Merger cashes out Cidara Therapeutics (CDTX) director stock options

Rhea-AI Filing Summary

Cidara Therapeutics director Spencer Ryan reported the cash-out of his stock options in connection with Merck’s acquisition of the company. Under a Merger Agreement dated November 13, 2025 among Cidara, Merck Sharp & Dohme LLC and Caymus Purchaser, Inc., a tender offer for all outstanding common and Series A preferred shares was completed on January 7, 2026 and followed by a merger, making Cidara a wholly owned subsidiary of Merck.

Immediately before the effective time of the merger, each of Ryan’s outstanding stock options became fully vested and exercisable and, to the extent unexercised, was cancelled and converted into a right to receive cash. The cash amount equals the number of common shares subject to each option multiplied by the excess of $221.50 per share over the option’s exercise price. The Form 4 lists option grants with exercise prices of $12.63, $12.64 and $21.31 per share, all reduced to zero balance after the transaction.

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^*

Spencer Ryan

(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 Cidara Therapeutics (CDTX) report in this Form 4?

The Form 4 reports that director Spencer Ryan had his Cidara Therapeutics stock options cancelled and converted into a right to receive cash in connection with Merck’s acquisition of the company.

How were Spencer Ryan’s Cidara stock options treated in the Merck merger?

Immediately prior to the effective time of the Merger, each outstanding option became fully vested and exercisable and, if still outstanding and unexercised at that time, was cancelled and converted into a right to receive cash.

What cash amount did each Cidara stock option entitle Spencer Ryan to receive?

For each option, the cash amount equals the product of (i) the total number of common shares subject to the option and (ii) the excess of $221.50 per Common Share over the exercise price payable per share under that option.

What were the exercise prices of the Cidara options reported for Spencer Ryan?

The Form 4 lists three stock option grants with exercise prices of $12.63, $12.64, and $21.31 per share, each covering common stock of Cidara Therapeutics.

Did Spencer Ryan hold any of these Cidara options after the reported transactions?

No. After the reported transactions on January 7, 2026, the Form 4 shows 0 derivative securities beneficially owned for each of the listed stock option grants.

What corporate transaction triggered the changes to Cidara director stock options?

A tender offer and subsequent merger under the Merger Agreement dated November 13, 2025 led to Cidara Therapeutics becoming a wholly owned subsidiary of Merck Sharp & Dohme LLC, which triggered the vesting and cash-out of outstanding options.