BioTheryX has dosed the first participant in the Phase I clinical trial of its oral therapy BTX-1188 to treat advanced hematologic and solid tumour malignancies.

The orally bioavailable BTX-1188 is a dual target protein degrader, which is designed to degrade validated oncology targets GSPT1 and IKZF1/3.

The open label, multicentre, sequential dose escalation, non-randomised clinical trial will evaluate the pharmacokinetics, preliminary efficacy and safety of BTX-1188 in advanced lymphoid, acute myeloid leukemia and solid tumour patients.

The study will evaluate the candidate in patients who have failed standard treatment.

BioTheryX president and CEO Philippe Drouet said: “BTX-1188 is one of many potential best-in-class protein degrader candidates our team has designed and developed leveraging our distinctive PRODEGY targeted protein degradation platform to provide new treatment approaches for people living with cancer and other diseases.

“With our clinical trial site partners, we are working as expeditiously as possible to study BTX-1188 and validate the potential of our platform.”

To determine a recommended Phase II study dose of BTX-1188 in subjects will be the Phase I study’s primary objective.

The recommended dose will be used in expansion cohorts where BTX-1188’s safety and efficacy will be assessed in hematologic and solid tumour malignancies.

In preclinical models, BTX-1188 showed deep, durable, and rapid degradation of GSPT1 and IKZF1/3 targets at low nanomolar concentrations.

In January 2020, BioTheryX commenced patient dosing in a Phase I study of small molecule, oral multi-kinase inhibitor, BTX-A51, to treat relapsed/refractory acute myeloid leukaemia.

The trial evaluated the safety, pharmacokinetics and tolerability of BTX-A51 in relapsed/refractory acute myeloid leukaemia patients.