[Form 3] TScan Therapeutics, Inc. Initial Statement of Beneficial Ownership

Rhea-AI Filing Summary

Dworak Leiden, reporting as an officer (Principal Accounting Officer) of TScan Therapeutics, Inc. (TCRX), filed an initial Form 3 reporting ownership of stock options granted by the company. The Form 3 reflects six option grants exercisable between 04/03/2032 and 01/02/2035 covering a total of 366,925 shares of Voting Common Stock with exercise prices ranging from $1.81 to $6.00. Vesting schedules are described for each grant, generally providing 25% vesting after one year followed by equal monthly vesting over 36 months, with certain tranches tied to service dates or shareholder approval. The filing date for the event is 08/14/2025 and the Form is signed by an attorney-in-fact on behalf of the reporting person.

Positive

• 366,925 stock options reported, showing clear disclosure of equity compensation
• Each option grant includes explicit vesting schedules (25% at one year, then monthly over 36 months) providing transparency

Negative

• None.

Insights

Financial Analyst

TL;DR: Officer holds options for 366,925 shares with multi-year vesting; disclosure is routine initial ownership reporting.

The Form 3 documents option-based compensation rather than open-market purchases or sales, showing seven-year plus exercise horizons and standard time-based vesting schedules. The total optioned shares (366,925) and stated exercise prices provide transparency on potential future dilution if exercised, but the filing does not disclose current exercised shares, cash proceeds, or percentage ownership versus outstanding shares, limiting assessment of immediate financial impact.

Corporate Governance Expert

TL;DR: This is a routine initial Section 16 filing by an officer detailing stock option grants and vesting terms.

The filing correctly identifies the reporting person as an officer and provides explicit vesting schedules and grant approvals where applicable. It includes a power of attorney signature. There are no indications of related-party transactions, accelerated vesting triggers, or departures from standard equity award practices in the disclosed text.

SEC Form 3

FORM 3

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

INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES

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

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1. Name and Address of Reporting Person^*

Dworak Leiden

(Last) (First) (Middle)

C/O TSCAN THERAPEUTICS, INC.

830 WINTER STREET

(Street)

WALTHAM MA 02451

(City) (State) (Zip)

2. Date of Event Requiring Statement (Month/Day/Year)
08/14/2025

3. Issuer Name and Ticker or Trading Symbol
TScan Therapeutics, Inc. [ TCRX ]

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

	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	Principal Accounting Officer

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

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

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

Table I - Non-Derivative Securities Beneficially Owned
1. Title of Security (Instr. 4)	2. Amount of Securities Beneficially Owned (Instr. 4)	3. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	4. Nature of Indirect Beneficial Ownership (Instr. 5)

Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 4)	2. Date Exercisable and Expiration Date (Month/Day/Year)		3. Title and Amount of Securities Underlying Derivative Security (Instr. 4)		4. Conversion or Exercise Price of Derivative Security	5. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	6. Nature of Indirect Beneficial Ownership (Instr. 5)
	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
Stock Option (Right to Buy)	(1)	04/03/2032	Voting Common Stock	37,500	$2.9	D
Stock Option (Right to Buy)	(2)	02/01/2033	Voting Common Stock	23,750	$1.81	D
Stock Option (Right to Buy)	(3)	06/12/2033	Voting Common Stock	163,800	$2.49	D
Stock Option (Right to Buy)	(4)	07/20/2033	Voting Common Stock	25,000	$2.23	D
Stock Option (Right to Buy)	(5)	01/11/2034	Voting Common Stock	46,875	$6	D
Stock Option (Right to Buy)	(6)	01/02/2035	Voting Common Stock	70,000	$3.065	D

Explanation of Responses:

1. The shares subject to this option shall vest and become exercisable with respect to 25% of the shares on the one-year anniversary of April 4, 2022, with the balance vesting thereafter in equal monthly installments over the next 36 months of continuous service to the Issuer.

2. The shares subject to this option shall vest and become exercisable with respect to 25% of the shares on the one-year anniversary of February 2, 2023, with the balance vesting thereafter in equal monthly installments over the next 36 months of continuous service to the Issuer.

3. 96,300 shares subject to this option shall vest and become exercisable with respect to 25% of the shares on the one-year anniversary of May 24, 2023, with the balance vesting thereafter in equal monthly installments over the next 36 months of continuous service to the Issuer. The remaining 67,500 shares subject to this option shall vest and become exercisable with respect to 25% of the shares on February 2, 2025, with the balance vesting thereafter in equal monthly installments over the next 36 months of continuous service to the Issuer, in each case subject to the Reporting Person's continued service at such time. This option was granted on May 24, 2023 subject to the approval of the Issuers' stockholders of an amendment to the TScan Therapeutics, Inc. 2021 Equity Incentive Plan, which was obtained on June 13, 2023.

4. The shares subject to this option shall vest and become exercisable with respect to 25% of the shares on the one-year anniversary of July 21, 2023, with the balance vesting thereafter in equal monthly installments over the next 36 months of continuous service to the Issuer.

5. The shares subject to this option shall vest and become exercisable with respect to 25% of the shares on the one-year anniversary of January 12, 2024, with the balance vesting thereafter in equal monthly installments over the next 36 months of continuous service to the Issuer.

6. The shares subject to this option shall vest and become exercisable with respect to 25% of the shares on the one-year anniversary of January 3, 2025, with the balance vesting thereafter in equal monthly installments over the next 36 months of continuous service to the Issuer.

Remarks:

Exhibit List - Exhibit 24 - Power of Attorney

	/s/ Zoran Zdraveski, Attorney-in-Fact	08/22/2025
	** 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 5 (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.

FAQ

Who filed the Form 3 for TCRX?

The Form 3 was filed on behalf of Dworak Leiden, identified as an officer (Principal Accounting Officer) of TScan Therapeutics, Inc.

What securities are reported on the Form 3 for TCRX?

Six stock option grants are reported, collectively covering 366,925 shares of Voting Common Stock with exercise prices between $1.81 and $6.00.

When is the date of the event requiring this Form 3 filing?

The date of the event requiring the statement is 08/14/2025.

What are the vesting terms for the options reported on the Form 3?

Vesting generally provides 25% of shares on the one-year anniversary followed by equal monthly vesting over the next 36 months, with some tranches tied to specific service start dates or shareholder approvals.

Who signed the Form 3?

The Form is signed by /s/ Zoran Zdraveski, Attorney-in-Fact on 08/22/2025.