Merck deal cashes out Cidara (NASDAQ: CDTX) director stock options

Rhea-AI Filing Summary

Cidara Therapeutics director James Merson reported the cash cancellation of stock options tied to Merck’s acquisition of Cidara. On January 7, 2026, a Merck subsidiary completed a tender offer for all outstanding Cidara common shares and Series A preferred shares and then merged into Cidara, which became a wholly owned Merck subsidiary. In connection with the merger, each of Merson’s outstanding stock options, including grants over 4,250, 2,125 and 11,100 Cidara common shares, became fully vested and exercisable and was then cancelled.

Each cancelled option was converted into the right to receive cash, without interest and subject to tax withholding, equal to the number of underlying shares multiplied by the excess of $221.50 per share over the option’s exercise price.

Insights

Equity compensation and M&A analyst

Director options are cashed out for cash spread in Merck’s Cidara buyout.

The filing shows that Cidara Therapeutics director James Merson held several stock option awards that were affected by Merck’s acquisition of Cidara. On January 7, 2026, a Merck subsidiary completed a tender offer for all outstanding Cidara common and Series A preferred shares and then merged with Cidara, which now operates as a wholly owned Merck subsidiary.

Immediately prior to the merger’s effective time, each outstanding option became fully vested and exercisable. To the extent options remained unexercised at that time, they were cancelled and converted into a cash right. The cash amount is defined as the number of underlying Cidara common shares multiplied by the excess of $221.50 per share over the option’s exercise price.

The transactions reported for options over 4,250, 2,125 and 11,100 shares are coded as "D" for disposition, with 0% of those options remaining afterward. This illustrates a typical M&A treatment where equity awards are cashed out based on the deal price, with the actual value to the director depending on each award’s exercise price.

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^*

Merson James

(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)	$12.63	01/07/2026		D			4,250	(1)(2)	04/25/2034	Common Stock	4,250	(1)(2)	0	D
Stock Option (right to buy)	$12.64	01/07/2026		D			2,125	(1)(2)	07/17/2034	Common Stock	2,125	(1)(2)	0	D
Stock Option (right to buy)	$21.31	01/07/2026		D			11,100	(1)(2)	06/17/2035	Common Stock	11,100	(1)(2)	0	D

Explanation of Responses:

1. 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").

2. 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.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
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FAQ

What does the James Merson Form 4 disclose for Cidara Therapeutics (CDTX)?

The Form 4 reports that director James Merson had Cidara stock options that became fully vested and were then cancelled for cash in connection with Merck’s acquisition of Cidara on January 7, 2026.

How were James Merson’s Cidara (CDTX) stock options treated in the Merck merger?

Immediately before the merger’s effective time, each outstanding option became fully vested and exercisable and, if still unexercised, was cancelled and converted into a cash right based on the merger price formula.

What cash formula applied to the cancelled Cidara options in this Form 4?

Each cancelled option was converted into the right to receive cash equal to the total number of underlying Common Shares multiplied by the excess of $221.50 per share over the option’s exercise price, before taxes.

How many Cidara stock options did James Merson dispose of in this filing?

The filing shows dispositions of three stock option grants covering 4,250, 2,125 and 11,100 Cidara common shares, all reported with 0 derivative securities remaining afterward.

What corporate transaction involving Cidara Therapeutics (CDTX) is referenced in the Form 4?

The Form 4 references an Agreement and Plan of Merger under which a Merck subsidiary completed a tender offer for all outstanding Cidara common and Series A preferred shares on January 7, 2026 and then merged with Cidara, making it a wholly owned Merck subsidiary.

Is James Merson’s ownership reported as direct or indirect in this Cidara Form 4?

The transactions for the stock options are reported with direct (D) ownership and no separate entity is listed in the nature of ownership field.