SEC FORM 4

SEC FORM 4 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

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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

10014

(City)

(State)

(Zip)

2. Issuer Name and Ticker or Trading Symbol
BICYCLE THERAPEUTICS PLC [ BCYC ]

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

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

3. Date of Earliest Transaction (Month/Day/Year)
01/02/2026

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

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

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

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)
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	Code	V	Amount	(A) or (D)	Price		6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
American Depositary Shares	01/02/2026		A		19,000⁽¹⁾	A	$0	937,483	I	See Footnotes⁽²⁾⁽³⁾⁽⁴⁾⁽⁵⁾⁽⁶⁾⁽⁷⁾⁽⁸⁾
American Depositary Shares	01/02/2026		A		19,000⁽¹⁾	A	$0	10,018,674	I	See Footnotes⁽²⁾⁽⁴⁾⁽⁵⁾⁽⁶⁾⁽⁷⁾⁽⁸⁾⁽⁹⁾

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)
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)	Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares	8. Price of Derivative Security (Instr. 5)		10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
Share Option (Right to Buy)	$7.08	01/02/2026		A		38,000⁽¹⁰⁾		⁽¹⁰⁾	01/02/2036	American Depositary Shares⁽²⁾⁽¹⁰⁾	38,000	$0	38,000	I	See Footnotes⁽³⁾⁽⁴⁾⁽⁵⁾⁽⁷⁾⁽⁸⁾⁽¹¹⁾
Share Option (Right to Buy)	$7.08	01/02/2026		A		38,000⁽¹⁰⁾		⁽¹⁰⁾	01/02/2036	American Depositary Shares⁽²⁾⁽¹⁰⁾	38,000	$0	38,000	I	See Footnotes⁽⁴⁾⁽⁵⁾⁽⁷⁾⁽⁸⁾⁽⁹⁾⁽¹¹⁾

1. Name and Address of Reporting Person^*

BAKER BROS. ADVISORS LP

(Last)

(First)

(Middle)

860 WASHINGTON STREET, 3RD FLOOR

(Street)

NEW YORK

10014

(City)

(State)

(Zip)

Relationship of Reporting Person(s) to Issuer

X	Director	X	10% 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

10014

(City)

(State)

(Zip)

Relationship of Reporting Person(s) to Issuer

X	Director	X	10% 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

10014

(City)

(State)

(Zip)

Relationship of Reporting Person(s) to Issuer

X	Director	X	10% 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

10014

(City)

(State)

(Zip)

Relationship of Reporting Person(s) to Issuer

X	Director	X	10% 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

10014

(City)

(State)

(Zip)

Relationship of Reporting Person(s) to Issuer

X	Director	X	10% 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

10014

(City)

(State)

(Zip)

Relationship of Reporting Person(s) to Issuer

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

Explanation of Responses:

1. Includes 19,000 restricted share units (each an "RSU") payable in American Depositary Shares ("ADS") or Ordinary Shares ("Ordinary Shares") at the option of Bicycle Therapeutics plc (the "Issuer") granted by the Issuer to Felix J. Baker, a managing member of Baker Bros. Advisors (GP) LLC (the "Adviser GP") on January 2, 2026 pursuant to the Issuer's 2020 Equity Incentive Plan (the "2020 Plan"). The RSUs vest in four equal quarterly installments on March 15, 2026, June 15, 2026, September 15, 2026 and December 15, 2026, subject to Felix J. Baker's continuous service on the board of directors of the Issuer (the "Board") through such vesting dates. Felix J. Baker 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"). Each RSU represents a contingent right to receive one ADS or Ordinary Share.

2. ADS each represent 1 Ordinary Share.

3. After giving effect to the transactions 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 securities reported in column 5 of Table I and in column 9 of Table II directly held by or 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. Baker Bros. Advisors LP ("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 directly by or held for the benefit of the Funds. 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 directly by or 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 directly by or 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 directly by or 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. Includes beneficial ownership of 16,400 ADS issuable upon the vesting of RSUs payable in ADS or Ordinary Shares at the Issuer's option previously issued to Felix J. Baker, in his capacity as a director of the Issuer pursuant to the 2020 Plan of which the Funds may be deemed to own a portion. 8,400 of the RSUs previously granted are fully vested and the remaining 8,000 vest in two equal annual installments beginning on April 18, 2026, subject to Felix J. Baker's continuous service on the Board through the vesting date. Felix J. Baker serves on the Board as a representative of the Funds and their affiliates and control persons. Each RSU represents a contingent right to receive one Ordinary Share of the Issuer.

7. Pursuant to the policies of the Adviser, Felix J. Baker does not have any 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 the securities. The Funds each own an indirect proportionate pecuniary interest in the ADS or Ordinary Shares received upon vesting of RSUs and non-qualified share options exercisable into ADS or Ordinary Shares of the Issuer ("Share Options") received as a result of his service on the Board. 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 ADS or Ordinary Shares received upon vesting of RSUs, Share Options, and ADS or Ordinary Shares received upon the exercise of Share Options (i.e. no direct pecuniary interest) issued as compensation for such Board service.

8. The Adviser has voting and dispositive power over the Share Options, RSUs and any ADS or Ordinary Shares received as a result of the exercise of Share Options or vesting of RSUs.

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 may be deemed to have an indirect pecuniary interest in the securities reported in column 5 of Table I and in column 9 of Table II directly held by or 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.

10. Includes 38,000 Share Options granted by the Issuer to Felix J. Baker, in his capacity as a director of the Issuer pursuant to the 2020 Plan. The Share Options have a strike price of $7.08 and vest into ADS or Ordinary shares at the Issuer's option in four equal quarterly installments on March 15, 2026, June 15, 2026, September 15, 2026 and December 15, 2026, provided, however, that all vesting of Share Options granted to a director shall cease if that director resigns from the Board or otherwise ceases to serve as a director, unless the Board determines otherwise.

11. The acquisitions of the RSUs and Share Options reported on this form represent a single grant to Felix J. Baker of 19,000 RSUs on Table I and 38,000 Share Options on Table II. These grants, totaling 19,000 RSUs and 38,000 Share Options for Felix J. Baker, are reported for each of the Funds as each has an indirect pecuniary interest in such securities.

Remarks:

Felix J. Baker, a managing member of Baker Bros. Advisors (GP) LLC, the sole general partner of Baker Bros. Advisors LP, is a director of Bicycle Therapeutics plc (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 other than Felix J. Baker are deemed directors by deputization of the Issuer.

	By: Baker Bros. Advisors LP, Name: Scott L. Lessing, Title: President /s/ Scott L. Lessing	01/06/2026
	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. Lessing	01/06/2026
	By: Baker Bros. Advisors (GP) LLC, Name: Scott L. Lessing, Title: President /s/ Scott L. Lessing	01/06/2026
	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/	01/06/2026
	/s/ Felix J. Baker	01/06/2026
	/s/ Julian C. Baker	01/06/2026
	** 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.

Director Baker Bros. Advisors Lp was granted 38,000 units of American Depositary Shares (SEC Form 4)