# EDGAR Filing Document

**Accession Number:** 0002075320
**File Stem:** 0001213900-26-009664
**Filing Date:** 2026-1
**Character Count:** 11357
**Document Hash:** 36c8c6c9aa205b79cb2467c79dcd3556
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001213900-26-009664.hdr.sgml**: 20260129

**ACCESSION NUMBER**: 0001213900-26-009664

**CONFORMED SUBMISSION TYPE**: 3

**PUBLIC DOCUMENT COUNT**: 2

**CONFORMED PERIOD OF REPORT**: 20260129

**FILED AS OF DATE**: 20260129

**DATE AS OF CHANGE**: 20260129

**REPORTING-OWNER**: 

**OWNER DATA:**
- **COMPANY CONFORMED NAME:** Yang Alex Keun Mo
- **CENTRAL INDEX KEY:** 0002103399

**ORGANIZATION NAME:**

**FILING VALUES:**
- **FORM TYPE:** 3
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-43080
- **FILM NUMBER:** 26579635

**MAIL ADDRESS:**
- **STREET 1:** SOUTH TOWER
- **STREET 2:** 140 E RIDGEWOOD AVENUE, SUITE 415
- **CITY:** PARAMUS
- **STATE:** NJ
- **ZIP:** 07652
**REPORTING-OWNER**: 

**OWNER DATA:**
- **COMPANY CONFORMED NAME:** Mstone Partners Healthcare Ltd
- **CENTRAL INDEX KEY:** 0002104809

**ORGANIZATION NAME:**
- **STATE OF INCORPORATION:** K3
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** 3
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-43080
- **FILM NUMBER:** 26579634

**BUSINESS ADDRESS:**
- **ADDRESS IS A NON US LOCATION:** YES
- **STREET 1:** 7/F 80 GLOUCESTER ROAD
- **CITY:** WANCHAI
- **PROVINCE COUNTRY:** K3
- **ZIP:** 00000
- **BUSINESS PHONE:** 852 2155 9599

**MAIL ADDRESS:**
- **ADDRESS IS A NON US LOCATION:** YES
- **STREET 1:** 7/F 80 GLOUCESTER ROAD
- **CITY:** WANCHAI
- **PROVINCE COUNTRY:** K3
- **ZIP:** 00000
**ISSUER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** Polaryx Therapeutics, Inc.
- **CENTRAL INDEX KEY:** 0002075320
- **STANDARD INDUSTRIAL CLASSIFICATION:** PHARMACEUTICAL PREPARATIONS [2834]
- **ORGANIZATION NAME:** 03 Life Sciences
- **EIN:** 000000000
- **STATE OF INCORPORATION:** WY
- **FISCAL YEAR END:** 1231

**BUSINESS ADDRESS:**
- **STREET 1:** 140 EAST RIDGEWOOD AVENUE
- **STREET 2:** SUITE 415, SOUTH TOWER
- **CITY:** PARAMUS
- **STATE:** NJ
- **ZIP:** 07652
- **BUSINESS PHONE:** 201-940-7236

**MAIL ADDRESS:**
- **STREET 1:** SOUTH TOWER, 140 E RIDGEWOOD AVENUE
- **STREET 2:** SUITE 415
- **CITY:** PARAMUS
- **STATE:** NJ
- **ZIP:** 07652

## Ex-24

**Exhibit 24**

**POWER OF ATTORNEY**

Know all by these presents that the undersigned hereby constitutes and appoints each of Alex Yang, G. Michael Landis and Valerie Yeung, and any of their substitutes, signing singly, as the undersigned's true and lawful attorney-in-fact to:

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;1. execute for and on behalf of the undersigned, in the undersigned's
capacity as a director and/or officer of Polaryx Therapeutics, Inc. (the "Company"), Forms 3, 4, and 5 in accordance with
Section 16(a) of the Securities Exchange Act of 1934, as amended, and the rules thereunder;

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;2. do and perform any and all acts for and on behalf of the undersigned
which may be necessary or desirable to complete and execute any such Form 3, 4, or 5, complete and execute any amendment or amendments
thereto, and timely file such form with the U.S. Securities and Exchange Commission and any securities exchange or similar authority;
and

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;3. take any other action of any type whatsoever in connection
with the foregoing which, in the opinion of such attorney-in-fact, may be of benefit to, in the best interest of, or legally required
by, the undersigned, it being understood that the documents executed by such attorney-in-fact on behalf of the undersigned pursuant to
this Power of Attorney shall be in such form and shall contain such terms and conditions as such attorney-in-fact may approve in such
attorney-in-fact's discretion.

The undersigned hereby grants to each such attorney-in-fact full power and authority to do and perform any and every act and thing whatsoever requisite, necessary, or proper to be done in the exercise of any of the rights and powers herein granted, as fully to all intents and purposes as the undersigned might or could do if personally present, with full power of substitution or revocation, hereby ratifying and confirming all that each such attorney-in-fact, or such attorney-in-fact's substitute or substitutes, shall lawfully do or cause to be done by virtue of this Power of Attorney and the rights and powers herein granted. The undersigned also ratifies hereby any action previously taken by each such attorney-in-fact that would have been authorized by this Power of Attorney if it had been in effect at the time such action was taken. The undersigned acknowledges that each attorney-in-fact, in serving in such capacity at the request of the undersigned, is not assuming, nor is the Company assuming, any of the undersigned's responsibilities to comply with Section 16 of the Securities Exchange Act of 1934, as amended.

This Power of Attorney shall remain in full force and effect until the earliest of: (a) the undersigned is no longer required to file Forms 3, 4, and 5 with respect to the undersigned's holdings of and transactions in securities issued by the Company, (b) revocation by the undersigned in a signed writing delivered to the foregoing attorneys-in-fact, or (c) as to any attorney-in-fact, individually, until such attorney-in-fact is no longer employed by the Company or its subsidiaries or Gibson, Dunn & Crutcher LLP, as applicable.

IN WITNESS WHEREOF, the undersigned has caused this Power of Attorney to be executed as of November 27, 2025.

---

| |
|:---|
| /s/ Alex Keun Mo Yang |
| Alex Keun Mo Yang |

---

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

## FORM 3

### INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES

[ ] Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

---

| | | |
|:---|:---|:---|
| **1. Name and Address of Reporting Person**<sup>*</sup><br>Yang Alex Keun Mo<br><sub>(Last) (First) (Middle)</sub><br>SOUTH TOWER, 140 E RIDGEWOOD AVENUE,<br>SUITE 415<br><sub>(Street)</sub><br>PARAMUS, NJ 07652<br><sub>(City) (State) (Zip)</sub> | **3. Issuer Name and Ticker or Trading Symbol**<br>Polaryx Therapeutics, Inc. [ PLYX ] | **5. If Amendment, Date of Original Filed (Month/Day/Year)**<br>  |
| **2. Date of Event Requiring Statement (Month/Day/Year)**<br>2026-01-29 | **4. Relationship of Reporting Person(s) to Issuer**<br>(Check all applicable)<br>[X] Director   [X] 10% Owner<br>[X] Officer (give title below)   [ ] Other (specify below)<br>_Chief Executive Officer_ | **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>Mstone Partners Healthcare Ltd<br><sub>(Last) (First) (Middle)</sub><br>7/F, 80 GLOUCESTER ROAD<br><sub>(Street)</sub><br>WANCHAI, K3 <br><sub>(City) (State) (Zip)</sub> | **3. Issuer Name and Ticker or Trading Symbol**<br>Polaryx Therapeutics, Inc. [ PLYX ] | **5. If Amendment, Date of Original Filed (Month/Day/Year)**<br>  |
| **2. Date of Event Requiring Statement (Month/Day/Year)**<br>2026-01-29 | **4. 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>_ _ | **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 Beneficially Owned

---

|  |  |  |  |
| --- | --- | --- | --- |
| 1. Title of Security | 2. Amount of Securities Beneficially Owned | 3. Ownership Form | 4. Nature of Indirect Beneficial Ownership |
| Common Stock | 1400000<sup>(1)</sup> | D |  |
| Common Stock | 22452954 | I | By Mstone Partners Healthcare Limited<sup>(2)</sup> |
| Common Stock | 183560 | I | By MBstone Biotech Flagship Limited<sup>(3)</sup> |
| Common Stock | 108282 | I | By Mstone Pediaorphan Singapore I Pte. Limited<sup>(4)</sup> |

---

## Table II - Derivative Securities Beneficially Owned

---

|  |  |  |  |  |  |  |  |
| --- | --- | --- | --- | --- | --- | --- | --- |
| 1. Title of Derivative Security | 2. Date Exercisable and Expiration Date (Month/Day/Year) | 2. Date Exercisable and Expiration Date (Month/Day/Year) | 3. Title and Amount of Underlying Securities | 3. Title and Amount of Underlying Securities | 4. Conversion or Exercise Price | 5. Ownership Form | 6. Nature of Indirect Beneficial Ownership |
| 1. Title of Derivative Security | Date Exercisable | Expiration Date | Title | Amount or Number of Shares | 4. Conversion or Exercise Price | 5. Ownership Form | 6. Nature of Indirect Beneficial Ownership |
|  |  |  |  |  |  |  |  |

---

### Footnotes:

(1) Includes (i) 148,500 restricted stock units ("RSUs"), which will vest on March 1, 2026, (ii) 330,000 RSUs, which will vest in two equal installments on November 1, 2026 and November 1, 2027 and (iii) 450,000 RSUs, which will vest in four equal installments on September 1, 2026, September 1, 2027, September 1, 2028 and September 1, 2029, in each case subject to the Reporting Person's continued service to the Issuer or its subsidiaries, Mstone Partners Healthcare Limited ("Mstone") or its affiliates, or Curestone Partners Platform Limited or its affiliates. The RSUs are not deliverable unless and until the Issuer consummates a change in control within seven years of the grant date of such RSUs.

(2) Alex Keun Mo Yang is the founder and Chief Executive Officer of Mstone. Mr. Yang disclaims beneficial ownership over any of the reported securities, except to the extent of his pecuniary interest therein.

(3) Mr. Yang is the Chief Executive Officer of MBstone Biotech Flagship Limited. Mr. Yang disclaims beneficial ownership over any of the reported securities, except to the extent of his pecuniary interest therein.

(4) Mr. Yang is the Chief Executive Officer of Mstone Pediaorphan Singapore I Pte. Limited. Mr. Yang disclaims beneficial ownership over any of the reported securities owned, except to the extent of his pecuniary interest therein.

**Remarks:**
Exhibit 24 - Power of Attorney

Mstone, MBstone Biotech Flagship Limited and Mstone Pediaorphan Singapore I Pte. Limited may each be deemed a director by deputization of the Issuer by virtue of the fact that Mr. Yang serves on the board of directors of the Issuer and is the Chief Executive Officer of each of the entities.

**Signature:** /s/ Alex Keun Mo Yang  
**Date:** 2026-01-29

**Signature:** /s/ Alex Keun Mo Yang, Chief Executive Officer of Mstone Partners Healthcare Limited  
**Date:** 2026-01-29

### 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.**