# EDGAR Filing Document

**Accession Number:** 0002035832
**File Stem:** 0001193125-26-010566
**Filing Date:** 2026-1
**Character Count:** 8987
**Document Hash:** 694e11f446a1ad5a64527b7804dcef49
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001193125-26-010566.hdr.sgml**: 20260112

**ACCESSION NUMBER**: 0001193125-26-010566

**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:** Kim Helen Susan
- **CENTRAL INDEX KEY:** 0001422772

**ORGANIZATION NAME:**

**FILING VALUES:**
- **FORM TYPE:** 4
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-43047
- **FILM NUMBER:** 26527575

**MAIL ADDRESS:**
- **STREET 1:** 3832 BAY CENTER PLACE
- **CITY:** HAYWARD
- **STATE:** CA
- **ZIP:** 94545
**ISSUER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** Aktis Oncology, Inc.
- **CENTRAL INDEX KEY:** 0002035832
- **STANDARD INDUSTRIAL CLASSIFICATION:** PHARMACEUTICAL PREPARATIONS [2834]
- **ORGANIZATION NAME:** 03 Life Sciences
- **EIN:** 852584233
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 1231

**BUSINESS ADDRESS:**
- **STREET 1:** 17 DRYDOCK AVENUE
- **STREET 2:** SUITE #17-401
- **CITY:** BOSTON
- **STATE:** MA
- **ZIP:** 02210
- **BUSINESS PHONE:** 978-237-4380

**MAIL ADDRESS:**
- **STREET 1:** 17 DRYDOCK AVENUE
- **STREET 2:** SUITE #17-401
- **CITY:** BOSTON
- **STATE:** MA
- **ZIP:** 02210

### 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>Kim Helen Susan<br><sub>(Last) (First) (Middle)</sub><br>C/O AKTIS ONCOLOGY, INC.<br>17 DRYDOCK AVENUE,  SUITE 17-401<br><sub>(Street)</sub><br>BOSTON, MA 02210<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 [X] 10% Owner<br>[ ] Officer (give title below) [ ] Other (specify below)<br>_ _ |
| **2. Issuer Name and Ticker or Trading Symbol**<br>Aktis Oncology, Inc. [ AKTS ] | **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 |  | C<sup>(1)</sup> |  | 4859370 | A | <sup>(1)</sup> | 4859370 | I | See Footnote<sup>(2)</sup> |
| Common Stock | 2026-01-12 |  | P |  | 812455 | A | $18.00 | 5671825 | I | See Footnote<sup>(2)</sup> |
| Common Stock | 2026-01-12 |  | C<sup>(1)</sup> |  | 134842 | A | <sup>(1)</sup> | 134842 | I | See Footnote<sup>(3)</sup> |
| Common Stock | 2026-01-12 |  | P |  | 22545 | A | $18.00 | 157387 | I | See Footnote<sup>(3)</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 |
| Series A Redeemable Convertible Preferred Stock | <sup>(4)</sup> | 2026-01-12 |  | C |  |  | 14838250 | <sup>(4)</sup> | <sup>(4)</sup> | Common Stock | 3900284 | $0 | 0 | I | See Footnote<sup>(2)</sup> |
| Series A Redeemable Convertible Preferred Stock | <sup>(4)</sup> | 2026-01-12 |  | C |  |  | 411750 | <sup>(4)</sup> | <sup>(4)</sup> | Common Stock | 108229 | $0 | 0 | I | See Footnote<sup>(3)</sup> |
| Series B Redeemable Convertible Preferred Stock | <sup>(5)</sup> | 2026-01-12 |  | C |  |  | 3648750 | <sup>(5)</sup> | <sup>(5)</sup> | Common Stock | 959086 | $0 | 0 | I | See Footnote<sup>(2)</sup> |
| Series B Redeemable Convertible Preferred Stock | <sup>(5)</sup> | 2026-01-12 |  | C |  |  | 101250 | <sup>(5)</sup> | <sup>(5)</sup> | Common Stock | 26613 | $0 | 0 | I | See Footnote<sup>(3)</sup> |

---

### Footnotes:

(1) Represents shares of the Issuer's Common Stock received upon conversion of shares of the Series A Redeemable Convertible Preferred Stock and Series B Redeemable Convertible Preferred Stock on a 3.8044-for-1 basis without payment of additional consideration.

(2) These shares are held by Vida Ventures II, LLC ("VV II"). VV Manager II, LLC ("VVM II") is the manager of VV II and may be deemed to have voting, investment and dispositive power with respect to the shares held by VV II. Arie Belldegrun, Fred Cohen, and Leonard Potter, the members of the management committee of VVM II, along with the other members of the investment committee of VVM II, Rajul Jain, Joshua Kazam, and the Reporting Person, a member of the Issuer's board of directors, may be deemed to share voting, investment and dispositive power over the shares held by VV II and each such person disclaims beneficial ownership of the securities except to the extent of such person's pecuniary interest therein.

(3) These shares are held by Vida Ventures II-A, LLC ("VV II-A"). VVM II is the manager of VV II-A and may be deemed to have voting, investment and dispositive power with respect to the shares held by VV II-A. Arie Belldegrun, Fred Cohen, and Leonard Potter, the members of the management committee of VVM II, along with the other members of the investment committee of VVM II, Rajul Jain, Joshua Kazam, and the Reporting Person, a member of the Issuer's board of directors, may be deemed to share voting, investment and dispositive power over the shares held by VV II-A and each such person disclaims beneficial ownership of the securities except to the extent of such person's pecuniary interest therein.

(4) The Series A Redeemable Convertible Preferred Stock had no expiration date and automatically converted into the Issuer's Common Stock on a 3.8044-for-1 basis immediately prior to the closing of the Issuer's initial public offering of its Common Stock without payment of additional consideration.

(5) The Series B Redeemable Convertible Preferred Stock had no expiration date and automatically converted into the Issuer's Common Stock on a 3.8044-for-1 basis immediately prior to the closing of the Issuer's initial public offering of its Common Stock without payment of additional consideration.

**Signature:** /s/ Karen McCarthy, as 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.**