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Table of Contents ( Mark One ) ☑ UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington , D.C. 20549 FORM 10 - K ANNUAL REPORT PURSUANT TO SECTION 13 OR 15 ( d ) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31 , 2020 . OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15 ( d ) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file number 001-38916 BICYCLE THERAPEUTICS PLC ( Exact name of registrant as specified in its charter ) England and Wales ( State or Other Jurisdiction of Incorporation or Organization ) B900 , Babraham Research Campus Cambridge , United Kingdom ( Address of Principal Executive Offices ) Not Applicable ( I.R.S. Employer Identification No. ) CB22 3AT ( Zip Code ) Registrant's telephone number , including area code +44 1223 261503 Title of each class Securities registered pursuant to Section 12 ( b ) of the Act : Name of each exchange on which registered Ordinary shares , nominal value £ 0.01 per share * American Depositary Shares , each representing one ordinary share , nominal value £ 0.01 per share Trading Symbol ( s ) n / a BCYC The Nasdaq Stock Market LLC The Nasdaq Stock Market LLC * Not for trading , but only in connection with the listing of the American Depositary Shares on the NASDAQ Global Select Market . Indicate by check mark if the registrant is a well - known seasoned issuer , as defined in Rule 405 of the Securities Act . Yes No ☑ Indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or Section 15 ( d ) of the Act . Yes ☐ No ☑ Indicate by check mark whether the registrant ( 1 ) has filed all reports required to be filed by Section 13 or 15 ( d ) of the Securities Exchange Act of 1934 during the preceding 12 months ( or for such shorter period that the registrant was required to file such reports ) , and ( 2 ) has been subject to such filing requirements for the past 90 days . Yes > No ☐ Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S - T during the preceding 12 months ( or for such shorter period that the registrant was required to submit such files ) . Yes ☑No ☐ Indicate by check mark whether the registrant is a large accelerated filer , an accelerated filer , a non - accelerated filer , a smaller reporting company , or an emerging growth company . See the definitions of " large accelerated filer , " " accelerated filer " , " smaller reporting company " and " emerging growth company " in Rule 12b - 2 of the Exchange Act . Large accelerated filer Non - accelerated filer ☑ Accelerated filer ☐ Smaller reporting company ☑ 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 . ☑ Indicate by check mark whether the registrant has filed a report on and attestation to its management's assessment of the effectiveness of its internal control over financial reporting under Section 404 ( b ) of the Sarbanes - Oxley Act ( 15 U.S.C. 7262 ( b ) ) by the registered public accounting firm that prepared or issued its audit report . ☐ Indicate by check mark whether the registrant is a shell company ( as defined in Rule 12b - 2 of the Exchange Act ) . Yes No ☑ The aggregate market value ( approximate ) of the registrant's voting and non - voting common equity held by non - affiliates based on the closing price per American Depositary Share , or ADS , of the registrant's ADSs on The Nasdaq Global Select Market on June 30 , 2020 ( the last business day of the registrant's most recently completed second fiscal quarter ) was $ 189,962,881 . As of March 5 , 2021 , the registrant had 23,090,382 ordinary shares , nominal value £ 0.01 per share , outstanding . Documents Incorporated by Reference : Portions of the registrant's definitive proxy statement , or Proxy Statement , for its 2021 Annual General Meeting , which the registrant intends to file pursuant to Regulation 14A with the Securities and Exchange Commission not later than 120 days after the registrant's fiscal year ended December 31 , 2020 , are incorporated by reference into Part III of this Annual Report on Form 10 - K .