Dren Bio, Inc., a company developing powerful protein-engineering technologies for depletion of cells, protein aggregates and other disease-causing agents, announced the closing of a $60 million Series A investment round. The round was led by SR One and Taiho Ventures, LLC , with participation from existing investors 8VC and Mission BioCapital and new investors including BVF Partners L.P., HBM Healthcare Investments, and Alexandria Venture Investments.