By growing tumor twins from a simple blood draw
Sirius Neosight, a pioneering French start-up in functional liquid biopsy capable of growing a patient’s tumor cells directly from a blood draw to redevelop living replicas of their tumor, and the Centre Léon Bérard, a world-renowned oncology reference center based in Lyon, announce the official launch of the E-FACToR clinical study (Enumeration and Functional Analysis of Circulating Tumor Cells for Homologous Recombination). This prospective, single-center study, approved by the Sud-Est II Committee for the Protection of Persons in February 2026, marks a major step forward for functional personalized medicine applicable from a simple blood draw.
The E-FACToR study aims to better understand why some patients respond to treatments and others do not, in order to tailor therapies more precisely. Specifically, it seeks to establish whether a measurement taken on tumor cells collected from the blood — without a biopsy — can predict treatment efficacy. It will notably assess the correlation between the functional status of homologous recombination (HR), a key DNA repair mechanism on which sensitivity to PARP inhibitors depends, measured in circulating tumor cells (CTCs) and progression-free survival (PFS) in patients treated with PARP inhibitors and/or platinum-based chemotherapy. It will involve 300 patients with advanced or metastatic breast, prostate, ovarian, and pancreatic cancers, followed at the Centre Léon Bérard.
