Merck & Company Inc. Merck makes pharmaceutical products to treat several conditions in a number of therapeutic areas, including cardiometabolic disease, cancer, and infections. Within cancer, the firm's immuno-oncology platform, led by Keytruda, is a major contributor to overall sales. The company also has a substantial vaccine business aimed at preventing pediatric diseases, as well as Gardasil for human papillomavirus. Additionally, Merck sells animal health-related drugs. From a geographical perspective, 47% of the company's sales are generated from US human health (pharmaceuticals and vaccines).