# EDGAR Filing Document

**Accession Number:** 0001901039
**File Stem:** 0001104659-23-005033
**Filing Date:** 2023-1
**Character Count:** 10458
**Document Hash:** a9b2b6a56fee14b79eaefdaab837009c
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001104659-23-005033.hdr.sgml**: 20230119

**ACCESSION NUMBER**: 0001104659-23-005033

**CONFORMED SUBMISSION TYPE**: 4

**PUBLIC DOCUMENT COUNT**: 2

**CONFORMED PERIOD OF REPORT**: 20230117

**FILED AS OF DATE**: 20230119

**DATE AS OF CHANGE**: 20230119

**REPORTING-OWNER**: 

**OWNER DATA:**
- **COMPANY CONFORMED NAME:** Smith Susan Laura
- **CENTRAL INDEX KEY:** 0001901039

**FILING VALUES:**
- **FORM TYPE:** 4
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-38650
- **FILM NUMBER:** 23537872

**MAIL ADDRESS:**
- **STREET 1:** 5 OVERLOOK CT
- **CITY:** LAMBERTVILLE
- **STATE:** NJ
- **ZIP:** 08530
**ISSUER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** Y-mAbs Therapeutics, Inc.
- **CENTRAL INDEX KEY:** 0001722964
- **STANDARD INDUSTRIAL CLASSIFICATION:** PHARMACEUTICAL PREPARATIONS [2834]
- **IRS NUMBER:** 474619612
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 1231

**BUSINESS ADDRESS:**
- **STREET 1:** 230 PARK AVENUE
- **STREET 2:** SUITE 3350
- **CITY:** NEW YORK
- **STATE:** NY
- **ZIP:** 10169
- **BUSINESS PHONE:** 212-847-9841

**MAIL ADDRESS:**
- **STREET 1:** 230 PARK AVENUE
- **STREET 2:** SUITE 3350
- **CITY:** NEW YORK
- **STATE:** NY
- **ZIP:** 10169

## Ex-24

**Exhibit 24**

**POWER OF ATTORNEY**

(For Executing Form ID and Forms 3, 4 and 5 and Schedules 13D and 13G)

Know all by these presents, that the undersigned hereby constitutes and appoints each of Dayne Brown, Zo Khalid, and Albert Gelin of Cooley LLP, and Sune Reinholth Nyland of Y-mAbs Therapeutics, Inc. (the "***Company***"), signing individually, the undersigned's true and lawful attorneys-in fact and agents to:

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(1) Prepare, execute in the undersigned's name and on the undersigned's behalf, and submit to the the Securities and Exchange Commission (the "***SEC***") Form ID and Forms 3, 4 and 5 (including amendments thereto and joint filing agreements in connection therewith) in accordance with Section 13 or Section 16 of the Securities Exchange Act of 1934, as amended (the "***Exchange Act***") and the rules thereunder in the undersigned's capacity as a beneficial owner of a registered class of securities of the Company;

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(2) Do and perform any and all acts for and on behalf of the undersigned that may be necessary or desirable to prepare and execute any such Form ID and Forms 3, 4 or 5, Schedules 13D and 13G (including amendments thereto and joint filing agreements in connection therewith) and Forms 144, and file such forms with the SEC and any stock exchange, self-regulatory association or any similar authority; and

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(3) Take any other action of any type whatsoever in connection with the foregoing that, in the opinion of such attorney-in-fact, may be of benefit to, in the best interest of, or legally required of the undersigned, it being understood that the documents executed by the 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 the attorney-in-fact may approve in the 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 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 acknowledges that the foregoing attorneys-in-fact, and their substitutes, in serving in such capacity at the request of the undersigned, are not assuming (nor is the Company assuming) any of the undersigned's responsibilities to comply with Sections 13 and 16 of the Exchange Act and Rule 144 thereunder.

This Power of Attorney shall remain in full force and effect until the earliest to occur of (a) the undersigned is no longer required to file Form ID or Forms 3, 4 and 5 or Schedules 13D or 13G 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 Company and the foregoing attorneys-in fact or (c) as to any attorney-in-fact individually, until such attorney-in-fact is no longer employed by Cooley LLP or by the Company.

IN WITNESS WHEREOF, the undersigned has caused this Power of Attorney to be executed as of the date written below.

---

| | | |
|:---|:---|:---|
| Date: | December 5, 2022 | /s/ Susan Smith |
| | | Susan Smith |

---

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

## FORM 4

### STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

[ ] 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>Smith Susan Laura<br><sub>(Last) (First) (Middle)</sub><br>C/O Y-MABS THERAPEUTICS, INC.<br>230 PARK AVENUE SUITE 3350<br><sub>(Street)</sub><br>NEW YORK, NY 10169<br><sub>(City) (State) (Zip)</sub> | **3. Date of Earliest Transaction (Month/Day/Year)**<br>2023-01-17 | **5. Relationship of Reporting Person(s) to Issuer**<br>(Check all applicable)<br>[ ] Director [ ] 10% Owner<br>[X] Officer (give title below) [ ] Other (specify below)<br>_SVP & CHIEF COMMERCIAL OFFICER_ |
| **2. Issuer Name and Ticker or Trading Symbol**<br>Y-mAbs Therapeutics, Inc. [ YMAB ] | **4. If Amendment, Date of Original Filed (Month/Day/Year)**<br>  | **6. Individual or Joint/Group Filing (Check Applicable Line)**<br>[X] Form filed by One Reporting Person<br>[ ] 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 | 2023-01-17 |  | A |  | 17800<sup>(1)</sup> | A | $0 | 17800 | D |  |

---

## 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 |
| Employee Stock Option (right to buy)<sup>(2)</sup> | $4.70 | 2023-01-17 |  | A |  | 35700 |  | <sup>(3)</sup> | 2033-01-17 | Common stock | 35700 | $0 | 35700 | D |  |

---

### Footnotes:

(1) Represents 17,800 restricted stock units ("RSUs") granted to the Reporting Person pursuant to the 2018 Equity Incentive Plan of Y-mAbs Therapeutics, Inc. Each RSU represents a contingent right to receive one share of Common Stock on the vesting dates of the RSU. The RSUs vest by 1/3 on each of January 17, 2024, January 17, 2025 and January 17, 2026 subject to the continuing employment of the Reporting Person on each vesting date.

(2) Stock options granted to the Reporting Person pursuant to the 2018 Equity Incentive Plan of Y-mAbs Therapeutics, Inc.

(3) The stock option shall vest and become exercisable as to 25% of the shares subject to the option on January 17, 2024, and thereafter vests and become exercisable as to 1/48th of the shares in equal monthly installments, until such time as the option is 100% vested, subject to the continuing employment of the Reporting Person on each vesting.

**Remarks:**
Exhibit Index: Exhibit 24 - Power of Attorney for Susan Smith dated December 5, 2022.

**Signature:** /s/ Sune Reinholth Nyland, Attorney-in-Fact for Susan Smith  
**Date:** 2023-01-19

### 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.**