Bicycle Therapeutics Announces First Patient Dosed in Phase I/II Trial of Bicycle Toxin Conjugate BT5528 in Patients with Advanced Solid Tumors

Bicycle Therapeutics plc (NASDAQ: BCYC) a clinical-stage biotechnology company pioneering a new and differentiated class of therapeutics based on its proprietary bicyclic peptide (Bicycles) technology, today announced that the first patient has been dosed in the Phase I dose escalation of its Phase I/II study of BT5528, a Bicycle Toxin Conjugate (BTC) targeting tumor antigen EphA2, in patients with advanced solid tumors associated with EphA2 expression. BT5528 is a second-generation BTC, which uses a valine-citrulline cleavable linker and a cytotoxin MMAE payload.

“The initiation of this trial is an important step for Bicycle as BT5528 is our first U.S. investigational new drug (IND), and this is the first clinical study to be sponsored by the Company,” said Kevin Lee, Ph.D., Chief Executive Officer of Bicycle Therapeutics. “BT5528 is also the first of our second-generation BTCs to enter the clinic and has demonstrated promising anti-tumor activity and tolerability across a broad range of preclinical studies. Notably, unlike existing EphA2-targeting antibody drug conjugates, BT5528 did not show coagulopathy in preclinical studies, and the first clinical dose has been well tolerated. We are pleased to have achieved another milestone in progressing our pipeline based on our novel and differentiated Bicycle technology, which we believe could generate potential first-in-class treatment options for patients suffering from cancer and other serious diseases.”

The Phase I/II multi-center, open-label trial will evaluate BT5528 administered once-weekly as a single agent and in combination with nivolumab. The Phase I portion is a dose escalation primarily designed to assess the safety and tolerability of BT5528 and to determine a recommended Phase II dose (RP2D). Following selection of an RP2D, a Phase II dose expansion portion will be initiated with the primary objective of evaluating the clinical activity of BT5528. The study will be conducted across sites in the U.S. and the UK.

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.