# EDGAR Filing Document

**Accession Number:** 0001704292
**File Stem:** 0000905148-26-001546
**Filing Date:** 2026-4
**Character Count:** 7918
**Document Hash:** 4e49f3d6bab016176aa91eb1fb2470ea
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0000905148-26-001546.hdr.sgml**: 20260403

**ACCESSION NUMBER**: 0000905148-26-001546

**CONFORMED SUBMISSION TYPE**: 4

**PUBLIC DOCUMENT COUNT**: 1

**CONFORMED PERIOD OF REPORT**: 20260304

**FILED AS OF DATE**: 20260403

**DATE AS OF CHANGE**: 20260403

**REPORTING-OWNER**: 

**OWNER DATA:**
- **COMPANY CONFORMED NAME:** Smiley Joshua L
- **CENTRAL INDEX KEY:** 0001725189

**ORGANIZATION NAME:**

**FILING VALUES:**
- **FORM TYPE:** 4
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-38205
- **FILM NUMBER:** 26839149

**MAIL ADDRESS:**
- **STREET 1:** 314 MAIN STREET
- **STREET 2:** 4TH FLOOR, SUITE 100
- **CITY:** CAMBRIDGE
- **STATE:** MA
- **ZIP:** 02142
**ISSUER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** Zai Lab Ltd
- **CENTRAL INDEX KEY:** 0001704292
- **STANDARD INDUSTRIAL CLASSIFICATION:** PHARMACEUTICAL PREPARATIONS [2834]
- **ORGANIZATION NAME:** 03 Life Sciences
- **EIN:** 000000000
- **STATE OF INCORPORATION:** E9
- **FISCAL YEAR END:** 1231

**BUSINESS ADDRESS:**
- **ADDRESS IS A NON US LOCATION:** YES
- **STREET 1:** 899 HALEI ROAD
- **STREET 2:** BUILDING B, PUDONG
- **CITY:** SHANGHAI
- **PROVINCE COUNTRY:** F4
- **BUSINESS PHONE:** 862161632588

**MAIL ADDRESS:**
- **ADDRESS IS A NON US LOCATION:** YES
- **STREET 1:** 899 HALEI ROAD
- **STREET 2:** BUILDING B, PUDONG
- **CITY:** SHANGHAI
- **PROVINCE COUNTRY:** F4

### 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>Smiley Joshua L<br><sub>(Last) (First) (Middle)</sub><br>C/O ZAI LAB LIMITED<br>314 MAIN STREET, 4TH FLOOR, SUITE 100<br><sub>(Street)</sub><br>CAMBRIDGE, MA 02142<br><sub>(City) (State) (Zip)</sub> | **3. Date of Earliest Transaction (Month/Day/Year)**<br>2026-03-04 | **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>_See Remarks_ |
| **2. Issuer Name and Ticker or Trading Symbol**<br>Zai Lab Ltd [ ZLAB ] | **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 |
| American Depositary Shares<sup>(1)</sup> | 2026-04-01 |  | M |  | 32062<sup>(2)</sup> | A | <sup>(3)</sup> | 123088 | D |  |
| American Depositary Shares<sup>(1)</sup> | 2026-04-02 |  | M |  | 7145<sup>(2)</sup> | A | <sup>(3)</sup> | 130233 | D |  |
| American Depositary Shares<sup>(1)</sup> | 2026-04-02 |  | S |  | 9614<sup>(4)</sup> | D | $20.39 | 120619 | 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 |
| Performance-Based Share Units | <sup>(5)</sup> | 2026-03-04 |  | A |  | 17887 |  | <sup>(6)</sup> | <sup>(6)</sup> | American Depositary Shares<sup>(1)</sup> | 17887 | $0 | 17887 | D |  |
| Restricted Share Units | <sup>(3)</sup> | 2026-04-01 |  | M |  |  | 32062 | <sup>(7)</sup> | <sup>(7)</sup> | American Depositary Shares<sup>(1)</sup> | 32062 | $0 | 64125 | D |  |
| Restricted Share Units | <sup>(3)</sup> | 2026-04-02 |  | M |  |  | 7145 | <sup>(8)</sup> | <sup>(8)</sup> | American Depositary Shares<sup>(1)</sup> | 7145 | $0 | 7145 | D |  |

---

### Footnotes:

(1) Each American Depositary Share ("ADS") represents ten Ordinary Shares of the issuer. Our ADSs and Ordinary Shares are fully fungible. For purposes of this Form 4, we are reporting this in terms of ADSs.

(2) ADSs acquired upon vesting of Restricted Share Units ("RSUs").

(3) Each RSU represents a contingent right to receive one ADS.

(4) These ADSs were sold automatically to cover taxes upon vesting of RSUs.

(5) Each performance-based share unit ("PSU") represents a contingent right to receive one ADS.

(6) The reporting person was granted PSUs on March 12, 2025 based on the satisfaction of specified performance criteria between January 1, 2025 through December 31, 2025. On March 4, 2026, the performance-based vesting conditions were confirmed for PSUs representing 17,887 ADSs. The PSUs vest in full on March 12, 2028, the third anniversary of the date of grant, subject to continuous service.

(7) The RSUs vest in equal annual installments over four years beginning on 04/01/2025, the first anniversary of the date of grant, subject to continuous service. Vested shares will be delivered in the form of ADSs to the reporting person following vesting.

(8) The RSUs vest in equal annual installments over four years beginning on 04/03/2024, the first anniversary of the date of grant, subject to continuous service. Vested shares will be delivered in the form of ADSs to the reporting person following vesting.

**Remarks:**
President and Chief Operating Officer

**Signature:** /s/ Bruce Blefeld, Attorney-in-Fact  
**Date:** 2026-04-03

### 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.**