One Biosciences, a spin-off of Institut Curie, secures €3.3 million to develop the first single-cell diagnostic for triple-negative breast cancer

Triple-negative breast cancer (TNBC) represents approximately 15–20% of breast cancer cases. Patients face high relapse rates, rapid disease progression and limited treatment options, while clinicians still lack reliable biomarkers to predict which patients will respond to immunotherapy or chemotherapy combinations. Current diagnostic approaches average signals across millions of cells, masking the tumor heterogeneity that drives resistance and treatment failure.

The CAST project, led by One Biosciences, in partnership with Institut Curie, aims to overcome these limitations. This four-year program seeks to bring OneMapTM, One Biosciences’ cutting-edge solution, to market as the first single-cell diagnostic platform designed to guide treatment decisions for patients with TNBC, commercialized as an in vitro diagnostic test.

Co-founded in 2020 by Institut Curie and Home Biosciences, One Biosciences specializes in precision oncology. Born out of the research of Dr. Céline Vallot, CNRS research director and head of the Dynamics of epigenetic plasticity in cancer team at Institut Curie, the start-up leverages single-cell profiling to improve cancer diagnosis and guide therapeutic decision-making.

OneMap™, single-cell technologies and AI at the service of therapeutic decision-making

OneMapTM combines single-cell transcriptomics and AI to analyze tumors at the resolution of individual cells and deliver clinically actionable reports within two weeks directly from standard hospital biopsies. By deciphering tumor heterogeneity at single-cell resolution and identifying the specific cell populations that may drive treatment resistance, this platform could enable clinicians to make more informed treatment decisions for each patient.

Initial studies conducted jointly by One Biosciences and Institut Curie have already demonstrated the ability to generate high-quality single-cell data from routine TNBC biopsies and identify cellular signatures associated with response to immunotherapy. CAST will further build on Institut Curie’s unique clinical expertise and its Institute of Women’s Cancers, co-founded with PSL university and INSERM, providing access to a cohort of more than 300 TNBC patients. This project is expected to become the world’s largest clinically annotated single-cell dataset in triple-negative breast cancer.

Supported by €3.3 million in funding the under the fifth 2026 i-Démo call for projects as part of the France 2030 initiative, the CAST program will focus on four key areas: industrializing the OneMap™ platform, validating predictive biomarkers in TNBC, preparing for regulatory approval, and scaling One Biosciences’ centralized clinical laboratory infrastructure in the Paris region to enable future commercial deployment.

“This funding is a defining milestone for One Biosciences and the progression of single cell technology into the clinic,” said Hedi Ben Brahim, CEO of One Biosciences. “CAST accelerates the path from breakthrough science to a scalable commercial product that can help oncologists make better treatment decisions for patients. We are very grateful to France 2030 for their transforming support.”

“CAST perfectly reflects Institut Curie’s mission: transforming cutting-edge research into tangible benefits for patients,” said Dr. Céline Vallot, co-founder & chief scientific officer of One Biosciences. “By bringing single-cell technologies into clinical practice, we have the opportunity to fundamentally improve the treatment of aggressive cancers. This approach helps ensure that every patient receives the treatment best suited to the unique biology of their disease, ultimately improving outcome and quality of life.”

“Triple-negative breast cancer remains one of the hardest breast cancers to treat because we still lack robust tools to predict response and resistance,” added Dr. Luc Cabel, medical oncologist at Institut Curie and principal investigator of the CAST project. “The medical need is to desescalate treatment for good responders to limit the side effects and to better chose a salvage treatment for bad responders. By combining clinical expertise with single-cell and AI technologies, CAST has the potential to give oncologists a much more precise understanding of each patient’s tumor and ultimately improve treatment decisions and outcomes.”

By bridging the gap between research and clinical deployment, the CAST project represents a major step toward making single-cell precision oncology a reality for patients.