Cidara (CDTX) director stock options paid out in Merck merger

Rhea-AI Filing Summary

Cidara Therapeutics director Carin Canale-Theakston reported the cash-out of stock options in connection with Cidara’s acquisition by Merck. On January 7, 2026, a Merck subsidiary completed a tender offer for all outstanding Cidara common and Series A preferred shares and then merged into Cidara, which became a wholly owned Merck subsidiary.

Immediately before the merger became effective, each of the director’s outstanding stock options became fully vested and exercisable, then was cancelled at the effective time and converted into the right to receive cash. The cash amount for each option equals the number of common shares subject to the option multiplied by the excess of $221.50 per share over the option’s exercise price. The reported option grants, which had exercise prices ranging from $10.6 to $50.2 and various expiration dates from 2031 to 2035, now show 0 derivative securities owned following these transactions. All exercise prices and share amounts were adjusted for Cidara’s 1-for-20 reverse stock split on April 24, 2024.

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

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X

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

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^*

Canale-Theakston Carin

(Last) (First) (Middle)

C/O CIDARA THERAPEUTICS, INC.

6310 NANCY RIDGE DRIVE SUITE 101

(Street)

SAN DIEGO CA 92121

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
Cidara Therapeutics, Inc. [ CDTX ]

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

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

3. Date of Earliest Transaction (Month/Day/Year)
01/07/2026

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

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
Stock Option (right to buy)	$50.2(1)	01/07/2026		D			1,750(1)	(2)(3)	01/21/2031	Common Stock	1,750	(2)(3)	0	D
Stock Option (right to buy)	$38.4(1)	01/07/2026		D			875(1)	(2)(3)	06/22/2031	Common Stock	875	(2)(3)	0	D
Stock Option (right to buy)	$10.6(1)	01/07/2026		D			1,400(1)	(2)(3)	06/21/2032	Common Stock	1,400	(2)(3)	0	D
Stock Option (right to buy)	$23.4(1)	01/07/2026		D			2,125(1)	(2)(3)	06/21/2033	Common Stock	2,125	(2)(3)	0	D
Stock Option (right to buy)	$12.64	01/07/2026		D			2,125	(2)(3)	07/17/2034	Common Stock	2,125	(2)(3)	0	D
Stock Option (right to buy)	$22.81	01/07/2026		D			16,000	(2)(3)	12/16/2034	Common Stock	16,000	(2)(3)	0	D
Stock Option (right to buy)	$21.31	01/07/2026		D			11,100	(2)(3)	06/17/2035	Common Stock	11,100	(2)(3)	0	D

Explanation of Responses:

1. The exercise price and the number of securities reported herein have been adjusted to reflect the 1-for-20 reverse stock split effected by the Issuer on April 24, 2024.

2. Pursuant to the Agreement and Plan of Merger (the "Merger Agreement"), dated November 13, 2025, by and among Cidara Therapeutics, Inc. (the "Issuer"), Merck Sharp & Dohme LLC ("Merck") and Caymus Purchaser, Inc., a wholly owned subsidiary of Merck ("Purchaser"), on January 7, 2026, Purchaser completed a tender offer to acquire (i) all outstanding shares of common stock of the Issuer, par value $0.0001 per share (each, a "Common Share") and (ii) all outstanding shares of Series A Convertible Voting Preferred Stock of the Issuer, par value $0.0001 per share and thereafter merged with and into the Issuer, with the Issuer continuing as the surviving corporation and a wholly owned subsidiary of Merck (the "Merger").

3. As of immediately prior to and contingent upon the occurrence of the effective time of the Merger, pursuant to the Merger Agreement, each outstanding option became fully vested and exercisable, and to the extent outstanding and unexercised as of immediately before the effective time of the Merger, was cancelled at the effective time of the Merger and converted into the right to receive cash, without interest, subject to any applicable withholding of taxes, in an amount equal to the product of (i) the total number of Common Shares subject to such option immediately prior to the effective time of the Merger multiplied by (ii) the excess of (x) $221.50 per Common Share over (y) the exercise price payable per Common Share under such option.

Remarks:

	/s/ Shane Ward, Attorney-in-Fact	01/07/2026
	** 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

Who is the reporting insider in the Cidara (CDTX) Form 4?

The reporting person is Carin Canale-Theakston, who is identified as a director of Cidara Therapeutics, Inc. and is not listed as an officer or 10% owner.

What happened to Carin Canale-Theakstons Cidara stock options on January 7, 2026?

On January 7, 2026, all of the directors reported Cidara stock options (rights to buy common stock) were reported as disposed of with 0 derivative securities remaining beneficially owned afterward. Under the merger terms, each outstanding option became fully vested and exercisable, then was cancelled at the mergers effective time and converted into a cash payment right.

How were Cidara options treated in the Merck merger described in this Form 4?

The footnotes explain that, pursuant to the Merger Agreement among Cidara, Merck Sharp & Dohme LLC, and Caymus Purchaser, Inc., each outstanding option became fully vested and exercisable immediately prior to the merger. Any option that remained outstanding and unexercised at the effective time was cancelled and converted into the right to receive cash, without interest and subject to tax withholding.

What cash amount per Cidara share was used to calculate the option payouts?

The cash payment for each option is based on $221.50 per Common Share. For each option, the holder is entitled to an amount equal to the total number of common shares subject to that option multiplied by the excess of $221.50 per share over the options exercise price per share.

What merger and tender offer involving Cidara Therapeutics are disclosed here?

The filing states that under the Merger Agreement dated November 13, 2025, a Merck subsidiary completed a tender offer on January 7, 2026 to acquire all outstanding Cidara common stock and Series A Convertible Voting Preferred Stock. After the tender offer, the Purchaser merged with and into Cidara, and Cidara continued as the surviving corporation and a wholly owned subsidiary of Merck.

Why were the exercise prices and option share amounts adjusted in this Cidara Form 4?

A footnote explains that the exercise price and the number of securities reported were adjusted to reflect Cidaras 1-for-20 reverse stock split, which was effected on April 24, 2024. This adjustment affects how many shares each option covers and the stated per-share exercise price.