Mercy BioAnalytics, a cancer early detection firm based in Waltham, Massachusetts, closed a $59 million Series B to fund commercialization of its blood-based ovarian cancer screening test slated for early 2026. The company plans an early access program in Boston, expanding to other metros. Its Halo platform measures tumor-associated proteins on extracellular vesicles with high specificity using proximity ligation assays. Mercy is also developing a lung cancer screening assay to be combined with the ovarian test. This financing bolsters the company’s position in the growing liquid biopsy cancer detection market.