NEW YORK – Byondis said on Monday that it has submitted a marketing authorization application to the European Medicines Agency (EMA) for its investigational antibody-drug conjugate trastuzumab duocarmazine for advanced HER2-positive breast cancer.
Nijmegen, Netherlands-based Byondis is developing trastuzumab duocarmazine, also known as SYD985, in partnership with Wedel, Germany-based Medac. Under a licensing deal struck earlier this year, Medac has exclusive rights to market the antibody-drug conjugate in European countries should the agent garner marketing authorization.
The application, which the EMA has accepted and will now review, includes data from the Phase III TULIP trial, in which previously treated HER2-positive, unresectable, locally advanced, or metastatic breast cancer patients on SYD985 derived greater progression-free survival benefit compared to those on physician's choice of treatment. According to Byondis, TULIP also demonstrated SYD985 had an overall survival benefit as a secondary endpoint.
The US Food and Drug Administration is also reviewing an application for SYD985 in this patient population, and has granted the drug fast track designation. Meanwhile, Medac is preparing an application for the drug in this setting for the UK Medicines and Healthcare Products Regulatory Agency (MHRA).
If approved, SYD985 would compete with other antibody-drug conjugates on the market for metastatic HER2-positive breast cancer, including AstraZeneca and Daiichi Sankyo's Enhertu (trastuzumab deruxtecan). Byondis has boasted that its drug is designed to release its cytotoxic payload to neighboring tumor cells, including those with lower HER2 expression. The drug is also highly stable while circulating in the bloodstream, which Byondis claims could limit the amount of payload released prematurely before the drug makes it to the tumor.
Enhertu recently showed activity in HER2-low advanced breast cancer patients through the so-called "bystander effect" in the DESTINY-Breast-4 trial. AstraZeneca and Daiichi Sankyo have said they plan to bring this data to regulators around the world and seek approval for the drug in this setting.