What SEC filings does Cartesian Therapeutics, Inc. submit to the SEC?

Cartesian Therapeutics, Inc. (RNAC) submits several types of SEC filings including Form 4 (insider transactions), Form 144 (proposed insider sales), 8-K reports (material events such as earnings releases, acquisitions, leadership changes), and periodic reports — the 10-Q (quarterly) and 10-K (annual). All filings are publicly available through SEC EDGAR.

What does a Form 4 filing tell me about RNAC?

A Form 4 for RNAC discloses a transaction by a company insider — typically a director, officer, or 10%+ shareholder. It shows the source-reported date, number of shares, price, and updated ownership. These facts do not establish motive or predict future returns.

How do I interpret an 8-K filing from Cartesian Therapeutics, Inc.?

An 8-K signals a material event requiring prompt disclosure. Common triggers include earnings pre-announcements, acquisitions, leadership appointments or departures, credit changes, or regulatory actions. Read the item codes inside the filing to understand exactly what was disclosed before drawing conclusions.

What is the difference between a 10-K and 10-Q for RNAC?

The 10-K is Cartesian Therapeutics, Inc.'s annual report with fully audited financial statements, comprehensive MD&A, and complete risk factor disclosures — filed 60–90 days after fiscal year-end. The 10-Q is a lighter quarterly report with unaudited financials filed for the first three quarters. Together they provide a continuous financial picture of the company.

Where can I see all RNAC SEC filings directly on EDGAR?

You can view all historical Cartesian Therapeutics, Inc. filings on the SEC EDGAR company page for RNAC. Each filing card on this page links directly to the original SEC document.

How often does Cartesian Therapeutics, Inc. file with the SEC?

Cartesian Therapeutics, Inc. files one 10-K per year and up to three 10-Qs per year. Form 4 insider transactions must be reported within two business days of each trade, so the frequency depends on how often insiders are buying or selling RNAC shares. 8-K filings occur whenever a material event happens — which can be several times per quarter for an active company.

RNAC SEC Filing News — Cartesian Therapeutics, Inc.

Latest SEC filings for Cartesian Therapeutics, Inc. (RNAC) explained in plain English. Covers insider buying and selling (Form 4), proposed insider sales (Form 144), material company events (8-K), and quarterly & annual reports (10-Q / 10-K). StrongBuyAnalytics provides navigation and brief excerpts or summaries; original filings remain at the SEC/source links and were authored by their filers, not StrongBuyAnalytics. Filing dates shown are source dates. Coverage and detection can be delayed or incomplete because of SEC availability, amendments, parsing, caching, or outages. Latest source filing date shown: 2026-09-29.

Cartesian Therapeutics, Inc., a clinical-stage biotechnology company, provides mRNA cell therapies for the treatment of autoimmune diseases. The company's lead product candidate is Descartes-08, an autologous mRNA chimeric antigen receptor T-cell therapy (CAR-T) directed against the B cell maturation antigen (BCMA), which is in Phase 2b clinical trials for the treatment of autoimmune diseases, generalized myasthenia gravis, and systemic lupus erythematosus, as well as rare pediatric disease desi…

Sector: Healthcare Industry: Biotechnology Market Cap: $189.7M CIK: 1453687

Total Filings

Bullish Classifications

Bearish Classifications

Insider Transactions

Material Events (8-K)

Periodic Reports

Rule-based classifications for RNAC currently lean bearish. Of the 20 filing records displayed, 1 carry bearish classifications (such as insider sales or negative 8-K disclosures) versus 0 bullish. This does not necessarily signal fundamental deterioration — insiders sell for many reasons — but it is worth monitoring alongside the company's core financial metrics.

RNAC Filing Activity Snapshot 2026-01-08 — 2026-09-29

Insider Transactions (Form 4)

0 buys vs 1 sell

Net insider selling in this period — insiders sell for many reasons beyond conviction.

Largest Form 144 Filing

$232.7K

MILOS MILJKOVIC · 2026-06-09

35,038 shares · Form 144

Form 144 Notices

Proposed insider sales filed — Form 144 is a notice of intent, not a confirmed transaction. Actual sales are confirmed via Form 4.

Insider Transactions 4 · Forms 3, 4 and 5

A Form 4 is filed within two business days of a company insider — an officer, a director, or a holder of more than ten percent of the stock — changing their position in the shares. All 4 filings in this group are Form 4s for Cartesian Therapeutics, Inc.

The difficulty with reading these filings as a group is that a single form type covers transactions that mean entirely different things. An executive spending their own money to buy stock and an executive having shares withheld to pay tax on a vesting grant both appear as a Form 4. Every filing below is therefore tagged with the nature of the underlying transaction, taken from the transaction code reported on the form itself.

Across the 4 insider filings shown, the breakdown is 2 option exercise, 1 gift and 1 open-market sale. 1 of them involved a discretionary open-market trade; the rest are compensation and administrative mechanics.

What each transaction type means

Option exercise ×2: The insider converted options into shares. The exercise price was fixed when the options were granted, so the timing usually tracks an expiry schedule.
Gift ×1: Shares were transferred as a gift, typically for estate or charitable planning. No sale into the market took place.
Open-market sale ×1: The insider sold shares on the open market. Sales may be discretionary or executed automatically under a pre-arranged Rule 10b5-1 trading plan, and a Form 4 does not always make clear which applies.

Form 4 Option exercise Tax / Compensation Filing 2026-04-06

RNAC insider Form 4 filed for equity award, exercise, or tax withholding

Hoge Elizabeth (10% Owner) filed a Form 4 covering compensation-related activity such as stock awards, option exercises, conversions, or tax withholding. These filings are usually neutral.

The insider converted options into shares. The exercise price was fixed when the options were granted, so the timing usually tracks an expiry schedule.

Transactions reported on this filing
Code	Nature	Shares	Price	Value
`M`	Option exercise	758,001	—	—
`M`	Option exercise derivative · Series A Non-Voting Convertible Preferred Stock	22,740	—	—

Filing: Form 4 (Insider Transaction) Insider: Hoge Elizabeth (10% Owner) Shares: 758,001

View on SEC EDGAR → Open Filing Document →

Form 4 Option exercise Tax / Compensation Filing 2026-04-06

RNAC insider Form 4 filed for equity award, exercise, or tax withholding

Kalayoglu Murat (10% Owner) filed a Form 4 covering compensation-related activity such as stock awards, option exercises, conversions, or tax withholding. These filings are usually neutral.

The insider converted options into shares. The exercise price was fixed when the options were granted, so the timing usually tracks an expiry schedule.

Transactions reported on this filing
Code	Nature	Shares	Price	Value
`M`	Option exercise	758,001	—	—
`M`	Option exercise derivative · Series A Non-Voting Convertible Preferred Stock	22,740	—	—

Filing: Form 4 (Insider Transaction) Insider: Kalayoglu Murat (10% Owner) Shares: 758,001

View on SEC EDGAR → Open Filing Document →

Form 4 Gift Tax / Compensation Filing 2026-03-13

RNAC insider Form 4 filed for equity award, exercise, or tax withholding

Singer Michael (Director) filed a Form 4 covering compensation-related activity such as stock awards, option exercises, conversions, or tax withholding. These filings are usually neutral.

Shares were transferred as a gift, typically for estate or charitable planning. No sale into the market took place.

Transactions reported on this filing
Code	Nature	Shares	Price	Value
`G`	Gift	6,555	—	—

Filing: Form 4 (Insider Transaction) Insider: Singer Michael (Director) Shares: 6,555

View on SEC EDGAR → Open Filing Document →

Form 4 Open-market sale Insider Selling 2026-01-08

RNAC insider Brunn Carsten (Director, President and CEO) sold 23,766 shares (~$162.1K)

Brunn Carsten, listed as Director, President and CEO at Cartesian Therapeutics, Inc., reported an open-market sale of 23,766 RNAC shares in a Form 4 filing. This is a confirmed insider sale, not just a proposed sale notice.

The insider sold shares on the open market. Sales may be discretionary or executed automatically under a pre-arranged Rule 10b5-1 trading plan, and a Form 4 does not always make clear which applies.

Transactions reported on this filing
Code	Nature	Shares	Price	Value
`S`	Open-market sale	23,766	$6.82	$162.1K

Filing: Form 4 (Insider Transaction) Insider: Brunn Carsten (Director, President and CEO) Shares: 23,766 Est. Value: $162.1K

View on SEC EDGAR → Open Filing Document →

Proposed Insider Sales 4 · Form 144

A Form 144 is a notice of intent to sell restricted or control securities. It is not a record that anything was sold. Cartesian Therapeutics, Inc. has 4 such notices in this period.

The distinction matters because a Form 144 is frequently reported as though it were a completed insider sale. The filer may sell all of the shares covered, some of them, or none at all, and there is no obligation to update the notice either way. A sale that is actually executed by an officer or director shows up separately on a Form 4, which is the filing to check before treating a proposed sale as a real one.

Form 144 Proposed Insider Sale 2026-06-09

RNAC Form 144 filed for proposed insider sale by MILOS MILJKOVIC (35,038 shares) ~$232.7K

MILOS MILJKOVIC filed a Form 144 with the SEC indicating intent to sell RNAC (Cartesian Therapeutics, Inc.) shares. Form 144 reflects a proposed sale, not a completed transaction. The actual execution, if any, would typically appear later in a Form 4.

Filing: Form 144 (Proposed Sale Notice) Insider: MILOS MILJKOVIC Shares: 35,038 Est. Value: $232.7K

View on SEC EDGAR → Open Filing Document →

Form 144 Proposed Insider Sale 2026-06-02

RNAC Form 144 filed for proposed insider sale by MILOS MILJKOVIC (3,924 shares) ~$25.2K

Filing: Form 144 (Proposed Sale Notice) Insider: MILOS MILJKOVIC Shares: 3,924 Est. Value: $25.2K

View on SEC EDGAR → Open Filing Document →

Form 144 Proposed Insider Sale 2026-01-13

RNAC Form 144 filed for proposed insider sale by CHRISTOPHER M JEWELL (9,000 shares) ~$68.9K

CHRISTOPHER M JEWELL filed a Form 144 with the SEC indicating intent to sell RNAC (Cartesian Therapeutics, Inc.) shares. Form 144 reflects a proposed sale, not a completed transaction. The actual execution, if any, would typically appear later in a Form 4.

Filing: Form 144 (Proposed Sale Notice) Insider: CHRISTOPHER M JEWELL Shares: 9,000 Est. Value: $68.9K

View on SEC EDGAR → Open Filing Document →

Form 144 Proposed Insider Sale 2026-01-09

RNAC Form 144 filed for proposed insider sale by CHRISTOPHER M JEWELL (1,510 shares) ~$12.1K

Filing: Form 144 (Proposed Sale Notice) Insider: CHRISTOPHER M JEWELL Shares: 1,510 Est. Value: $12.1K

View on SEC EDGAR → Open Filing Document →

Material Events 9 · Form 8-K

An 8-K reports a material event in the window between scheduled reports. There are 9 in this period for Cartesian Therapeutics, Inc. Each 8-K names the item number it is filed under, and that number is the fastest way to tell a routine disclosure from a consequential one.

Item 2.02 is an earnings release, Item 5.02 is a change of directors or officers, and Item 1.01 or 2.01 covers a material agreement or a completed acquisition. Item 7.01 and Item 8.01 are the general-purpose disclosure items and carry no fixed meaning on their own.

Form 8-K Material Company Update 2026-09-29