressed or implied by

the forward-looking statements. In some cases, you can identify these statements by terms such as “anticipate,” “believe,”

“could,” “estimate,” “expect,” “intend,” “may,” “plan,” “potential,”

“predict,” “project,” “should,” “will,” “would” or the negative of those terms,

and similar expressions. These forward-looking statements reflect management’s beliefs and views with respect to future events and

are based on estimates and assumptions as of the date of this communication and are subject to risks and uncertainties including risks

related to Armata’s development of bacteriophage-based therapies; Armata's planned clinical trials; ability to staff and maintain

its production facilities under fully compliant cGMP; ability to meet anticipated milestones in the development and testing of the relevant

product; ability to be a leader in the development of phage-based therapeutics; ability to achieve its vision, including improvements

through engineering and success of clinical trials; ability to successfully complete preclinical and clinical development of, and obtain

regulatory approval of its product candidates and commercialize any approved products on its expected timeframes or at all; and Armata’s

estimates regarding anticipated operating losses, capital requirements and needs for additional funds. Additional risks and uncertainties

relating to Armata and its business can be found under the caption “Risk Factors” and elsewhere in Armata’s filings

and reports with the U.S. Securities and Exchange Commission (the “SEC”), including in Armata’s Annual Report on Form 10-K,

filed with the SEC on March 25, 2026, and in its subsequent filings with the SEC.

Armata expressly disclaims any obligation or undertaking

to release publicly any updates or revisions to any forward-looking statements contained herein to reflect any change in Armata’s

expectations with regard thereto or any change in events, conditions or circumstances on which any such statements are based.

Media Contacts:

At Armata:

Pierre Kyme

ir@armatapharma.com

310-665-2928

Investor Relations:

Joyce Allaire

LifeSci Advisors, LLC

jallaire@lifesciadvisors.com

212-915-2569

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