The spate of M&A deals in the pharma sector seems to never stop. A few hours ago, before Asian stock markets’ closing bell, Japan-based Otsuka Pharmaceutical informed investors and analysts that it had acquired Visterra for $430m. Visterra is a clinical-stage biotech company headquartered in Cambridge, Massachusetts, and focused on antibody-based therapies aimed at treating acute infections. Visterra has two main assets: VIS410, a Phase-II treatment based on monoclonal antibody for influenza A, and Dengue treatment VIS513, which should be clinically tested in a Phase-I trial starting H2 2018. Visterra’s investors include Bill & Melinda Gates Foundation, MRL Ventures Fund, Vertex Venture Holdings Ltd., and Polaris Partners.