# EDGAR Filing Document

**Accession Number:** 0001567045
**File Stem:** 0001193125-26-010790
**Filing Date:** 2026-1
**Character Count:** 9061
**Document Hash:** cf2b10c1996e6d9feb05163ad63126d1
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001193125-26-010790.hdr.sgml**: 20260112

**ACCESSION NUMBER**: 0001193125-26-010790

**CONFORMED SUBMISSION TYPE**: 4

**PUBLIC DOCUMENT COUNT**: 1

**CONFORMED PERIOD OF REPORT**: 20260112

**FILED AS OF DATE**: 20260112

**DATE AS OF CHANGE**: 20260112

**REPORTING-OWNER**: 

**OWNER DATA:**
- **COMPANY CONFORMED NAME:** Galbraith Kenneth
- **CENTRAL INDEX KEY:** 0001567045

**ORGANIZATION NAME:**

**FILING VALUES:**
- **FORM TYPE:** 4
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-41535
- **FILM NUMBER:** 26528102

**MAIL ADDRESS:**
- **STREET 1:** OCEAN PARK RPO PO BOX 45025
- **STREET 2:** 12851 16TH AVE
- **CITY:** SURREY
- **STATE:** A1
- **ZIP:** V4A9L1
**ISSUER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** Zymeworks Inc.
- **CENTRAL INDEX KEY:** 0001937653
- **STANDARD INDUSTRIAL CLASSIFICATION:** PHARMACEUTICAL PREPARATIONS [2834]
- **ORGANIZATION NAME:** 03 Life Sciences
- **EIN:** 883099146
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 1231

**BUSINESS ADDRESS:**
- **STREET 1:** 108 PATRIOT DRIVE, SUITE A
- **CITY:** MIDDLETOWN
- **STATE:** DE
- **ZIP:** 19709
- **BUSINESS PHONE:** 302-274-8744

**MAIL ADDRESS:**
- **STREET 1:** 108 PATRIOT DRIVE, SUITE A
- **CITY:** MIDDLETOWN
- **STATE:** DE
- **ZIP:** 19709

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** Zymeworks Delaware Inc.
- **DATE OF NAME CHANGE:** 20220712

### 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>Galbraith Kenneth<br><sub>(Last) (First) (Middle)</sub><br>C/O ZYMEWORKS INC.<br>108 PATRIOT DRIVE, SUITE A<br><sub>(Street)</sub><br>MIDDLETOWN, DE 19709<br><sub>(City) (State) (Zip)</sub> | **3. Date of Earliest Transaction (Month/Day/Year)**<br>2026-01-12 | **5. Relationship of Reporting Person(s) to Issuer**<br>(Check all applicable)<br>[X] Director [ ] 10% Owner<br>[X] Officer (give title below) [ ] Other (specify below)<br>_Chair & CEO_ |
| **2. Issuer Name and Ticker or Trading Symbol**<br>Zymeworks Inc. [ ZYME ] | **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 | 2026-01-12 |  | M |  | 64000 | A | 0.00<sup>(1)</sup> | 257266 | D |  |
| Common Stock | 2026-01-12 |  | S<sup>(2)</sup> |  | 30424 | D | 22.6735<sup>(3)</sup> | 226842 | 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 |
| Restricted Stock Unit | <sup>(4)</sup> | 2026-01-12 |  | M |  |  | 64000 | <sup>(5)</sup> | <sup>(5)</sup> | Common Stock | 64000 | $0.00 | 128000 | D |  |
| Stock Option (Right to Buy) | $23.16 | 2026-01-12 |  | A |  | 216000 |  | <sup>(6)</sup> | 2036-01-11 | Common Stock | 216000 | $0.00 | 216000 | D |  |
| Restricted Stock Unit | <sup>(4)</sup> | 2026-01-12 |  | A |  | 144000 |  | <sup>(7)</sup> | <sup>(7)</sup> | Common Stock | 144000 | $0.00 | 144000 | D |  |
| Performance Stock Unit | <sup>(8)(9)</sup> | 2026-01-12 |  | A |  | 222000 |  | <sup>(8)(9)</sup> | <sup>(8)(9)</sup> | Common Stock | 222000 | $0.00 | 222000 | D |  |

---

### Footnotes:

(1) Represents shares of common stock issued upon vesting of one third of the restricted stock units ("RSUs") granted on January 10, 2025.

(2) Represents shares of common stock sold to cover tax withholding obligations and other applicable fees in connection with the vesting of RSUs pursuant to mandatory "sell to cover" provisions contained in the Reporting Person's applicable RSU grant agreement, and does not represent a discretionary sale by the Reporting Person. The Reporting Person did not sell or otherwise dispose of any of the shares reported on this Form 4 for any reason other than to cover required taxes and fees.

(3) The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $22.49 to $23.05, inclusive. Upon request by the Commission staff, the Issuer, or a security holder of the Issuer, the Reporting Person will provide full information regarding the number of shares sold at each separate price.

(4) Each RSU represents the contingent right to receive, upon vesting of the RSU, one share of common stock.

(5) The RSUs were granted on January 10, 2025 and vest in three equal annual installments beginning on the first anniversary of grant date.

(6) Stock options vest as follows: (i) 25% of underlying shares of common stock on first anniversary of grant date and (ii) remainder of underlying shares of common stock in 36 equal monthly installments on last day of month following first anniversary of grant date.

(7) RSUs vest in four equal annual installments beginning on first anniversary of grant date.

(8) Each performance restricted stock unit ("PSU") represents a contingent right to receive one share of common stock. The amount reported is the maximum number of PSUs that may be earned upon achievement of certain cumulative total shareholder return ("TSR") goals over a three-year performance period ending on January 12, 2029 (or in some cases at earlier times). Between 50% and 200% of the target number of 111,000 PSUs ("Target Number") may be earned upon achievement of such TSR goals. 50% of the Target Number may be earned upon achievement of relative TSR goals if the Company's TSR for the performance period equals or exceeds a prespecified percentile for the Nasdaq Biotech Index. The PSUs will only vest at the end of the three-year performance period if the reporting person's service to the Company continues through such time that the board of directors of the Company certifies the achievement of TSR goals,

(9) (Continued from footnote 8) except in certain limited cases (such as if service to the Company is terminated by the Company without cause or in case of a change of control).

**Signature:** /s/ Daniel Dex, Attorney-in-Fact  
**Date:** 2026-01-12

### 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.**