Form 8-K

8-K — BICYCLE THERAPEUTICS PLC

Accession: 0001104659-26-099221

Filed: 2026-08-20

Period: 2026-08-18

CIK: 0001761612

SIC: 2834 (PHARMACEUTICAL PREPARATIONS)

Item: Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers: Compensatory Arrangements of Certain Officers

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UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section

13 or 15(d) of the Securities Exchange Act of 1934

August 18, 2026

Date of Report (Date of earliest event reported)

Bicycle

Therapeutics plc

(Exact name of registrant as specified in its

charter)

England

and Wales

001-38916

Not

applicable

(State or other jurisdiction

of incorporation)

(Commission

File Number)

(IRS Employer

Identification No.)

Blocks

A & B, Portway Building,

Granta

Park Great Abington, Cambridge

United Kingdom

CB21

6GS

(Address of principal

executive offices)

(Zip Code)

Registrant’s telephone number, including area code: +44

1223 261503

Check the appropriate box below if the Form 8-K

filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

¨ Written

communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

¨ Soliciting

material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

¨ Pre-commencement

communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

¨ Pre-commencement

communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b)

of the Act:

Title

of each class

Trading

Symbol (s)

Name

of each exchange on which registered

Ordinary

shares, nominal value £0.01 per share

n/a

The

Nasdaq

Stock Market LLC*

American

Depositary Shares, each representing one ordinary share, nominal value £0.01 per share

BCYC

The

Nasdaq

Stock Market LLC

* Not

for trading, but only in connection with the listing of the American Depositary Shares on The Nasdaq Stock Market LLC.

Indicate

by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§ 230.405

of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§ 240.12b-2 of this chapter).

Emerging growth company ¨

If an emerging

growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any

new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ¨

Item 5.02. Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of

Certain Officers.

On August 18, 2026, Charles Swanton resigned as a Class II director of the Board of Directors (the “Board”) of Bicycle Therapeutics

plc (the “Company”), as a member of the Board’s committees and as a member of the Company’s Clinical Advisory Board, effective

immediately. Dr. Swanton’s resignation was for personal reasons and not the result of any disagreement with the Company on any matter

relating to the Company’s operations, policies or practices.

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934,

the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

Date: August 20, 2026

BICYCLE THERAPEUTICS PLC

By:

/s/ Travis Thompson

Name:

Travis Thompson

Title:

Chief Financial Officer

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