Cidara Therapeutics (CDTX) director equity canceled in Merck cash merger deal

Rhea-AI Filing Summary

Cidara Therapeutics director Bonnie L. Bassler reported the cash-out of her remaining equity as Cidara was acquired by Merck. On January 7, 2026, a Merck subsidiary completed a tender offer and merger in which each Cidara common share was converted into the right to receive $221.50 in cash and each Series A preferred share into $15,505.00 in cash, both without interest and subject to withholding taxes. Bassler disposed of 15 common shares at $221.50 per share and all reported stock options were canceled at the merger’s effective time in exchange for cash based on the spread between $221.50 and each option’s exercise price. All amounts reflect a 1-for-20 reverse stock split completed 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^*

Bassler Bonnie L

(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
Common Stock	01/07/2026		D(1)(2)(3)		15(4)	D	$221.5	0	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
Stock Option (right to buy)	$50.2(5)	01/07/2026		D			1,750(5)	(6)	01/21/2031	Common Stock	1,750	(6)	0	D
Stock Option (right to buy)	$38.4(5)	01/07/2026		D			875(5)	(6)	06/22/2031	Common Stock	875	(6)	0	D
Stock Option (right to buy)	$10.6(5)	01/07/2026		D			1,400(5)	(6)	06/21/2032	Common Stock	1,400	(6)	0	D
Stock Option (right to buy)	$23.4(5)	01/07/2026		D			2,125(5)	(6)	06/21/2033	Common Stock	2,125	(6)	0	D
Stock Option (right to buy)	$12.64	01/07/2026		D			2,125	(6)	07/17/2034	Common Stock	2,125	(6)	0	D
Stock Option (right to buy)	$22.81	01/07/2026		D			16,000	(6)	12/16/2034	Common Stock	16,000	(6)	0	D
Stock Option (right to buy)	$21.31	01/07/2026		D			11,100	(6)	06/17/2035	Common Stock	11,100	(6)	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 (each, a "Series A 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"). [continues to Footnote 2]

2. [continues from Footnote 1] Pursuant to the terms of the Merger Agreement, Common Shares and Series A Shares were tendered and disposed of at the Offer Acceptance Time (as defined in the Merger Agreement) in exchange for the right to receive (i) $221.50 per Common Share (the "Common Share Merger Consideration"), in cash, without interest, subject to any applicable withholding of taxes, and (ii) $15,505.00 per Series A Share (the "Series A Merger Consideration"), in cash, without interest, subject to any applicable withholding of taxes. [continues to Footnote 3]

3. [continues from Footnote 2] At the effective time of the Merger, each issued and outstanding Common Share and Series A Share (other than Common Shares (a) held by the Issuer (or in the Issuer's treasury), Merck, Purchaser, any other direct or indirect wholly owned subsidiary of Merck or the Issuer, or by stockholders of the Issuer who have properly exercised and perfected their statutory rights of appraisal, or (b) irrevocably accepted for purchase in the tender offer) was automatically canceled and converted into the right to receive the Common Share Merger Consideration and the Series A Merger Consideration, respectively, without interest and subject to any applicable withholding of taxes.

4. 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.

5. 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.

6. 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
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FAQ

What insider transaction did Cidara Therapeutics (CDTX) report for Bonnie L. Bassler?

The filing shows director Bonnie L. Bassler disposed of 15 shares of Cidara common stock at $221.50 per share and that all of her reported stock options were canceled in connection with the company’s merger with Merck in exchange for cash.

What did Cidara common shareholders receive in the Merck transaction?

Each Cidara common share was converted into the right to receive $221.50 in cash, without interest and subject to any applicable withholding of taxes, under the merger agreement with Merck.

How were Cidara Series A preferred shares treated in the merger with Merck?

Each outstanding Series A Convertible Voting Preferred Share was converted into the right to receive $15,505.00 in cash, without interest and subject to any applicable withholding of taxes.

What happened to Cidara stock options held by the reporting person in this Form 4?

Immediately prior to the merger’s effective time, each outstanding Cidara stock option became fully vested and exercisable and, to the extent unexercised, was canceled and converted into the right to receive cash equal to the number of underlying shares multiplied by $221.50 minus the exercise price per share.

Did the Cidara reverse stock split affect the numbers in this Form 4?

Yes. The filing states that the number of securities and the exercise prices reported have been adjusted to reflect Cidara’s 1-for-20 reverse stock split effected on April 24, 2024.

What is Cidara Therapeutics’ relationship to Merck after the transaction?

Following the tender offer and merger, Cidara Therapeutics continues as the surviving corporation and is now a wholly owned subsidiary of Merck.