European oncologists have had high exposure to biosimilars compared with other European specialists owing to the availability of epoetin alfa and filgrastim biosimilars. Although no biosimilars are available in the United States, we expect the first biosimilar that launches in the country to be Sandoz’s filgrastim, which was accepted for filing by the FDA in July 2014. While the arrival of biosimilars in the U.S. market will be a landmark event, a significantly greater commercial opportunity lies in the development of biosimilar monoclonal antibodies (MAbs). Roche’s hugely successful portfolio of MAbs provides a highly attractive target for biosimilar developers, and, unsurprisingly, the pipeline is rich with biosimilar rituximab, trastuzumab, and bevacizumab projects. Nevertheless, a major threat to biosimilar developers is the advent of new, improved biologics, which could supersede current standards of care, thereby reducing the opportunity available to biosimilar versions of currently prescribed biologics. We surveyed oncologists in the United States and Europe to gain insight into key topics such as perception of similarity between biosimilars and reference brands, influence of biosimilar price on uptake, current and future expectations for biologic reimbursement, automatic substitution, indication extrapolation, and their willingness to use next-generation biologics. Our primary research helps inform our market forecasts for biosimilars in oncology across the seven major pharmaceutical markets.