Century Therapeutics CEO has 463 shares withheld

Century Therapeutics’ CEO had a small number of shares withheld to cover taxes on RSU vesting, with overall share ownership essentially unchanged.

Rhea-AI Filing Summary

Century Therapeutics, Inc. (IPSC) reported that President and CEO Brent Pfeiffenberger had 463 shares of common stock withheld on September 4, 2026 to satisfy tax withholding obligations arising from the vesting of restricted stock units. This tax-withholding disposition was priced at $2.11 per share, and he now directly holds 3,633,839 common shares. No Rule 10b5-1 trading plan is reported for this transaction.

Insider Trade Summary

Tax Withholding: 463 shares

Tax Withholding 1 txn

Insider Pfeiffenberger Brent

Role President and CEO

Type	Security	Shares	Price	Value
Tax Withholding	Common Stock F1	463	$2.11	$976.93

Holdings After Transaction: Common Stock — 3,633,839 shares (Direct)

Footnotes (1)

1. F1. Represents shares withheld by the Issuer to satisfy tax withholding obligations in connection with the vesting of restricted stock units.

Key Figures

Shares withheld for tax: 463 shares Per-share valuation for withholding: $2.11 per share Shares held after transaction: 3,633,839 shares

3 metrics

Shares withheld for tax 463 shares Shares of common stock withheld on September 4, 2026 to satisfy tax withholding obligations on RSU vesting

Per-share valuation for withholding $2.11 per share Value used for the 463 shares withheld to cover tax obligations

Shares held after transaction 3,633,839 shares Century Therapeutics common stock directly held by the CEO after the September 4, 2026 transaction

Key Terms

restricted stock units, tax withholding obligations, withheld by the Issuer

3 terms

restricted stock units financial

"in connection with the vesting of restricted stock units"

Restricted stock units are a type of company reward where employees are promised shares of stock, but they only fully own these shares after meeting certain conditions, like staying with the company for a set time. They matter because they can become valuable assets and are often used to motivate employees to help the company succeed.

tax withholding obligations financial

"to satisfy tax withholding obligations in connection with the vesting"

withheld by the Issuer financial

"Represents shares withheld by the Issuer to satisfy tax withholding"

FAQ

What insider transaction did Century Therapeutics (IPSC) report for its CEO?

Century Therapeutics reported that President and CEO Brent Pfeiffenberger had 463 shares of common stock withheld on September 4, 2026 to satisfy tax withholding obligations tied to vesting restricted stock units.

Was the Century Therapeutics (IPSC) CEO transaction a market sale or a tax withholding?

The transaction was a tax-withholding disposition, not an open-market sale. The 463 shares were withheld by Century Therapeutics to cover tax withholding obligations from vesting restricted stock units.

At what price were the withheld Century Therapeutics (IPSC) shares valued?

The 463 withheld shares of Century Therapeutics common stock were valued at $2.11 per share in connection with satisfying tax withholding obligations on RSU vesting.

How many Century Therapeutics (IPSC) shares does the CEO hold after this transaction?

After the September 4, 2026 tax-withholding event, President and CEO Brent Pfeiffenberger directly holds 3,633,839 shares of Century Therapeutics common stock.

Was the Century Therapeutics (IPSC) CEO transaction under a Rule 10b5-1 trading plan?

No. The filing indicates that the Rule 10b5-1 checkbox is not affirmed, so this tax-withholding transaction was not reported as executed under a Rule 10b5-1 trading plan.

AI-generated analysis. How Rhea-AI works. Not financial advice.

Form 4 Insider Transactions: What Each Field Means →

See more from StockTitan in Google Search and AI answers. Adds StockTitan as a preferred source · opens Google

Add on Google Not now

Available on EDGAR 09/09/2026 - 04:37 PM Accepted by SEC EDGAR 09/09/2026 - 04:36 PM Learn about SEC filing dates

SEC Form 4

FORM 4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL

OMB Number:			3235-0287
Estimated average burden
hours per response:			0.5

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^*

Pfeiffenberger Brent

(Last) (First) (Middle)

C/O CENTURY THERAPEUTICS, INC.

25 N 38TH STREET, 12TH FLOOR

(Street)

PHILADELPHIA PENNSYLVANIA 19104

(City) (State) (Zip)

UNITED STATES

(Country)

2. Issuer Name and Ticker or Trading Symbol
Century Therapeutics, Inc. [ IPSC ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

X	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	President and CEO

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
09/04/2026

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

4. If Amendment, Date of Original Filed (Month/Day/Year)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Common Stock	09/04/2026		F(1)		463	D	$2.11	3,633,839	D

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares

Explanation of Responses:

1. Represents shares withheld by the Issuer to satisfy tax withholding obligations in connection with the vesting of restricted stock units.

	/s/ Douglas Carr, Attorney-in-Fact	09/09/2026
	** Signature of Reporting Person	Date
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.
* Form 4: SEC 1474 (03-26)