# EDGAR Filing Document

**Accession Number:** 0001315082
**File Stem:** 0001231919-26-000031
**Filing Date:** 2026-1
**Character Count:** 17007
**Document Hash:** 7957a6b398d977bded4cf45ec5052c83
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001231919-26-000031.hdr.sgml**: 20260109

**ACCESSION NUMBER**: 0001231919-26-000031

**CONFORMED SUBMISSION TYPE**: 4

**PUBLIC DOCUMENT COUNT**: 1

**CONFORMED PERIOD OF REPORT**: 20260107

**FILED AS OF DATE**: 20260109

**DATE AS OF CHANGE**: 20260109

**REPORTING-OWNER**: 

**OWNER DATA:**
- **COMPANY CONFORMED NAME:** RA Capital Healthcare Fund LP
- **CENTRAL INDEX KEY:** 0001315082

**ORGANIZATION NAME:**
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** 4
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-36912
- **FILM NUMBER:** 26523934

**BUSINESS ADDRESS:**
- **STREET 1:** 200 BERKELEY STREET
- **STREET 2:** 18TH FLOOR
- **CITY:** BOSTON
- **STATE:** MA
- **ZIP:** 02116
- **BUSINESS PHONE:** 6177782500

**MAIL ADDRESS:**
- **STREET 1:** 200 BERKELEY STREET
- **STREET 2:** 18TH FLOOR
- **CITY:** BOSTON
- **STATE:** MA
- **ZIP:** 02116

**FORMER NAME:**
- **FORMER CONFORMED NAME:** RA Capital Biotech Fund LP
- **DATE OF NAME CHANGE:** 20050121
**REPORTING-OWNER**: 

**OWNER DATA:**
- **COMPANY CONFORMED NAME:** RA CAPITAL MANAGEMENT, L.P.
- **CENTRAL INDEX KEY:** 0001346824

**ORGANIZATION NAME:**
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** 4
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-36912
- **FILM NUMBER:** 26523935

**BUSINESS ADDRESS:**
- **STREET 1:** 200 BERKELEY STREET, 18TH FLOOR
- **CITY:** BOSTON
- **STATE:** MA
- **ZIP:** 02116
- **BUSINESS PHONE:** 617-778-2500

**MAIL ADDRESS:**
- **STREET 1:** 200 BERKELEY STREET, 18TH FLOOR
- **CITY:** BOSTON
- **STATE:** MA
- **ZIP:** 02116

**FORMER NAME:**
- **FORMER CONFORMED NAME:** RA CAPITAL MANAGEMENT, LLC
- **DATE OF NAME CHANGE:** 20051213
**REPORTING-OWNER**: 

**OWNER DATA:**
- **COMPANY CONFORMED NAME:** Shah Rajeev M.
- **CENTRAL INDEX KEY:** 0001619841

**ORGANIZATION NAME:**

**FILING VALUES:**
- **FORM TYPE:** 4
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-36912
- **FILM NUMBER:** 26523932

**MAIL ADDRESS:**
- **STREET 1:** 200 BERKELEY STREET
- **STREET 2:** 18TH FLOOR
- **CITY:** BOSTON
- **STATE:** MA
- **ZIP:** 02116
**REPORTING-OWNER**: 

**OWNER DATA:**
- **COMPANY CONFORMED NAME:** Kolchinsky Peter
- **CENTRAL INDEX KEY:** 0001384859

**ORGANIZATION NAME:**

**FILING VALUES:**
- **FORM TYPE:** 4
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-36912
- **FILM NUMBER:** 26523933

**MAIL ADDRESS:**
- **STREET 1:** 200 BERKELEY STREET
- **STREET 2:** 18TH FLOOR
- **CITY:** BOSTON
- **STATE:** MA
- **ZIP:** 02116
**ISSUER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** Cidara Therapeutics, Inc.
- **CENTRAL INDEX KEY:** 0001610618
- **STANDARD INDUSTRIAL CLASSIFICATION:** BIOLOGICAL PRODUCTS (NO DIAGNOSTIC SUBSTANCES) [2836]
- **ORGANIZATION NAME:** 03 Life Sciences
- **EIN:** 461537286
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 1231

**BUSINESS ADDRESS:**
- **STREET 1:** 6310 NANCY RIDGE DRIVE
- **STREET 2:** SUITE 101
- **CITY:** SAN DIEGO
- **STATE:** CA
- **ZIP:** 92121
- **BUSINESS PHONE:** 858-752-6170

**MAIL ADDRESS:**
- **STREET 1:** 6310 NANCY RIDGE DRIVE
- **STREET 2:** SUITE 101
- **CITY:** SAN DIEGO
- **STATE:** CA
- **ZIP:** 92121

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** K2 THERAPEUTICS, INC.
- **DATE OF NAME CHANGE:** 20140611

### UNITED STATES SECURITIES AND EXCHANGE COMMISSION
**Washington, D.C. 20549**

## FORM 4

### STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

[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**<sup>*</sup><br>RA CAPITAL MANAGEMENT, L.P.<br><sub>(Last) (First) (Middle)</sub><br>200 BERKELEY STREET, 18TH FLOOR<br><sub>(Street)</sub><br>BOSTON, MA 02116<br><sub>(City) (State) (Zip)</sub> | **3. Date of Earliest Transaction (Month/Day/Year)**<br>2026-01-07 | **5. Relationship of Reporting Person(s) to Issuer**<br>(Check all applicable)<br>[X] Director [X] 10% Owner<br>[ ] Officer (give title below) [ ] Other (specify below)<br>_ _ |
| **2. Issuer Name and Ticker or Trading Symbol**<br>Cidara Therapeutics, Inc. [ CDTX ] | **4. If Amendment, Date of Original Filed (Month/Day/Year)**<br>  | **6. Individual or Joint/Group Filing (Check Applicable Line)**<br>[ ] Form filed by One Reporting Person<br>[X] Form filed by More than One Reporting Person |

---

---

| | | |
|:---|:---|:---|
| **1. Name and Address of Reporting Person**<sup>*</sup><br>RA Capital Healthcare Fund LP<br><sub>(Last) (First) (Middle)</sub><br>200 BERKELEY STREET, 18TH FLOOR<br><sub>(Street)</sub><br>BOSTON, MA 02116<br><sub>(City) (State) (Zip)</sub> | **3. Date of Earliest Transaction (Month/Day/Year)**<br>2026-01-07 | **5. Relationship of Reporting Person(s) to Issuer**<br>(Check all applicable)<br>[X] Director [X] 10% Owner<br>[ ] Officer (give title below) [ ] Other (specify below)<br>_ _ |
| **2. Issuer Name and Ticker or Trading Symbol**<br>Cidara Therapeutics, Inc. [ CDTX ] | **4. If Amendment, Date of Original Filed (Month/Day/Year)**<br>  | **6. Individual or Joint/Group Filing (Check Applicable Line)**<br>[ ] Form filed by One Reporting Person<br>[X] Form filed by More than One Reporting Person |

---

---

| | | |
|:---|:---|:---|
| **1. Name and Address of Reporting Person**<sup>*</sup><br>Kolchinsky Peter<br><sub>(Last) (First) (Middle)</sub><br>C/O RA CAPITAL MANAGEMENT, L.P.<br>200 BERKELEY STREET, 18TH FLOOR<br><sub>(Street)</sub><br>BOSTON, MA 02116<br><sub>(City) (State) (Zip)</sub> | **3. Date of Earliest Transaction (Month/Day/Year)**<br>2026-01-07 | **5. Relationship of Reporting Person(s) to Issuer**<br>(Check all applicable)<br>[X] Director [X] 10% Owner<br>[ ] Officer (give title below) [ ] Other (specify below)<br>_ _ |
| **2. Issuer Name and Ticker or Trading Symbol**<br>Cidara Therapeutics, Inc. [ CDTX ] | **4. If Amendment, Date of Original Filed (Month/Day/Year)**<br>  | **6. Individual or Joint/Group Filing (Check Applicable Line)**<br>[ ] Form filed by One Reporting Person<br>[X] Form filed by More than One Reporting Person |

---

---

| | | |
|:---|:---|:---|
| **1. Name and Address of Reporting Person**<sup>*</sup><br>Shah Rajeev M.<br><sub>(Last) (First) (Middle)</sub><br>C/O RA CAPITAL MANAGEMENT, L.P.<br>200 BERKELEY STREET, 18TH FLOOR<br><sub>(Street)</sub><br>BOSTON, MA 02116<br><sub>(City) (State) (Zip)</sub> | **3. Date of Earliest Transaction (Month/Day/Year)**<br>2026-01-07 | **5. Relationship of Reporting Person(s) to Issuer**<br>(Check all applicable)<br>[X] Director [X] 10% Owner<br>[ ] Officer (give title below) [ ] Other (specify below)<br>_ _ |
| **2. Issuer Name and Ticker or Trading Symbol**<br>Cidara Therapeutics, Inc. [ CDTX ] | **4. If Amendment, Date of Original Filed (Month/Day/Year)**<br>  | **6. Individual or Joint/Group Filing (Check Applicable Line)**<br>[ ] Form filed by One Reporting Person<br>[X] Form filed by More than One Reporting Person |

---

## Table I - Non-Derivative Securities

---

|  |  |  |  |  |  |  |  |  |  |  |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1. Title of Security | 2. Transaction Date | 2A. Deemed Execution Date | 3. Transaction Code (V) | 3. Transaction Code (V) | 4. Securities Acquired (A) or Disposed of (D) | 4. Securities Acquired (A) or Disposed of (D) | 4. Securities Acquired (A) or Disposed of (D) | 5. Amount of Securities Beneficially Owned | 6. Ownership Form | 7. Nature of Indirect Beneficial Ownership |
| 1. Title of Security | 2. Transaction Date | 2A. Deemed Execution Date | Code | V | Amount | (A) or (D) | Price | 5. Amount of Securities Beneficially Owned | 6. Ownership Form | 7. Nature of Indirect Beneficial Ownership |
| Common Stock | 2026-01-07 |  | M<sup>(1)</sup> |  | 1286786 | A | $0.0001 | 4652309 | I | See footnotes<sup>(2)(3)</sup> |
| Common Stock | 2026-01-07 |  | D<sup>(4)(5)(6)</sup> |  | 4652309 | D | $221.50 | 0 | I | See footnotes<sup>(2)(3)</sup> |

---

## Table II - Derivative Securities

---

|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1. Title of Derivative Security | 2. Conversion or Exercise Price | 3. Transaction Date | 3A. Deemed Execution Date | 4. Transaction Code (V) | 4. Transaction Code (V) | 5. Number of Derivative Securities Acquired (A) or Disposed of (D) | 5. Number of Derivative Securities Acquired (A) or Disposed of (D) | 6. Date Exercisable and Expiration Date | 6. Date Exercisable and Expiration Date | 7. Title and Amount of Underlying Securities | 7. Title and Amount of Underlying Securities | 8. Price of Derivative Security | 9. Number of Derivative Securities Beneficially Owned | 10. Ownership Form | 11. Nature of Indirect Beneficial Ownership |
| 1. Title of Derivative Security | 2. Conversion or Exercise Price | 3. Transaction Date | 3A. Deemed Execution Date | Code | V | (A) | (D) | Date Exercisable | Expiration Date | Title | Amount or Number of Shares | 8. Price of Derivative Security | 9. Number of Derivative Securities Beneficially Owned | 10. Ownership Form | 11. Nature of Indirect Beneficial Ownership |
| Stock Option (right to buy) | $26.62 | 2026-01-07 |  | D |  |  | 22200 | <sup>(7)</sup> | 2035-01-02 | Common Stock | 22200 | <sup>(7)</sup> | 0 | I | See footnotes<sup>(2)(8)</sup> |
| Stock Option (right to buy) | $21.31 | 2026-01-07 |  | D |  |  | 5079 | <sup>(7)</sup> | 2035-06-17 | Common Stock | 5079 | <sup>(7)</sup> | 0 | I | See Footnotes<sup>(2)(8)</sup> |
| Pre-Funded Warrants (Right to Buy) | $0.0001 | 2026-01-07 |  | M<sup>(1)</sup> |  |  | 1286786 | <sup>(9)</sup> | <sup>(9)</sup> | Common Stock | 1286786 | <sup>(7)</sup> | 0 | I | See footnotes<sup>(2)(3)</sup> |
| Series A Preferred Stock | <sup>(10)</sup> | 2026-01-07 |  | D<sup>(4)(5)(6)</sup> |  |  | 89956 | <sup>(7)</sup> | <sup>(10)</sup> | Common Stock | 6296920 | $15505 | 0 | I | See footnotes<sup>(2)(3)</sup> |

---

### Footnotes:

(1) Pursuant to the Merger Agreement (as defined below), Pre-Funded Warrants that were outstanding and unexercised as of immediately prior the effective time of the Merger (as defined below) were treated as being simultaneously cashless exercised in accordance with their terms, subject to any applicable withholding of taxes.

(2) RA Capital Management, L.P. (the "Adviser") is the investment manager for RA Capital Healthcare Fund, L.P. (the "Fund"). The general partner of the Adviser is RA Capital Management GP, LLC (the "Adviser GP"), of which Dr. Peter Kolchinsky and Mr. Rajeev Shah are the managing members. Each of the Adviser, the Adviser GP, Dr. Kolchinsky, and Mr. Shah disclaims beneficial ownership of any of the reported securities, except to the extent of its or his respective pecuniary interest therein.

(3) Held directly by the Fund.

(4) 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").

(5) (Continued from Footnote 4) 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.

(6) (Continued from Footnote 5) 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.

(7) 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.

(8) Joshua Resnick is a Partner of the Adviser who serves on the Issuer's board of directors. Under Dr. Resnick's arrangement with the Adviser, Dr. Resnick holds the option for the benefit of the Fund. Dr. Resnick 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 Persons therefore disclaim beneficial ownership of the option and underlying common stock.

(9) The Pre-Funded Warrants had no expiration date and were exercisable immediately. Notwithstanding the foregoing, the Reporting Persons were not entitled to exercise the Pre-Funded Warrants to the extent that such exercise would cause the aggregate number of Common Shares beneficially owned by the Reporting Persons, their affiliates and any persons who are members of a Section 13(d) group with the Reporting Persons or their affiliates to exceed 9.99% of the total number of issued and outstanding Common Shares of the Issuer following such exercise.

(10) Each share of Series A Preferred Stock was convertible at any time at the option of the holder into a number of shares of common stock equal to the quotient of (A) $1,000, plus all declared and unpaid dividends, divided by (B) the Conversion Price of $14.20 per share of common stock, subject to appropriate adjustment in the event of any stock dividend, stock split, combination or other similar recapitalization, rounded down to the nearest whole share of common stock, for no additional consideration; except that the holder did not have the right to convert any portion of the Series A Preferred Stock such that the holder would beneficially own in excess of 9.99% of the shares of common stock outstanding immediately after giving effect to such conversion. The Series A Preferred Stock had no expiration date.

**Remarks:**
Joshua Resnick, a Partner of the Adviser, serves on the Issuer's board of directors.

**Signature:** /s/ Peter Kolchinsky, Manager of RA Capital Management, L.P.  
**Date:** 2026-01-09

**Signature:** /s/ Peter Kolchinsky, Manager of RA Capital Healthcare Fund GP, LLC the General Partner of RA Capital Healthcare Fund, L.P.  
**Date:** 2026-01-09

**Signature:** /s/ Peter Kolchinsky, individually  
**Date:** 2026-01-09

**Signature:** /s/ Rajeev Shah, individually  
**Date:** 2026-01-09

### Remarks:

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).

** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).

Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.

**Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.**