MannKind Corp (MNKD) insider filing shows CEO option exercises, share sales

Rhea-AI Filing Summary

MannKind Corp Chief Executive Officer and director Michael Castagna reported stock option exercises and related share sales in recent insider transactions. On 12/12/2025 he exercised 20,806 employee stock options at $4.55 per share and sold 20,806 shares of common stock at $6, leaving him with 2,504,792 common shares held directly. On 12/16/2025 he exercised a further 21,310 options at $4.55 and sold 21,310 common shares at $6, again ending with 2,504,792 directly held shares. Following these trades, he beneficially owns 15,804 employee stock options with a $4.55 exercise price expiring on 05/19/2026. The transactions were carried out under a Rule 10b5-1 trading plan established on August 8, 2025.

SEC Form 4

FORM 4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL

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Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

X

Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

1. Name and Address of Reporting Person^*

Castagna Michael

(Last) (First) (Middle)

1 CASPER STREET

(Street)

DANBURY CT 06810

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
MANNKIND CORP [ MNKD ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

X	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	Chief Executive Officer

3. Date of Earliest Transaction (Month/Day/Year)
12/12/2025

4. If Amendment, Date of Original Filed (Month/Day/Year)

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Common Stock, $0.01 Par Value	12/12/2025		M		20,806	A	$4.55	2,525,598	D
Common Stock, $0.01 Par Value	12/12/2025		S(1)		20,806	D	$6	2,504,792	D
Common Stock, $0.01 Par Value	12/16/2025		M		21,310	A	$4.55	2,526,102	D
Common Stock, $0.01 Par Value	12/16/2025		S(1)		21,310	D	$6	2,504,792	D

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
Employee Stock Option (Right to Buy)	$4.55	12/12/2025		M			7,920	03/14/2020	05/19/2026	Common Stock, $0.01 Par Value	7,920	$0	0	D
Employee Stock Option (Right to Buy)	$4.55	12/12/2025		M			12,886	08/07/2023	05/19/2026	Common Stock, $0.01 Par Value	12,886	$0	37,114	D
Employee Stock Option (Right to Buy)	$4.55	12/16/2025		M			21,310	08/07/2023	05/19/2026	Common Stock, $0.01 Par Value	21,310	$0	15,804	D

Explanation of Responses:

1. Transaction occurred pursuant to Rule 10b5-1 Plan established August 8, 2025.

	/s/ Michael Castagna	12/16/2025
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
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FAQ

What insider transactions did MannKind Corp (MNKD) report for December 2025?

MannKind Corp reported that CEO and director Michael Castagna exercised employee stock options and sold common shares on 12/12/2025 and 12/16/2025, with each option exercise matched by a sale of the same number of shares.

How many MannKind Corp (MNKD) shares does CEO Michael Castagna hold after these trades?

After the reported transactions, CEO Michael Castagna beneficially owns 2,504,792 shares of MannKind Corp common stock, held directly.

At what prices were the MannKind Corp (MNKD) options exercised and shares sold?

The employee stock options were exercised at an exercise price of $4.55 per share, and the corresponding common shares were sold at a price of $6 per share.

What stock options remain outstanding for MannKind Corp (MNKD)'s CEO after these transactions?

Following the reported transactions, Michael Castagna beneficially owns 15,804 employee stock options with an exercise price of $4.55 per share that expire on 05/19/2026.

Were the MannKind Corp (MNKD) insider trades executed under a Rule 10b5-1 plan?

Yes. The filing states that the transactions occurred pursuant to a Rule 10b5-1 plan that was established on August 8, 2025.

Is Michael Castagna both a director and an officer of MannKind Corp (MNKD)?

Yes. The report identifies Michael Castagna as a Director and an Officer, serving as MannKind Corp’s Chief Executive Officer.

What types of securities are involved in the MannKind Corp (MNKD) insider filing?

The transactions involve common stock, $0.01 par value, and employee stock options (right to buy) with a $4.55 exercise price expiring on 05/19/2026.