BAKER BROS. ADVISORS LP - 02 Jan 2026 Form 4 Insider Report for BICYCLE THERAPEUTICS PLC (BCYC)

Reporting relationship: Director, 10%+ Owner
Issuer ticker: BCYC
Reported as of: 02 Jan 2026
Net transaction value: $0
SEC form: 4
Accepted by SEC: 06 Jan 2026, 17:41:23 UTC
Prior SEC filing: 05 Jan 2026
Next SEC filing: 14 Jan 2026
Source filing: View source filing
Reporting owner signature: By: Baker Bros. Advisors LP, Name: Scott L. Lessing, Title: President /s/ Scott L. Lessing

Key filing fact

BAKER BROS. ADVISORS LP filed Form 4 for BICYCLE THERAPEUTICS PLC (BCYC) on 06 Jan 2026.

Key facts

This page summarizes BAKER BROS. ADVISORS LP's Form 4 filing for BICYCLE THERAPEUTICS PLC (BCYC).
4 reported transactions and 2 derivative rows are listed below.
Accepted by SEC: 06 Jan 2026, 17:41.

Change

Previous filing in this sequence was filed on 05 Jan 2026.
Current net transaction value: $0.

Research use

This tells you what this filing adds before you inspect full transaction and derivative tables.
You can trace every row back to the original SEC filing document.

Evidence

Filed on Form 4

Ownership activity is grounded in SEC Form 4 disclosures.

View source filing

Reporting Owners (6)

CIK 0001263508 Primary reporting owner

BAKER BROS. ADVISORS LP

Relationship: Director, 10%+ Owner
Address: 860 WASHINGTON STREET, 3RD FLOOR, NEW YORK
Signature: By: Baker Bros. Advisors LP, Name: Scott L. Lessing, Title: President /s/ Scott L. Lessing
Signature date: 06 Jan 2026

CIK 0001551139

667, L.P.

Relationship: Director, 10%+ Owner
Address: 860 WASHINGTON STREET, 3RD FLOOR, NEW YORK
Signature: 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
Signature date: 06 Jan 2026

CIK 0001580575

Baker Bros. Advisors (GP) LLC

Relationship: Director, 10%+ Owner
Address: 860 WASHINGTON STREET, 3RD FLOOR, NEW YORK
Signature: By: Baker Bros. Advisors (GP) LLC, Name: Scott L. Lessing, Title: President /s/ Scott L. Lessing
Signature date: 06 Jan 2026

CIK 0001363364

Baker Brothers Life Sciences LP

Relationship: Director, 10%+ Owner
Address: 860 WASHINGTON STREET, 3RD FLOOR, NEW YORK
Signature: 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/
Signature date: 06 Jan 2026

CIK 0001087940

BAKER FELIX

Relationship: Director, 10%+ Owner
Address: 860 WASHINGTON STREET, 3RD FLOOR, NEW YORK
Signature: /s/ Felix J. Baker
Signature date: 06 Jan 2026

CIK 0001087939

BAKER JULIAN

Relationship: Director, 10%+ Owner
Address: 860 WASHINGTON STREET, 3RD FLOOR, NEW YORK
Signature: /s/ Julian C. Baker
Signature date: 06 Jan 2026

Reported non-derivative transactions

Shares, units, or other non-derivative securities reported in this filing.

BCYC transaction

American Depositary Shares

Award

Transaction value: $0
Shares: +19,000
Change %: +2.1%
Price: $0.000000
Shares after: 937,483
Date: 02 Jan 2026
Ownership: See Footnotes
Footnotes: F1, F2, F3, F4, F5, F6, F7, F8

BCYC transaction

American Depositary Shares

Award

Transaction value: $0
Shares: +19,000
Change %: +0.19%
Price: $0.000000
Shares after: 10,018,674
Date: 02 Jan 2026
Ownership: See Footnotes
Footnotes: F1, F2, F4, F5, F6, F7, F8, F9

Reported derivative securities

Options, warrants, convertible securities, or similar derivative positions disclosed in the filing.

BCYC transaction Derivative

Share Option (Right to Buy)

Award

Transaction value: $0
Shares: +38,000
Change %
Price: $0.000000
Shares after: 38,000
Date: 02 Jan 2026
Ownership: See Footnotes
Underlying class: American Depositary Shares
Underlying amount: 38,000
Exercise price: $7.08
Footnotes: F2, F3, F4, F5, F7, F8, F10, F11

BCYC transaction Derivative

Share Option (Right to Buy)

Award

Transaction value: $0
Shares: +38,000
Change %
Price: $0.000000
Shares after: 38,000
Date: 02 Jan 2026
Ownership: See Footnotes
Underlying class: American Depositary Shares
Underlying amount: 38,000
Exercise price: $7.08
Footnotes: F2, F4, F5, F7, F8, F9, F10, F11

^* marks a reported price that did not pass the local price check.

Additional SEC filing notes

Filing notes and footnotes

Explanation of responses 11 footnotes

Footnote F1

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.

Footnote F2

ADS each represent 1 Ordinary Share.

Footnote F3

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.

Footnote F4

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.

Footnote F5

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.

Footnote F6

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.

Footnote F7

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.

Footnote F8

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.

Footnote F9

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.

Footnote F10

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.

Footnote F11

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.

SEC 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.