[8-K] MANNKIND CORP Reports Material Event

Rhea-AI Filing Summary

MannKind Corporation is discontinuing its Phase 3 trial of nebulized clofazimine (MNKD-101) for refractory nontuberculous mycobacterial lung disease after an interim analysis for the first 46 participants who completed the double-blind phase showed no sputum culture conversions, indicating futility.

The data safety monitoring board reviewed the results on November 8, 2025 and agreed with stopping the study; no safety issues were identified. MannKind plans to investigate the outcome and apply learnings to MNKD-102, a dry powder clofazimine formulation progressing from pre-clinical toward Phase 1.

Positive

• None.

Negative

• Phase 3 MNKD-101 discontinued for futility after 46 participants showed no sputum culture conversions; DSMB agreed on November 8, 2025.

Insights

Biotech clinical development analyst

Phase 3 halted for futility; safety clean, pipeline pivots to MNKD-102.

MannKind halted the Phase 3 MNKD-101 trial in refractory NTM lung disease after an interim analysis found zero sputum culture conversions among the first 46 participants completing the double-blind phase. The DSMB met on November 8, 2025 and agreed with discontinuation due to futility.

No safety issues were identified by the DSMB in this or prior meetings, pointing to an efficacy shortfall rather than tolerability concerns. The company will examine causes and channel findings into MNKD-102, a dry powder clofazimine program moving from pre-clinical toward Phase 1.

Near-term impact centers on the loss of this late-stage asset and the shift to an earlier-stage formulation. Subsequent disclosures may detail MNKD-102’s initiation and design; outcomes will depend on study execution and whether a different delivery route affects efficacy.

MANNKIND CORP false 0000899460 0000899460 2025-11-08 2025-11-08

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): November 8, 2025

MannKind Corporation

(Exact Name of Registrant as Specified in Charter)

Delaware		000-50865		13-3607736
(State or Other Jurisdiction of Incorporation)		(Commission File Number)		(I.R.S. Employer Identification Number)

1 Casper Street, Danbury, Connecticut 06810

(Address of Principal Executive Offices) (Zip Code)

(818) 661-5000

(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 (see General Instruction A.2. of Form 8-K):

☐ 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 (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. ☐

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 $0.01 per share		MNKD		The Nasdaq Stock Market LLC

Item 8.01 Other Events.

On November 10, 2025, MannKind Corporation (the “Company”) announced that it is discontinuing its Phase 3 clinical trial evaluating nebulized inhalation suspension of clofazimine (“MNKD-101”) for the treatment of refractory nontuberculous mycobacterial (“NTM”) lung disease (the “ICoN-1 Study”). The decision to discontinue the trial follows an analysis of sputum culture conversion data, conducted as part of routine study monitoring and in accordance with the trial protocol, for the first 46 participants who had completed the double-blind treatment phase of the study. None of these 46 participants showed evidence of sputum culture conversion, raising concerns regarding the likelihood of achieving the study’s key primary endpoint. Following an ad hoc meeting of the data safety monitoring board (“DSMB”) for the ICoN-1 Study on November 8, 2025, the DSMB reviewed the data and agreed with the decision to discontinue the trial due to futility. In this meeting and in all past DSMB meetings, no safety issues were found.

The Company intends to investigate the reasons for this outcome and use the findings to help guide the ongoing development of MNKD-102, the dry powder formulation of clofazimine, which is in the process of advancing from pre-clinical development towards Phase 1.

Forward-Looking Statements

Statements in this report that are not statements of historical fact are forward-looking statements. Words such as “plans,” “expects,” “intend,” “will,” “anticipate,” “potential” and similar expressions are intended to identify forward-looking statements. Forward-looking statements include statements regarding the future development of MNKD-102. These forward-looking statements are based upon the Company’s current expectations. Actual results and the timing of events could differ materially from those anticipated in such forward-looking statements as a result of various risks and uncertainties, which include risks and uncertainties regarding pipeline development and capital resource considerations. Additional risks are detailed in the Company’s filings with the Securities and Exchange Commission (“SEC”), including under the heading “Risk Factors” in MannKind’s Quarterly Report on Form 10-Q for the quarter ended September 30, 2025, filed with the SEC on November 5, 2025. You are cautioned not to place undue reliance on these forward-looking statements, which speak only as of the date of this report. All forward-looking statements are qualified in their entirety by this cautionary statement, and the Company undertakes no obligation to revise or update any forward-looking statements to reflect events or circumstances after the date of this report.

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.

				MannKind Corporation
Date: November 10, 2025				By:		/s/ David Thomson
						David Thomson, Ph.D., J.D.
						Executive Vice President, General Counsel and Secretary

FAQ

What did MannKind (MNKD) announce in this 8-K?

MannKind discontinued its Phase 3 trial of nebulized clofazimine (MNKD-101) for refractory NTM lung disease after an interim analysis showed no sputum culture conversions.

What data led to stopping the MNKD-101 study?

Among the first 46 participants who completed the double-blind phase, none achieved sputum culture conversion, prompting a futility decision.

Did the DSMB identify any safety issues in the MNKD-101 trial?

No. The DSMB reported no safety issues in the November 8, 2025 meeting or prior meetings.

What is next for MannKind’s clofazimine programs?

The company will investigate the Phase 3 outcome and use findings to guide MNKD-102, a dry powder formulation moving from pre-clinical toward Phase 1.

What condition was MNKD-101 targeting?

MNKD-101 was being evaluated for refractory nontuberculous mycobacterial (NTM) lung disease.

What does 'futility' mean in this context?

Futility indicates the trial was unlikely to meet its primary endpoint based on interim data, leading to discontinuation.