STOCK TITAN
  1. Home
  2. Sec-filings
  3. TCRX
  4. [Form 4] TScan Therapeutics, Inc. Insider Trading Activity

Baker-linked TScan (TCRX) director granted 67,000 stock options

Filing Impact
(Neutral)
Filing Sentiment
(Neutral)
Form Type
4

Rhea-AI Filing Summary

BAKER BROS. ADVISORS LP reported acquisition or exercise transactions in this Form 4 filing.

TScan Therapeutics, Inc. reported an insider Form 4 showing an award of 67,000 non-qualified stock options linked to its common stock. The options were granted to Dr. Stephen R. Biggar, who serves on the board, with a strike price of $0.9946 per share and expiration on May 19, 2036.

The options vest on the earlier of the first anniversary of the May 20, 2026 grant date or the next annual stockholder meeting, subject to Dr. Biggar’s continued board service. Under Baker Bros. Advisors LP policies, Dr. Biggar does not retain economic rights in these securities; related Baker funds instead hold an indirect proportionate pecuniary interest, and Baker-affiliated entities disclaim beneficial ownership beyond that interest.

Positive

  • None.

Negative

  • None.
Insider BAKER BROS. ADVISORS LP, 667, L.P., Baker Bros. Advisors (GP) LLC, Baker Brothers Life Sciences LP, BAKER FELIX, BAKER JULIAN
Role null | null | null | null | null | null
Type Security Shares Price Value
Grant/Award Non- Qualified Stock Option (right to buy) 67,000 $0.00 --
Grant/Award Non- Qualified Stock Option (right to buy) 67,000 $0.00 --
Holdings After Transaction: Non- Qualified Stock Option (right to buy) — 67,000 shares (Indirect, See Footnotes)
Footnotes (1)
  1. Includes 67,000 non-qualified stock options ("Stock Options") exercisable solely into common stock ("Common Stock") of TScan Therapeutics, Inc. (the "Issuer") granted by the Issuer to Dr. Stephen R. Biggar, a full-time employee of Baker Bros. Advisors LP (the "Adviser"), on May 20, 2026, in his capacity as a director of the Issuer, pursuant to the Issuer's Amended and Restated 2021 Equity Incentive Plan (the "Incentive Plan"). The Stock Options have a strike price of $0.9946 per share, and vest on the earlier of the first anniversary of the grant date or the date of the next annual meeting of stockholders of the Issuer, subject to Dr. Biggar's continued service on the board of directors of the Issuer (the "Board") through the vesting date. The Stock Options expire on May 19, 2036. Dr. Biggar serves on the Board as a representative of 667, L.P. ("667") and Baker Brothers Life Sciences, L.P. ("Life Sciences", and together with 667, the "Funds") and their affiliates and control persons. After giving effect to the transaction reported herein and as a result of their ownership interest in (i) Baker Biotech Capital, L.P. and (ii) 667, Julian C. Baker and Felix J. Baker each may be deemed to have an indirect pecuniary interest in the Stock Options reported in column 9 of Table II held for the benefit of 667, a limited partnership of which the sole general partner is Baker Biotech Capital, L.P., a limited partnership of which the sole general partner is Baker Biotech Capital (GP), LLC, due to their interest in 667 and Baker Biotech Capital, L.P.'s right to receive an allocation of a portion of the profits from 667. The Adviser serves as the investment adviser to the Funds. In connection with the services provided by the Adviser, the Adviser receives an asset-based management fee that does not confer any pecuniary interest in the securities held for the benefit of the Funds. Baker Bros. Advisors (GP) LLC ("the Adviser GP") is the Adviser's sole general partner. Julian C. Baker and Felix J. Baker are managing members of the Adviser GP. The Adviser has complete and unlimited discretion and authority with respect to the investment and voting power of the securities held for the benefit of the Funds. The general partners of the Funds relinquished to the Adviser all discretion and authority with respect to the investment and voting power of the securities held for the benefit of the Funds. Julian C. Baker, Felix J. Baker, the Adviser GP and the Adviser disclaim beneficial ownership of the securities held for the benefit of the Funds except to the extent of their pecuniary interest therein, and this report shall not be deemed an admission that any of Julian C. Baker, Felix J. Baker, the Adviser GP or the Adviser is a beneficial owner of such securities for purposes of Section 16 or any other purpose. Pursuant to the policies of the Adviser, Dr. Biggar does not have a right to any of the Issuer's securities issued as compensation for his service on the Board and the Funds are entitled to an indirect proportionate pecuniary interest in such securities. The Funds each own an indirect proportionate pecuniary interest in such securities. Solely as a result of their ownership interest in (i) the general partners of the Funds and (ii) the Funds, Felix J. Baker and Julian C. Baker may be deemed to have an indirect pecuniary interest in the shares of Common Stock, Stock Options and Common Stock issued upon exercise of Stock Options (i.e. no direct pecuniary interest) issued as compensation for such Board service. Pursuant to the policies of the Adviser, the Adviser has voting and dispositive power over the Stock Options and any Common Stock received as a result of the exercise of Stock Options. The acquisition of Stock Options reported on this form represents a single grant to Dr. Biggar of 67,000 Stock Options on Table II. This grant of 67,000 Stock Options for Dr. Biggar is reported for each of the Funds as each has an indirect pecuniary interest in such securities. After giving effect to the transaction reported herein and as a result of their ownership interest in (i) Baker Brothers Life Sciences Capital, L.P. and (ii) Life Sciences, Julian C. Baker and Felix J. Baker each may be deemed to have an indirect pecuniary interest in the Stock Options reported in column 9 of Table II held for the benefit of Life Sciences, a limited partnership of which the sole general partner is Baker Brothers Life Sciences Capital, L.P., a limited partnership of which the sole general partner is Baker Brothers Life Sciences Capital (GP), LLC, due to their interest in Life Sciences and Baker Brothers Life Sciences Capital, L.P.'s right to receive an allocation of a portion of the profits from Life Sciences.
Option grant size 67,000 options Non-qualified stock options granted May 20, 2026
Strike price $0.9946 per share Exercise price for TScan common stock under the options
Expiration date May 19, 2036 Stock options term end
Underlying shares 67,000 shares Common stock issuable upon option exercise
Vesting condition Earlier of 1-year or next annual meeting Subject to continued board service by Dr. Biggar
Non- Qualified Stock Option financial
"Includes 67,000 non-qualified stock options ("Stock Options") exercisable solely into common stock"
pecuniary interest financial
"may be deemed to have an indirect pecuniary interest in the Stock Options"
voting and dispositive power financial
"the Adviser has voting and dispositive power over the Stock Options"
Equity Incentive Plan financial
"pursuant to the Issuer's Amended and Restated 2021 Equity Incentive Plan (the "Incentive Plan")"
An equity incentive plan is a program that gives employees, executives or directors the right to receive company stock or options to buy stock as part of their pay. Think of it as offering slices of future company profit to motivate people to boost long‑term performance; for investors it matters because it can align employee goals with shareholder value but also increases the number of shares outstanding, which can dilute existing ownership.
beneficial ownership financial
"disclaim beneficial ownership of the securities held for the benefit of the Funds"
Beneficial ownership means the person or entity that actually enjoys the benefits of owning shares or other assets — such as receiving dividends, voting rights, or price gains — even if the legal title is held in another name. For investors it matters because knowing who truly controls and profits from a company reveals who can influence decisions, exposes potential conflicts of interest or hidden concentration of power, and affects transparency and risk in the stock.
Form 4 Insider Transactions: What Each Field Means →
SEC Form 4
FORM 4UNITED 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*
BAKER BROS. ADVISORS LP
(Last)(First)(Middle)
860 WASHINGTON STREET, 3RD FLOOR
(Street)
NEW YORK NEW YORK 10014
(City)(State)(Zip)
UNITED STATES
(Country)		2. Issuer Name and Ticker or Trading Symbol
TScan Therapeutics, Inc. [ TCRX ] 		5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
XDirector10% Owner
Officer (give title below)Other (specify below)
2a. Foreign Trading Symbol
3. Date of Earliest Transaction (Month/Day/Year)
05/20/2026		6. Individual or Joint/Group Filing (Check Applicable Line)
Form filed by One Reporting Person
XForm 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)
CodeVAmount(A) or (D)Price
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)
CodeV(A)(D)Date ExercisableExpiration DateTitleAmount or Number of Shares
Non- Qualified Stock Option (right to buy)$0.994605/20/2026A67,000(1) (1)05/19/2036Common Stock67,000$067,000ISee Footnotes(2)(3)(4)(5)(6)(7)(8)
Non- Qualified Stock Option (right to buy)$0.994605/20/2026A67,000(1) (1)05/19/2036Common Stock67,000$067,000ISee Footnotes(2)(4)(5)(6)(7)(8)(9)
1. Name and Address of Reporting Person*
BAKER BROS. ADVISORS LP
(Last)(First)(Middle)
860 WASHINGTON STREET, 3RD FLOOR
(Street)
NEW YORK NEW YORK 10014
(City)(State)(Zip)
UNITED STATES
(Country)
Relationship of Reporting Person(s) to Issuer
XDirector10% Owner
Officer (give title below)Other (specify below)
1. Name and Address of Reporting Person*
667, L.P.
(Last)(First)(Middle)
860 WASHINGTON STREET, 3RD FLOOR
(Street)
NEW YORK NEW YORK 10014
(City)(State)(Zip)
UNITED STATES
(Country)
Relationship of Reporting Person(s) to Issuer
XDirector10% Owner
Officer (give title below)Other (specify below)
1. Name and Address of Reporting Person*
Baker Bros. Advisors (GP) LLC
(Last)(First)(Middle)
860 WASHINGTON STREET, 3RD FLOOR
(Street)
NEW YORK NEW YORK 10014
(City)(State)(Zip)
UNITED STATES
(Country)
Relationship of Reporting Person(s) to Issuer
XDirector10% Owner
Officer (give title below)Other (specify below)
1. Name and Address of Reporting Person*
Baker Brothers Life Sciences LP
(Last)(First)(Middle)
860 WASHINGTON STREET, 3RD FLOOR
(Street)
NEW YORK NEW YORK 10014
(City)(State)(Zip)
UNITED STATES
(Country)
Relationship of Reporting Person(s) to Issuer
XDirector10% Owner
Officer (give title below)Other (specify below)
1. Name and Address of Reporting Person*
BAKER FELIX
(Last)(First)(Middle)
860 WASHINGTON STREET, 3RD FLOOR
(Street)
NEW YORK NEW YORK 10014
(City)(State)(Zip)
UNITED STATES
(Country)
Relationship of Reporting Person(s) to Issuer
XDirector10% Owner
Officer (give title below)Other (specify below)
1. Name and Address of Reporting Person*
BAKER JULIAN
(Last)(First)(Middle)
860 WASHINGTON STREET, 3RD FLOOR
(Street)
NEW YORK NEW YORK 10014
(City)(State)(Zip)
UNITED STATES
(Country)
Relationship of Reporting Person(s) to Issuer
XDirector10% Owner
Officer (give title below)Other (specify below)
Explanation of Responses:
1. Includes 67,000 non-qualified stock options ("Stock Options") exercisable solely into common stock ("Common Stock") of TScan Therapeutics, Inc. (the "Issuer") granted by the Issuer to Dr. Stephen R. Biggar, a full-time employee of Baker Bros. Advisors LP (the "Adviser"), on May 20, 2026, in his capacity as a director of the Issuer, pursuant to the Issuer's Amended and Restated 2021 Equity Incentive Plan (the "Incentive Plan"). The Stock Options have a strike price of $0.9946 per share, and vest on the earlier of the first anniversary of the grant date or the date of the next annual meeting of stockholders of the Issuer, subject to Dr. Biggar's continued service on the board of directors of the Issuer (the "Board") through the vesting date. The Stock Options expire on May 19, 2036.
2. Dr. Biggar serves on the Board as a representative of 667, L.P. ("667") and Baker Brothers Life Sciences, L.P. ("Life Sciences", and together with 667, the "Funds") and their affiliates and control persons.
3. After giving effect to the transaction reported herein and as a result of their ownership interest in (i) Baker Biotech Capital, L.P. and (ii) 667, Julian C. Baker and Felix J. Baker each may be deemed to have an indirect pecuniary interest in the Stock Options reported in column 9 of Table II held for the benefit of 667, a limited partnership of which the sole general partner is Baker Biotech Capital, L.P., a limited partnership of which the sole general partner is Baker Biotech Capital (GP), LLC, due to their interest in 667 and Baker Biotech Capital, L.P.'s right to receive an allocation of a portion of the profits from 667.
4. The Adviser serves as the investment adviser to the Funds. In connection with the services provided by the Adviser, the Adviser receives an asset-based management fee that does not confer any pecuniary interest in the securities held for the benefit of the Funds. Baker Bros. Advisors (GP) LLC ("the Adviser GP") is the Adviser's sole general partner. Julian C. Baker and Felix J. Baker are managing members of the Adviser GP. The Adviser has complete and unlimited discretion and authority with respect to the investment and voting power of the securities held for the benefit of the Funds. The general partners of the Funds relinquished to the Adviser all discretion and authority with respect to the investment and voting power of the securities held for the benefit of the Funds.
5. Julian C. Baker, Felix J. Baker, the Adviser GP and the Adviser disclaim beneficial ownership of the securities held for the benefit of the Funds except to the extent of their pecuniary interest therein, and this report shall not be deemed an admission that any of Julian C. Baker, Felix J. Baker, the Adviser GP or the Adviser is a beneficial owner of such securities for purposes of Section 16 or any other purpose.
6. Pursuant to the policies of the Adviser, Dr. Biggar does not have a right to any of the Issuer's securities issued as compensation for his service on the Board and the Funds are entitled to an indirect proportionate pecuniary interest in such securities. The Funds each own an indirect proportionate pecuniary interest in such securities. Solely as a result of their ownership interest in (i) the general partners of the Funds and (ii) the Funds, Felix J. Baker and Julian C. Baker may be deemed to have an indirect pecuniary interest in the shares of Common Stock, Stock Options and Common Stock issued upon exercise of Stock Options (i.e. no direct pecuniary interest) issued as compensation for such Board service.
7. Pursuant to the policies of the Adviser, the Adviser has voting and dispositive power over the Stock Options and any Common Stock received as a result of the exercise of Stock Options.
8. The acquisition of Stock Options reported on this form represents a single grant to Dr. Biggar of 67,000 Stock Options on Table II. This grant of 67,000 Stock Options for Dr. Biggar is reported for each of the Funds as each has an indirect pecuniary interest in such securities.
9. After giving effect to the transaction reported herein and as a result of their ownership interest in (i) Baker Brothers Life Sciences Capital, L.P. and (ii) Life Sciences, Julian C. Baker and Felix J. Baker each may be deemed to have an indirect pecuniary interest in the Stock Options reported in column 9 of Table II held for the benefit of Life Sciences, a limited partnership of which the sole general partner is Baker Brothers Life Sciences Capital, L.P., a limited partnership of which the sole general partner is Baker Brothers Life Sciences Capital (GP), LLC, due to their interest in Life Sciences and Baker Brothers Life Sciences Capital, L.P.'s right to receive an allocation of a portion of the profits from Life Sciences.
Remarks:
Dr. Stephen R. Biggar, a full-time employee of Baker Bros. Advisors LP, is a director of TScan Therapeutics, Inc. (the "Issuer"). By virtue of their representation on the board of directors of the Issuer, for purposes of Section 16 of the Securities Exchange Act of 1934, as amended, the reporting persons are deemed directors by deputization of the Issuer.
By: Baker Bros. Advisors LP, Name: Scott L. Lessing, Title: President /s/ Scott L. Lessing05/22/2026
Baker Bros. Advisors LP, Mgmt. Co. and Inv. Adviser to 667, L.P., pursuant to authority granted by Baker Biotech Capital, L.P., GP to 667, L.P. Name: Scott L. Lessing, Title: President /s/ Scott L. Lessing05/22/2026
/s/ Julian C. Baker05/22/2026
/s/ Felix J. Baker05/22/2026
By: Baker Bros. Advisors (GP) LLC, Name: Scott L. Lessing, Title: President /s/ Scott L. Lessing05/22/2026
Baker Bros. Advisors LP, Mgmt. Co. and Inv. Adviser to BAKER BROTHERS LIFE SCIENCES, L.P., pursuant to authority granted by Baker Brothers Life Sciences Capital, L.P., GP to Baker Brothers Life Sciences, L.P., Name: Scott L. Lessing, Title: President /s/05/22/2026
** Signature of Reporting PersonDate
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)

Source: View Original Filing on SEC EDGAR

FAQ

What insider transaction did TScan Therapeutics (TCRX) report on this Form 4?

TScan Therapeutics reported an award of 67,000 non-qualified stock options tied to its common stock. The grant was made to director Dr. Stephen R. Biggar as compensation for board service, with indirect pecuniary interests attributed to Baker-related investment funds.

What are the key terms of the 67,000 stock options reported for TScan Therapeutics (TCRX)?

The 67,000 non-qualified stock options have a strike price of $0.9946 per share and expire on May 19, 2036. They are exercisable solely into TScan common stock and were granted under the company’s Amended and Restated 2021 Equity Incentive Plan.

When do the new TScan Therapeutics (TCRX) director stock options vest?

The options vest on the earlier of the first anniversary of the May 20, 2026 grant date or the date of TScan’s next annual stockholder meeting. Vesting is conditioned on Dr. Stephen R. Biggar’s continued service on the company’s board of directors.

How are Baker Bros.-affiliated entities involved in the TScan Therapeutics (TCRX) option grant?

Dr. Biggar serves on the board as a representative of 667, L.P. and Baker Brothers Life Sciences LP. Under their policies, he has no right to the compensation securities; the funds hold an indirect proportionate pecuniary interest, while Baker-affiliated entities disclaim broader beneficial ownership.

Who has voting and dispositive power over the TScan Therapeutics (TCRX) stock options?

Baker Bros. Advisors LP, the investment adviser to the funds, has voting and dispositive power over the stock options and any common shares issued upon exercise. The funds’ general partners have relinquished discretion and authority over investment and voting power to the adviser.