Merck completes Cidara Therapeutics (CDTX) merger; director options cashed

Rhea-AI Filing Summary

Cidara Therapeutics director reports option cancellation tied to Merck buyout. 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 continues as a wholly owned Merck subsidiary. In connection with the merger, each outstanding stock option became fully vested and, if unexercised, was cancelled at the merger’s effective time and converted into a cash right equal to the number of underlying shares multiplied by the excess of $221.50 per share over the option’s exercise price.

The Form 4 reports that director Joshua Resnick had stock options covering 22,200 and 5,079 Cidara common shares, both reported as derivative dispositions leaving zero options outstanding. The filing notes these options are held for the benefit of RA Capital Healthcare Fund, and Resnick is required to turn over any net cash or stock to RA Capital Management, so he disclaims beneficial ownership of the options and underlying shares.

Insights

Equity compensation and M&A specialist

Merger triggers cash-out of director-held options with RA Capital structure.

The disclosure shows how Cidara’s merger with Merck affected equity awards. Upon closing on January 7, 2026, all outstanding options became fully vested and were cancelled in exchange for cash equal to the number of shares per grant times the spread between $221.50 and the option exercise price. This is a standard cash-out mechanism in an all-cash acquisition.

For director Joshua Resnick, options over 22,200 and 5,079 shares were reported as derivative dispositions, leaving no options outstanding after the merger. However, footnotes explain he holds these options for the benefit of RA Capital Healthcare Fund, L.P., with any net cash or stock applied against advisory fees owed to RA Capital Management, L.P., and he disclaims beneficial ownership. This indicates the economic interest resides with the fund structure rather than the individual, and the transactions primarily reflect completion of the agreed merger terms rather than discretionary insider trading.

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^*

Resnick Joshua

(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)	$26.62	01/07/2026		D			22,200	(1)(2)	01/02/2035	Common Stock	22,200	(1)(2)	0	D(3)
Stock Option (right to buy)	$21.31	01/07/2026		D			5,079	(1)(2)	06/17/2035	Common Stock	5,079	(1)(2)	0	D(3)

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.

3. Under the Reporting Person's arrangement with RA Capital Management, L.P. (the "Adviser"), the Reporting Person holds the option for the benefit of the RA Capital Healthcare Fund, L.P. (the "Fund"). The Reporting Person is obligated to turn over to the Adviser any net cash or stock received upon exercise of the option, which will offset advisory fees owed by the Fund to the Adviser. The Reporting Person therefore disclaims beneficial ownership of the option and underlying common stock.

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 insider transaction is reported in this Cidara (CDTX) Form 4?

The Form 4 reports that director Joshua Resnick had stock options over 22,200 and 5,079 Cidara common shares treated as derivative dispositions, leaving zero options outstanding after the merger with Merck.

How did the Merck acquisition affect Cidara (CDTX) stock options?

Pursuant to the merger, each outstanding Cidara stock option became fully vested and, if unexercised at the effective time, was cancelled and converted into a right to receive cash equal to the number of shares under the option times the excess of $221.50 per share over the option’s exercise price.

What corporate event involving Merck is described for Cidara (CDTX)?

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 continues as a wholly owned subsidiary of Merck.

Does Joshua Resnick personally own the Cidara options reported in the Form 4?

The filing states that under an arrangement with RA Capital Management, L.P., Resnick holds the options for the benefit of RA Capital Healthcare Fund, L.P., must turn over any net cash or stock to RA Capital Management, and therefore disclaims beneficial ownership of the options and underlying common stock.

What cash consideration per Cidara (CDTX) share is referenced for option payouts?

For each option, the cash right is calculated using a per-share value of $221.50 for Cidara common stock, minus the option’s exercise price, multiplied by the total number of shares subject to the option.

What is Joshua Resnick’s relationship to Cidara Therapeutics (CDTX)?

The Form 4 identifies Joshua Resnick as a director of Cidara Therapeutics, Inc. and indicates the filing is made by one reporting person.