# EDGAR Filing Document

**Accession Number:** 0001509745
**File Stem:** 0001104659-23-035047
**Filing Date:** 2023-3
**Character Count:** 6878
**Document Hash:** afbcbb650990d7b83580cc5b5a621132
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001104659-23-035047.hdr.sgml**: 20230321

**ACCESSION NUMBER**: 0001104659-23-035047

**CONFORMED SUBMISSION TYPE**: 4

**PUBLIC DOCUMENT COUNT**: 1

**CONFORMED PERIOD OF REPORT**: 20230317

**FILED AS OF DATE**: 20230321

**DATE AS OF CHANGE**: 20230321

**REPORTING-OWNER**: 

**OWNER DATA:**
- **COMPANY CONFORMED NAME:** ONSI DOUGLAS E
- **CENTRAL INDEX KEY:** 0001270185

**FILING VALUES:**
- **FORM TYPE:** 4
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-37990
- **FILM NUMBER:** 23749758

**MAIL ADDRESS:**
- **STREET 1:** C/O TOLERRX INC
- **STREET 2:** 300 TECHNOLOGY SQUARE
- **CITY:** CAMBRIDGE
- **STATE:** MA
- **ZIP:** 02139
**ISSUER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** LEAP THERAPEUTICS, INC.
- **CENTRAL INDEX KEY:** 0001509745
- **STANDARD INDUSTRIAL CLASSIFICATION:** PHARMACEUTICAL PREPARATIONS [2834]
- **IRS NUMBER:** 274412575
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 1231

**BUSINESS ADDRESS:**
- **STREET 1:** 47 THORNDIKE STREET
- **STREET 2:** SUITE B1-1
- **CITY:** CAMBRIDGE
- **STATE:** MA
- **ZIP:** 02142
- **BUSINESS PHONE:** 617 252 4343

**MAIL ADDRESS:**
- **STREET 1:** 47 THORNDIKE STREET
- **STREET 2:** SUITE B1-1
- **CITY:** CAMBRIDGE
- **STATE:** MA
- **ZIP:** 02142

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** Dekkun Corp
- **DATE OF NAME CHANGE:** 20110107

### 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>ONSI DOUGLAS E<br><sub>(Last) (First) (Middle)</sub><br>C/O LEAP THERAPEUTICS, INC.<br>47 THORNDIKE STREET SUITE B1-1<br><sub>(Street)</sub><br>CAMBRIDGE, MA 02141<br><sub>(City) (State) (Zip)</sub> | **3. Date of Earliest Transaction (Month/Day/Year)**<br>2023-03-17 | **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>_CEO,CFO,Pres.,GC,Treas.,&Sec._ |
| **2. Issuer Name and Ticker or Trading Symbol**<br>LEAP THERAPEUTICS, INC. [ LPTX ] | **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 | 2023-03-17 |  | M |  | 660606 | A | <sup>(1)</sup> | 661466 | D |  |
| Common Stock |  |  |  |  |  |  |  | 4144804 | I | By HealthCare Ventures IX, L.P.<sup>(2)</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 |
| Restricted Stock Units | <sup>(1)</sup> | 2023-03-17 |  | M |  |  | 660606 | <sup>(3)</sup> | <sup>(3)</sup> | Common Stock | 660606 | $0 | 0 | D |  |

---

### Footnotes:

(1) Restricted Stock Units convert into common stock on a one-for-one basis.

(2) The reporting person is a Managing Director of HealthCare Partners IX, LLC which is the General Partner of HealthCare Partners IX, L.P., which is the General Partner of HealthCare Ventures IX, L.P. The reporting person beneficially owns and shares voting and dispositive power with respect to all of the securities owned by HealthCare Ventures IX, L.P. and disclaims beneficial ownership of these shares except to the extent of his proportionate pecuniary interest therein.

(3) On March 17, 2020, the reporting person was granted 660,606 Restricted Stock Units, vesting on March 17, 2023 or upon a change of control, whichever is earlier, provided that the grantee continues to be employed by, or provides service to the Company from the grant date to the vesting date of the Restricted Stock Units. At such time as the Restricted Stock Units vest, one share of Common Stock shall be issued automatically in settlement of each Restricted Stock Unit.

**Signature:** /s/ Douglas E. Onsi  
**Date:** 2023-03-21

### 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.**