Murat Kalayoglu - 31 Mar 2026 SCHEDULE 13D/A Report for Cartesian Therapeutics, Inc. Common Stock (RNAC)

Filing manager: Murat Kalayoglu
Reporting owner: Murat Kalayoglu
Security: Cartesian Therapeutics, Inc. Common Stock
Beneficially owned shares: 5,833,971 shares
Large-stake signal: Form
SCHEDULE 13D/A
Active or control-oriented beneficial ownership filing.
Ownership
20%
Beneficial ownership of this reported class.
Shares
5,833,971 shares
Shares beneficially owned as disclosed.
Event date
31 Mar 2026
Date tied to the ownership event or amendment.
Accepted by SEC
02 Apr 2026
EDGAR 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: 20%
Symbol: RNAC
Shares outstanding: 29,316,437 shares
SEC form: SCHEDULE 13D/A
Accepted by SEC: 02 Apr 2026, 17:37:40 UTC
Event date: 31 Mar 2026
Source filing: View source filing

Key filing fact

Murat Kalayoglu disclosed 20% ownership in Cartesian Therapeutics, Inc. Common Stock (RNAC) on 31 Mar 2026.

Key facts

Murat Kalayoglu filed SCHEDULE 13D/A for Cartesian Therapeutics, Inc. Common Stock (RNAC).
Disclosed ownership: 20%.
Date of event: 31 Mar 2026.

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.

Backed by Schedule 13D/13G

Beneficial ownership values are sourced from the original SEC Schedule 13D/13G filing.

Reporting persons

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
Murat Kalayoglu	20%	5,833,971	5,833,971	0	/s/ Murat Kalayoglu	Murat Kalayoglu	0002000002
Seven One Eight Three Four Irrevocable Trust	18%	5,313,261	5,313,261	0	/s/ Murat Kalayoglu	Murat Kalayoglu, Authorized Person	0002000959
Elizabeth Hoge	18%	5,313,261	0	5,313,261	/s/ Murat Kalayoglu	Murat Kalayoglu, Authorized Person	0002000987
Sinan Kalayoglu	18%	5,313,261	0	5,313,261	/s/ Murat Kalayoglu	Murat Kalayoglu, Authorized Person

CIK / CUSIP context first

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