Reuters reported that Merck hopes to patent subcutaneous formulations of Keytruda® (pembrolizumab). Merck has several studies evaluating subcutaneous pembrolizumab planned or underway, according to a search of clinicaltrials.gov and a previous press release. A subcutaneous formulation may be more convenient for patients and healthcare providers, and therefore has the potential to replace the current infusion regime in many settings. Reuters reported that Merck CFO Caroline Litchfield stated that Merck believes such a formulation would be patentable, which could mean Merck’s patent protection for its blockbuster is extended for a considerable period of time. The report states that Merck is anticipating biosimilar competition for the infusion product by 2028.