Form
SCHEDULE 13D
Active or control-oriented beneficial ownership filing.
MPM BIOVENTURES 2018, L.P. - 12 Jan 2026 SCHEDULE 13D Report for AKTIS ONCOLOGY, INC. Common Stock (AKTSQ)
- Filing manager
- MPM BIOVENTURES 2018, L.P.
- Reporting owner
- ANSBERT GADICKE
- Security
- AKTIS ONCOLOGY, INC. Common Stock
- Beneficially owned shares
- 10,260,064 shares
- Large-stake signal
-
Ownership
19%Beneficial ownership of this reported class.
Shares
10,260,064 sharesShares beneficially owned as disclosed.
Event date
12 Jan 2026Date tied to the ownership event or amendment.
Accepted by SEC
20 Jan 2026EDGAR acceptance date.
How to read this large-stake filing
- Schedule 13D/G filings focus on beneficial ownership stakes, not a full portfolio.
- Compare this filing with the holder history and issuer page before treating the percentage as a current position.
- Use amendments to understand whether the disclosed stake increased, decreased, or changed reporting status.
- Class ownership
- 19%
- Symbol
- AKTSQ
- Shares outstanding
- 53,160,953 shares
- SEC form
- SCHEDULE 13D
- Accepted by SEC
- 20 Jan 2026, 17:44:53 UTC
- Event date
- 12 Jan 2026
- Source filing
- View source filing
Ownership signal
CIK-linked ownership evidence from parsed SEC filings.
2 signals
Subject security
Names, identifiers, and filing context for this profile.
2 source fields
Source evidence
Original filing metadata and source links for verification.
4 source fields
Key filing fact
MPM BIOVENTURES 2018, L.P. disclosed 19% ownership in AKTIS ONCOLOGY, INC. Common Stock (AKTSQ) on 12 Jan 2026.
Key facts
- MPM BIOVENTURES 2018, L.P. filed SCHEDULE 13D for AKTIS ONCOLOGY, INC. Common Stock (AKTSQ).
- Disclosed ownership: 19%.
- Date of event: 12 Jan 2026.
Change
- No earlier schedule filing is available for direct comparison.
- Current filing was accepted on 20 Jan 2026, 17:44.
Research use
- This page turns one Schedule 13D/G filing into a quick large-stake read before the raw reporting-person rows.
- Use the linked SEC filing as the source of truth for ownership percentages, shares, and reporting-party details.
Evidence
Backed by Schedule 13D/13G
View source filing
Beneficial ownership values are sourced from the original SEC Schedule 13D/13G filing.
Reporting persons
Disclosed reporting parties (13)
Names, ownership percentages, voting power, signatures, titles, and CIKs as disclosed in this Schedule 13D/G filing.
| Name | Ownership | Shares owned | Sole voting power | Shared voting power | Signature | Title | CIK |
|---|---|---|---|---|---|---|---|
| MPM BIOVENTURES 2018, L.P. | 7.4% | 3,950,528 | 3,950,528 | 0 | /s/ Ansbert Gadicke | Managing director of MPM BioVentures 2018 LLC, the managing member of MPM BioVentures 2018 GP LLC, the GP of MPM BioVentures 2018, L.P. | 0001729505 |
| MPM BIOVENTURES 2018 (B), L.P. | 0.4% | 206,964 | 206,964 | 0 | /s/ Ansbert Gadicke | Managing director of MPM BioVentures 2018 LLC, the managing member of MPM BioVentures 2018 GP LLC, the GP of MPM BioVentures 2018(B), L.P. | 0001729504 |
| MPM BioVentures 2018 GP LLC | 7.8% | 4,157,492 | 0 | 4,157,492 | /s/ Ansbert Gadicke | Managing director of MPM BioVentures 2018 LLC, the managing member of MPM BioVentures 2018 GP LLC | 0001818701 |
| MPM ASSET MANAGEMENT INVESTORS BV2018 LLC | 0.1% | 77,911 | 77,911 | 0 | /s/ Ansbert Gadicke | Managing director of MPM BioVentures 2018 LLC, the manager of MPM Asset Management Investors BV2018 LLC | 0001734817 |
| MPM BioVentures 2018 LLC | 7.9% | 4,235,403 | 0 | 4,235,403 | /s/ Ansbert Gadicke | Managing Director | 0001818702 |
| MPM ONCOLOGY INNOVATIONS FUND LP | 1.6% | 847,080 | 847,080 | 0 | /s/ Ansbert Gadicke | Manager of MPM Oncology Innovations Fund GP LLC, the general partner of MPM Oncology Innovations Fund, L.P. | 0001719960 |
| MPM Oncology Innovations Fund GP LLC | 1.6% | 847,080 | 0 | 847,080 | /s/ Ansbert Gadicke | Manager | 0001857903 |
| Oncology Impact Private Investment Fund 2, L.P. | 9.1% | 4,835,872 | 4,835,872 | 0 | /s/ Ansbert Gadicke | Managing member of MPM Oncology Investments 2 LLC, the general partner of Oncology Impact Private Investment Fund 2, L.P. | 0002104306 |
| MPM Oncology Investments 2 LLC | 9.1% | 4,835,872 | 0 | 4,835,872 | /s/ Ansbert Gadicke | Managing Member | |
| MPM ASSET MANAGEMENT LLC | 0.6% | 341,709 | 341,709 | 0 | /s/ Ansbert Gadicke | Manager | 0001263048 |
| ANSBERT GADICKE | 19% | 10,260,064 | 0 | 10,260,064 | /s/ Ansbert Gadicke | Ansbert Gadicke | 0001134655 |
| LUKE EVNIN | 9.5% | 5,082,483 | 0 | 5,082,483 | /s/ Luke Evnin | Luke Evnin | 0001134657 |
| Todd Foley | 8% | 4,237,506 | 2,103 | 4,235,403 | /s/ Todd Foley | Todd Foley | 0001473930 |
CIK / CUSIP context first