MAIA Biotechnology (NYSE: MAIA) starts Ateganosine Phase 3 trial and notes insider buying

Rhea-AI Filing Summary

MAIA Biotechnology filed an 8-K to highlight several corporate updates announced on December 11, 2025. The company reported that its leadership team has continued insider purchases of MAIA stock in 2025, signaling ongoing management engagement with the business. MAIA also announced that the first patient has been dosed in its THIO-104 Phase 3 pivotal trial evaluating its drug candidate Ateganosine as a third-line treatment for advanced non-small cell lung cancer. A third press release emphasized the momentum behind Ateganosine as this pivotal Phase 3 trial gets underway, underscoring MAIA’s focus on advancing its oncology pipeline.

Insights

Biotech & clinical development analyst

MAIA advances its lead cancer drug into a pivotal Phase 3 trial.

MAIA Biotechnology is drawing attention to two themes: insider buying by leadership and progression of its lead asset Ateganosine into the THIO-104 Phase 3 pivotal trial. Dosing the first patient marks the operational start of a large, confirmatory study in advanced non-small cell lung cancer for use as a third-line treatment.

Pivotal Phase 3 trials are typically designed to generate data that can support future regulatory submissions, but outcomes remain uncertain and subject to the clinical and regulatory risks highlighted in the company’s forward-looking statements. The insider buying mentioned in a separate press release indicates management is purchasing additional shares, though no amounts or terms are detailed here, so its magnitude cannot be assessed from this excerpt.

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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): December 11, 2025

MAIA Biotechnology, Inc.

(Exact name of registrant as specified in its charter)

Delaware		001-41455		83-1495913
(State or other jurisdiction of incorporation)		(Commission File Number)		(IRS Employer Identification No.)

444 West Lake Street, Suite 1700
Chicago, IL		60606
(Address of principal executive offices)		(Zip Code)

(312) 416-8592

(Registrant’s telephone number, including area code)

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 each exchange on which registered
Common Stock		MAIA		NYSE American

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (17 CFR §230.405) or Rule 12b-2 of the Securities Exchange Act of 1934 (17 CFR §240.12b-2).

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.

1. On December 11, 2025, MAIA Biotechnology, Inc. (the “Company”) issued a press release entitled “MAIA Leadership Continues Insider Buying in 2025 and Trial Data Signals Breakout Potential” A copy of the press release is attached hereto as Exhibit 99.1 and is incorporated herein by reference.

2. On December 11, 2025, the Company issued a press release entitled “MAIA Biotechnology Announces First Patient Dosed in THIO-104 Phase 3 Pivotal Trial Evaluating Ateganosine as Third-Line Treatment for Advanced Non-Small Cell Lung Cancer” A copy of the press release is attached hereto as Exhibit 99.2 and is incorporated herein by reference.

3 On December 11, 2025, the Company issued a press release entitled “MAIA’s Ateganosine Surges Ahead with Breakthrough Momentum as Pivotal Phase 3 Trial Initiates” A copy of the press release is attached hereto as Exhibit 99.3 and is incorporated herein by reference.

Forward-looking Statements

The Company cautions that all statements, other than statements of historical facts, contained in this Current Report on Form 8-K, or furnished herewith, are forward-looking statements. Forward-looking statements are subject to known and unknown risks, uncertainties, and other factors that may cause our or our industry’s actual results, levels or activity, performance or achievements to be materially different from those anticipated by such statements. The use of words such as “may,” “might,” “will,” “should,” “could,” “expect,” “plan,” “anticipate,” “believe,” “estimate,” “project,” “intend,” “future,” “potential,” or “continue,” and other similar expressions are intended to identify forward looking statements. However, the absence of these words does not mean that statements are not forward-looking. All forward-looking statements are based on current estimates, assumptions and expectations by our management that, although we believe to be reasonable, are inherently uncertain. Any forward-looking statement expressing an expectation or belief as to future events is expressed in good faith and believed to be reasonable at the time such forward-looking statement is made. However, these statements are not guarantees of future events and are subject to risks and uncertainties and other factors beyond our control that may cause actual results to differ materially from those expressed in any forward-looking statement, including, but not limited to: (i) the initiation, timing, cost, progress and results of our preclinical and clinical studies and our research and development programs, (ii) our ability to advance product candidates into, and successfully complete, clinical studies, (iii) the timing or likelihood of regulatory filings and approvals, (iv) our ability to develop, manufacture and commercialize our product candidates and to improve the manufacturing process, (v) the rate and degree of market acceptance of our product candidates, (vi) the size and growth potential of the markets for our product candidates and our ability to serve those markets, and (vii) our expectations regarding our ability to obtain and maintain intellectual property protection for our product candidates. Any forward-looking statement speaks only as of the date on which it was made. The Company undertakes no obligation to publicly update or revise any forward-looking statement, whether as a result of new information, future events or otherwise, except as required by law.

Item 9.01 Financial Statements and Exhibits.

(d) Exhibits.

Exhibit No.		Description
99.1		Press Release dated December 11, 2025 (Insider buying)
99.2		Press Release dated December 11, 2025 (First Patient Dosed in THIO-104 Phase 3 Pivotal Trial)
99.3		Press Release dated December 11, 2025 (MAIA’s Ateganosine Surges Ahead)
104		Cover Page Interactive Data File (embedded within the Inline XBRL document)

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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.

Dated: December 11, 2025

	MAIA BIOTECHNOLOGY, INC.
	By:	/s/ Vlad Vitoc
	Name:	Vlad Vitoc
	Title:	Chief Executive Officer

3

FAQ

What did MAIA (MAIA) disclose in this 8-K filing?

MAIA Biotechnology reported that it issued three press releases on December 11, 2025: one on continued insider buying by leadership, and two highlighting the start and momentum of its THIO-104 Phase 3 pivotal trial for Ateganosine in advanced non-small cell lung cancer.

What is the THIO-104 Phase 3 pivotal trial announced by MAIA (MAIA)?

The THIO-104 Phase 3 pivotal trial is a clinical study evaluating MAIA’s drug candidate Ateganosine as a third-line treatment for patients with advanced non-small cell lung cancer, and the company has dosed the first patient in this trial.

What insider activity did MAIA (MAIA) reference in the filing?

MAIA noted a press release titled “MAIA Leadership Continues Insider Buying in 2025 and Trial Data Signals Breakout Potential,” indicating ongoing stock purchases by company leadership, though specific transaction details are not included in this 8-K text.

How is Ateganosine being positioned in MAIA Biotechnology’s pipeline?

Ateganosine is being advanced in a pivotal Phase 3 trial as a potential third-line treatment for advanced non-small cell lung cancer, and MAIA described its progress as having “breakthrough momentum” as the THIO-104 study initiates.

Does this 8-K include MAIA (MAIA) financial results or earnings data?

No, this 8-K focuses on other events, specifically press releases about insider buying and the initiation of a pivotal Phase 3 trial for Ateganosine, rather than financial results or earnings metrics.

What risks does MAIA highlight regarding its forward-looking statements?

MAIA notes that statements about its studies and product candidates are forward-looking and subject to risks such as the timing, cost, progress and results of preclinical and clinical studies, regulatory filings and approvals, commercialization efforts, market acceptance, and intellectual property protection.