Typically R&D is divided into Discovery and Development. These can be individual divisions each with a head that reports to the head of R&D.
Occasionally a company may determine that a particular Therapy Area would benefit from uniting both Discovery and Development organizations under one business unit. Some example could be Oncology, or Neurosciences. Some companies devote special attention to certain technologies by focusing the technology into a Business Unit, e.g. Biologics, or Gene Therapy. In the early days of biotechnology such focus made sense. But as we describe in the section Small Molecule, Peptide and Protein-Based Drugs we argue that the tools of molecular biology are now widespread and most therapy areas are amenable to a protein-based approach that protein-based drugs don’t require such separation.