Bicycle Therapeutics to Present Trials in Progress Poster for BT5528 at the 2020 American Society of Clinical Oncology Virtual Meeting

Bicycle Therapeutics plc (NASDAQ: BCYC), a biotechnology company pioneering a new and differentiated class of therapeutics based on its proprietary bicyclic peptide (Bicycle®) technology, today announced that a poster describing the design of the ongoing Phase I/II trial of BT5528 will be presented during an e-poster session at the American Society of Clinical Oncology (ASCO) 2020 Virtual Scientific Program on May 29-31, 2020. BT5528 is a second-generation Bicycle Toxin Conjugate (BTC) that targets EphA2, a tumor antigen that is overexpressed in a wide range of solid tumor types and is associated with poor outcomes.

"To our knowledge, BT5528 is one of a very few toxin conjugates that target EphA2 currently being evaluated in clinical studies, despite literature indicating that EphA2 is an attractive target for selective payload delivery," said Kevin Lee, Ph.D., Chief Executive Officer of Bicycle Therapeutics. "Other EphA2-targeting toxin conjugates using biologics have been investigated but ultimately discontinued due to poor tolerability. Leveraging the unique features of Bicycles, we designed BT5528 to have a pharmacokinetic profile that could allow it to circumvent limitations of prior, unsuccessful efforts to target EphA2. We recently announced that, to date, doses of BT5528 administered in the ongoing Phase I/II trial in patients with advanced solid tumors associated with EphA2 expression continue to appear well-tolerated with manageable adverse events as dosing nears clinically relevant levels. We are excited by the progress we're making in the trial and look forward to discussing its design at ASCO."

Details on Bicycle's poster presentation at ASCO are as follows:

Session Title: Developmental Therapeutics?Molecularly Targeted Agents and Tumor Biology Session
Poster Title: BT5528-100 phase I/II study of the safety, pharmacokinetics, and preliminary clinical activity of BT5528 in patients with advanced malignancies associated with EphA2 expression
Abstract #: TPS3655
Session Date and Time: Friday, May 29, 2020 at 8:00 a.m. ET

The poster will be available on the Publications section of bicycletherapeutics.com following presentation.

About Bicycle Therapeutics
Bicycle Therapeutics (NASDAQ: BCYC) is a clinical-stage biopharmaceutical company developing a novel class of medicines, referred to as Bicycles®, for diseases that are underserved by existing therapeutics. Bicycles are fully synthetic short peptides constrained with small molecule scaffolds to form two loops that stabilize their structural geometry. This constraint facilitates target binding with high affinity and selectivity, making Bicycles attractive candidates for drug development. Bicycle's lead product candidate, BT1718, a Bicycle Toxin Conjugate (BTC) that targets MT1-MMP, is being investigated in an ongoing Phase I/IIa clinical trial in collaboration with the Centre for Drug Development of Cancer Research UK. Bicycle is also evaluating BT5528, a second-generation BTC targeting EphA2, in a Company-sponsored Phase I/II study. Bicycle is headquartered in Cambridge, UK with many key functions and members of its leadership team located in Lexington, MA. For more information, visit bicycletherapeutics.com.

Forward Looking Statements
This press release may contain forward-looking statements made pursuant to the safe harbor provisions of the Private Securities Litigation Reform Act of 1995. These statements may be identified by words such as "aims," "anticipates," "believes," "could," "estimates," "expects," "forecasts," "goal," "intends," "may," "plans," "possible," "potential," "seeks," "will" and variations of these words or similar expressions that are intended to identify forward-looking statements, although not all forward-looking statements contain these words. Forward-looking statements in this press release include, but are not limited to, statements regarding the clinical development of BT5528 or any of Bicycle's other product candidates or programs; the design of Bicycle's clinical trials; the safety, durability or efficacy of BT5528; and the potential benefits of BT5528 or any of Bicycle's other product candidates. Bicycle may not actually achieve the plans, intentions or expectations disclosed in these forward-looking statements, and you should not place undue reliance on these forward-looking statements. Actual results or events could differ materially from the plans, intentions and expectations disclosed in these forward-looking statements as a result of various factors, including: uncertainties inherent in the initiation and completion of preclinical studies and clinical trials and clinical development of Bicycle's product candidates; availability and timing of results from preclinical studies and clinical trials; whether initial or interim results from a clinical trial will be predictive of the final results of the trial or the results of future trials; the risk that trials and studies may be delayed and may not have satisfactory outcomes; expectations for regulatory approvals to conduct trials or to market product; risks to site initiation, clinical trial commencement, patient enrollment and follow-up, as well as to Bicycle's abilities to meet other anticipated deadlines and milestones, presented by the ongoing COVID-19 pandemic; and other important factors, any of which could cause our actual results to differ from those contained in the forward-looking statements, are described in greater detail in the section entitled "Risk Factors" in Bicycle's Quarterly Report on Form 10-Q filed with the Securities and Exchange Commission (SEC) on May 7, 2020, as well as in other filings Bicycle may make with the SEC in the future. Any forward-looking statements contained in this press release speak only as of the date hereof, and Bicycle expressly disclaims any obligation to update any forward-looking statements contained herein, whether as a result of any new information, future events, changed circumstances or otherwise, except as otherwise required by law.