Pfizer Inc. announced today the discontinuation of the global clinical development program for bococizumab, its investigational Proprotein Convertase Subtilisin Kexin type 9 inhibitor (PCSK9i). The totality of clinical information now available for bococizumab, taken together with the evolving treatment and market landscape for lipid-lowering agents, indicates that bococizumab is not likely to provide value to patients, physicians, or shareholders. As a result, Pfizer has decided to discontinue the development program, including the two ongoing cardiovascular outcome studies. With the completion of six bococizumab lipid-lowering studies, Pfizer has observed an emerging clinical profile that includes an unanticipated attenuation of low-density lipoprotein cholesterol (LDL-C) lowering over time, as well as a higher level of immunogenicity and higher rate of injection-site reactions with bococizumab than shown with the other agents in this class. The goal of treating elevated cholesterol is to reduce the occurrence of cardiovascular events such as heart attacks and stroke, which requires long-term effective and durable cholesterol-lowering. "As a company, we understand that developing new and important medicines for patients is a critical, but difficult undertaking. Accordingly, we continually evaluate our development programs as data emerge to support prudent decisions that provide value both to the patients we serve and our shareholders," said James Rusnak, MD, PhD, Chief Development Officer, Cardiovascular and Metabolic Diseases, Pfizer Global Product Development. "We are disappointed by this outcome, but remain committed to investing in innovation, concentrating our pipeline on areas where we can bring transformational therapies to address unmet needs, including in patients with cardiovascular and metabolic diseases. We thank the investigators, their patients, and support staff who have participated in this important research program." Pfizer is working to ensure that all regulatory authorities are informed, and that all trial investigators are informed and instructed on next steps. If patients have questions, they should speak with their study physician for more information.