MannKind files prospectus for common stock sale

MannKind Corporation (MNKD) reported that on August 21, 2026 it filed a prospectus supplement to its automatic shelf registration statement on Form S-3 (Registration No. 333-285286) with the SEC.

Rhea-AI Filing Summary

MannKind Corporation (MNKD) reported that on August 21, 2026 it filed a prospectus supplement to its automatic shelf registration statement on Form S-3 (Registration No. 333-285286) with the SEC. On the same date, MannKind furnished an opinion of Cooley LLP regarding the legality of the issuance and sale of the common stock described in that prospectus supplement, included as Exhibit 5.1, together with Cooley LLP’s related consent as Exhibit 23.1.

Filing Explained

The August 21 8-K documents a prospectus supplement and related legal opinion under MannKind’s automatic Form S-3 shelf; this establishes capacity for future registered sales, not a completed share sale or disclosed issuance.

8-K Event Classification

2 items: 8.01, 9.01

2 items

Item 8.01 Other Events Other

Voluntary disclosure of events the company deems important to shareholders but not covered by other items.

Item 9.01 Financial Statements and Exhibits Exhibits

Financial statements, pro forma financial information, or exhibit attachments filed with this report.

Key Figures

Form S-3 Registration No.: 333-285286 Common stock par value: $0.01 per share Exhibit 5.1: 5.1 +4 more

7 metrics

Form S-3 Registration No. 333-285286 Automatic shelf registration statement referenced by MannKind Corporation

Common stock par value $0.01 per share Par value of MannKind Corporation common stock listed under Section 12(b)

Exhibit 5.1 5.1 Opinion of Cooley LLP on legality of issuance and sale of common stock

Exhibit 23.1 23.1 Consent of Cooley LLP, included in Exhibit 5.1

Exhibit 104 104 Cover Page Interactive Data File embedded in the Inline XBRL document

Commission File Number 000-50865 MannKind Corporation’s Exchange Act file number

Employer Identification Number 13-3607736 IRS Employer Identification No. for MannKind Corporation

Key Terms

automatic shelf registration statement, prospectus supplement, opinion of Cooley LLP, Inline XBRL

4 terms

automatic shelf registration statement regulatory

"filed a prospectus supplement to its automatic shelf registration statement on Form S-3"

An automatic shelf registration statement is a pre-approved filing that companies submit to securities regulators, allowing them to sell new shares or bonds quickly and efficiently when needed. It acts like a standing permit, enabling the company to raise money without going through a lengthy approval process each time, which can be helpful for responding promptly to market opportunities or needs. For investors, it provides transparency about the company's ability to raise funds and signals planning flexibility.

prospectus supplement regulatory

"filed a prospectus supplement to its automatic shelf registration statement"

A prospectus supplement is an additional document provided alongside a company's main offering details, offering updated or extra information about a specific financial product being sold. It helps investors understand the latest terms, risks, and details of the investment, similar to how an update or revision clarifies or expands on original instructions, ensuring they have current and complete information before making a decision.

opinion of Cooley LLP regulatory

"for the purpose of filing the opinion of Cooley LLP relating to the legality"

Inline XBRL technical

"Cover Page Interactive Data File (embedded within the Inline XBRL document)"

Inline XBRL is a file format for financial filings that embeds machine-readable data tags directly inside the human-readable report, so the same document can be read by people and parsed by software. For investors it makes extracting, comparing and verifying financial numbers faster and more reliable—like a grocery list where each item also has a barcode—reducing manual errors and speeding up analysis.

FAQ

AI-generated questions and answers. How Rhea-AI works. Not financial advice.

What did MNKD announce regarding its Form S-3 shelf on August 21, 2026?

MannKind Corporation announced that on August 21, 2026 it filed a prospectus supplement to its automatic shelf registration statement on Form S-3 (No. 333-285286) and provided an opinion of Cooley LLP on the legality of the common stock to be issued under that supplement.

What is the purpose of the Cooley LLP opinion for MNKD?

The Cooley LLP opinion, filed as Exhibit 5.1, addresses the legality of the issuance and sale of MannKind Corporation’s common stock covered by the prospectus supplement to its Form S-3 automatic shelf registration statement.

Which registration statement is referenced in MannKind (MNKD)’s disclosure?

MannKind references its automatic shelf registration statement on Form S-3 with Registration No. 333-285286, for which it filed a related prospectus supplement and legal opinion on August 21, 2026.

Which exhibits did MNKD file in connection with the prospectus supplement?

MannKind filed Exhibit 5.1, the opinion of Cooley LLP regarding the common stock’s legality, and Exhibit 23.1, Cooley LLP’s consent (included in Exhibit 5.1), along with Exhibit 104, the cover page Inline XBRL data file.

Does this MNKD disclosure describe financial results or business operations?

No. The disclosure focuses on procedural matters: a prospectus supplement to Form S-3 and the related legal opinion and consent from Cooley LLP concerning MannKind’s common stock issuance.

AI-generated analysis. How Rhea-AI works. Not financial advice.

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Available on EDGAR 08/21/2026 - 04:11 PM Accepted by SEC EDGAR 08/21/2026 - 04:10 PM Learn about SEC filing dates

MANNKIND CORP false 0000899460 0000899460 2026-08-21 2026-08-21

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): August 21, 2026

MannKind Corporation

(Exact name of Registrant as Specified in Its Charter)

Delaware		000-50865		13-3607736
(State or Other Jurisdiction of Incorporation)		(Commission File Number)		(IRS Employer Identification No.)

1 Casper Street
Danbury, Connecticut		06810
(Address of Principal Executive Offices)		(Zip Code)

Registrant’s Telephone Number, Including Area Code: (818) 661-5000

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 each exchange on which registered
Common Stock, par value $0.01 per share		MNKD		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 8.01 Other Events.

On August 21, 2026, MannKind Corporation (the “Company”) filed a prospectus supplement to its automatic shelf registration statement on Form S-3 (Registration No. 333-285286) with the Securities and Exchange Commission. This Current Report on Form 8-K is being filed for the purpose of filing the opinion of Cooley LLP relating to the legality of the issuance and sale of the shares of common stock of the Company set forth in the prospectus supplement, which opinion is filed as Exhibit 5.1 hereto.

Item 9.01 Financial Statements and Exhibits.

(d) Exhibits.

Exhibit No.		Description
5.1		Opinion of Cooley LLP
23.1		Consent of Cooley LLP (included in Exhibit 5.1)
104		Cover Page Interactive Data File (embedded within the 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.

				MannKind Corporation
Date: August 21, 2026				By:		/s/ David Thomson
						David Thomson, Ph.D., J.D.
						Executive Vice President, General Counsel and Secretary

Filing Exhibits & Attachments

4 documents

Other Documents

• EX-5.1 EX-5.1 9.1 KB
• EX-101 XBRL TAXONOMY EXTENSION SCHEMA 3.1 KB
• EX-101 XBRL TAXONOMY EXTENSION LABEL LINKBASE 16.8 KB
• EX-101 XBRL TAXONOMY EXTENSION PRESENTATION LINKBASE 10.6 KB