# EDGAR Filing Document

**Accession Number:** 0001776851
**File Stem:** 0001193125-26-008030
**Filing Date:** 2026-1
**Character Count:** 9162
**Document Hash:** 93fa823f05d639c7489853b401110fee
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001193125-26-008030.hdr.sgml**: 20260108

**ACCESSION NUMBER**: 0001193125-26-008030

**CONFORMED SUBMISSION TYPE**: 3

**PUBLIC DOCUMENT COUNT**: 1

**CONFORMED PERIOD OF REPORT**: 20260108

**FILED AS OF DATE**: 20260108

**DATE AS OF CHANGE**: 20260108

**REPORTING-OWNER**: 

**OWNER DATA:**
- **COMPANY CONFORMED NAME:** Vida Ventures II, LLC
- **CENTRAL INDEX KEY:** 0001776851

**ORGANIZATION NAME:**
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** 3
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-43047
- **FILM NUMBER:** 26521137

**BUSINESS ADDRESS:**
- **STREET 1:** 10100 SANTA MONICA BLVD
- **STREET 2:** FLOOR 15
- **CITY:** LOS ANGELES
- **STATE:** CA
- **ZIP:** 90067
- **BUSINESS PHONE:** 857-254-9492

**MAIL ADDRESS:**
- **STREET 1:** 10100 SANTA MONICA BLVD
- **STREET 2:** FLOOR 15
- **CITY:** LOS ANGELES
- **STATE:** CA
- **ZIP:** 90067
**REPORTING-OWNER**: 

**OWNER DATA:**
- **COMPANY CONFORMED NAME:** VIDA VENTURES II-A, LLC
- **CENTRAL INDEX KEY:** 0001781930

**ORGANIZATION NAME:**
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** 3
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-43047
- **FILM NUMBER:** 26521136

**BUSINESS ADDRESS:**
- **STREET 1:** 10100 SANTA MONICA BLVD
- **STREET 2:** FLOOR 15
- **CITY:** LOS ANGELES
- **STATE:** CA
- **ZIP:** 90067
- **BUSINESS PHONE:** 857-254-9492

**MAIL ADDRESS:**
- **STREET 1:** 10100 SANTA MONICA BLVD
- **STREET 2:** FLOOR 15
- **CITY:** LOS ANGELES
- **STATE:** CA
- **ZIP:** 90067
**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 3

### INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES

[ ] Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

---

| | | |
|:---|:---|:---|
| **1. Name and Address of Reporting Person**<sup>*</sup><br>Vida Ventures II, LLC<br><sub>(Last) (First) (Middle)</sub><br>C/O VIDA VENTURES ADVISORS, LLC<br>10100 SANTA MONICA BOULEVARD, SUITE 1500<br><sub>(Street)</sub><br>LOS ANGELES, CA 90067<br><sub>(City) (State) (Zip)</sub> | **3. Issuer Name and Ticker or Trading Symbol**<br>Aktis Oncology, Inc. [ AKTS ] | **5. If Amendment, Date of Original Filed (Month/Day/Year)**<br>  |
| **2. Date of Event Requiring Statement (Month/Day/Year)**<br>2026-01-08 | **4. Relationship of Reporting Person(s) to Issuer**<br>(Check all applicable)<br>[ ] Director   [X] 10% Owner<br>[ ] Officer (give title below)   [ ] Other (specify below)<br>_ _ | **6. Individual or Joint/Group Filing (Check Applicable Line)**<br>[ ] Form filed by One Reporting Person<br>[X] Form filed by More than One Reporting Person |

---

---

| | | |
|:---|:---|:---|
| **1. Name and Address of Reporting Person**<sup>*</sup><br>VIDA VENTURES II-A, LLC<br><sub>(Last) (First) (Middle)</sub><br>10100 SANTA MONICA BOULEVARD.,<br>SUITE 1500<br><sub>(Street)</sub><br>LOS ANGELES, CA 90067<br><sub>(City) (State) (Zip)</sub> | **3. Issuer Name and Ticker or Trading Symbol**<br>Aktis Oncology, Inc. [ AKTS ] | **5. If Amendment, Date of Original Filed (Month/Day/Year)**<br>  |
| **2. Date of Event Requiring Statement (Month/Day/Year)**<br>2026-01-08 | **4. Relationship of Reporting Person(s) to Issuer**<br>(Check all applicable)<br>[ ] Director   [X] 10% Owner<br>[ ] Officer (give title below)   [ ] Other (specify below)<br>_ _ | **6. Individual or Joint/Group Filing (Check Applicable Line)**<br>[ ] Form filed by One Reporting Person<br>[X] Form filed by More than One Reporting Person |

---

## Table I - Non-Derivative Securities Beneficially Owned

---

|  |  |  |  |
| --- | --- | --- | --- |
| 1. Title of Security | 2. Amount of Securities Beneficially Owned | 3. Ownership Form | 4. Nature of Indirect Beneficial Ownership |

---

## Table II - Derivative Securities Beneficially Owned

---

|  |  |  |  |  |  |  |  |
| --- | --- | --- | --- | --- | --- | --- | --- |
| 1. Title of Derivative Security | 2. Date Exercisable and Expiration Date (Month/Day/Year) | 2. Date Exercisable and Expiration Date (Month/Day/Year) | 3. Title and Amount of Underlying Securities | 3. Title and Amount of Underlying Securities | 4. Conversion or Exercise Price | 5. Ownership Form | 6. Nature of Indirect Beneficial Ownership |
| 1. Title of Derivative Security | Date Exercisable | Expiration Date | Title | Amount or Number of Shares | 4. Conversion or Exercise Price | 5. Ownership Form | 6. Nature of Indirect Beneficial Ownership |
| Series A Redeemable Convertible Preferred Stock | <sup>(1)</sup> | <sup>(1)</sup> | Common Stock | 3900284 | <sup>(1)</sup> | I | See Footnote<sup>(2)</sup> |
| Series A Redeemable Convertible Preferred Stock | <sup>(1)</sup> | <sup>(1)</sup> | Common Stock | 108229 | <sup>(1)</sup> | I | See Footnote<sup>(3)</sup> |
| Series B Redeemable Convertible Preferred Stock | <sup>(4)</sup> | <sup>(4)</sup> | Common Stock | 959086 | <sup>(4)</sup> | I | See Footnote<sup>(2)</sup> |
| Series B Redeemable Convertible Preferred Stock | <sup>(4)</sup> | <sup>(4)</sup> | Common Stock | 26613 | <sup>(4)</sup> | I | See Footnote<sup>(3)</sup> |

---

### Footnotes:

(1) Each share of Series A Redeemable Convertible Preferred Stock is convertible into shares of the Issuer's Common Stock on a 3.8044-for-1 basis and has no expiration date. All shares of Series A Redeemable Convertible Preferred Stock will automatically convert on a 3.8044-for-1 basis into shares of Common Stock immediately prior to the closing of the Issuer's initial public offering of its Common Stock 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 Helen Kim, 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 Helen Kim, 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) Each share of Series B Redeemable Convertible Preferred Stock is convertible into shares of the Issuer's Common Stock on a 3.8044-for-1 basis and has no expiration date. All shares of Series B Redeemable Convertible Preferred Stock will automatically convert on a 3.8044-for-1 basis into shares of Common Stock immediately prior to the closing of the Issuer's initial public offering of its Common Stock without payment of additional consideration.

**Signature:** VIDA VENTURES II, LLC, By: VV Manager II, LLC, its Manager, By: /s/ Jean-Philippe Kouakou-Zebouah, Authorized Signatory  
**Date:** 2026-01-08

**Signature:** VIDA VENTURES II-A, LLC, By: VV Manager II, LLC, its Manager, By: /s/ Jean-Philippe Kouakou-Zebouah, Authorized Signatory  
**Date:** 2026-01-08

### 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.**