Century Therapeutics CEO has 13,850 shares withheld

Century Therapeutics’ CEO had shares withheld to cover taxes on RSU vesting, with more than 3.6 million shares remaining held directly.

Available on EDGAR 09/15/2026 - 06:24 PM EDT Accepted by SEC EDGAR 09/15/2026 - 06:23 PM EDT Learn about SEC filing dates

Rhea-AI Filing Summary

Century Therapeutics, Inc. (IPSC) reported that President and CEO Brent Pfeiffenberger had 13,850 shares of common stock withheld on September 11, 2026 to satisfy tax withholding obligations related to the vesting of restricted stock units. After this tax-withholding disposition, he beneficially holds 3,633,839 common shares directly. No Rule 10b5-1 trading plan is reported.

Insider Trade Summary

Tax Withholding: 13,850 shares

Tax Withholding 1 txn

Insider Pfeiffenberger Brent

Role President and CEO

Type	Security	Shares	Price	Value
Tax Withholding	Common Stock F1	13,850	$1.94	$27K

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

Holdings Before and After: Common Stock, 3,647,689 to 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 taxes: 13,850 shares Price per share for tax withholding: $1.94 per share Shares held after transaction: 3,633,839 shares +1 more

4 metrics

Shares withheld for taxes 13,850 shares Common stock withheld on September 11, 2026 for tax withholding obligations

Price per share for tax withholding $1.94 per share Value applied to shares withheld in the September 11, 2026 transaction

Shares held after transaction 3,633,839 shares Century Therapeutics common stock held directly by Brent Pfeiffenberger after the transaction

Tax-withholding transactions reported 1 transaction Number of Form 4 code F transactions on September 11, 2026

Key Terms

restricted stock units, tax withholding obligations, beneficially holds

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

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

beneficially holds financial

"After this tax-withholding disposition, he beneficially holds 3,633,839"

FAQ

AI-generated questions and answers. How Rhea-AI works. Not financial advice.

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

Century Therapeutics reported that President and CEO Brent Pfeiffenberger had 13,850 shares of common stock withheld on September 11, 2026 to satisfy tax withholding obligations arising from the vesting of restricted stock units.

How many IPSC shares does the CEO hold after this Form 4 transaction?

After the reported tax-withholding disposition, Brent Pfeiffenberger beneficially holds 3,633,839 shares of Century Therapeutics common stock directly, according to the Form 4 filing.

Was the September 11, 2026 IPSC insider transaction a market sale?

No. The Form 4 states the transaction was a payment of tax liability by delivering or withholding securities in connection with RSU vesting, not an open-market sale.

What was the price used for the IPSC shares withheld for the CEO’s taxes?

The filing reports a price of $1.94 per share for the 13,850 Century Therapeutics shares withheld to satisfy tax withholding obligations on September 11, 2026.

Was a Rule 10b5-1 trading plan involved in this IPSC Form 4 transaction?

No. The document-level Rule 10b5-1 checkbox is marked false, indicating that the September 11, 2026 tax-withholding transaction was not reported as being made under a Rule 10b5-1 trading plan.

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

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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)
09/11/2026

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	09/11/2026		F(1)		13,850	D	$1.94	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	09/15/2026
	** 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)