Developing novel drugs for systemic lupus erythematosus. Lessons learned from the belimumab trials

Abstract

Systemic lupus erythematosus is the prototypic autoimmune disease with a broad range of clinical manifestations and a complex pathogenesis. B-cells hold a central role in its pathogenesis, not only as autoantibody producing cells, but also by producing other inflammatory mediators and by presenting autoantigens to autoreactive T cells. BlyS, a soluble ligand of the TNF cytokine family, is a key factor affecting B-cell homeostasis and survival and its blockade ameliorated the disease in animal models and preclinical studies of SLE. Following an unsuccessful phase II trial of belimumab, a monoclonal antibody targeting BlyS, two large phase III studies in patients with mild-to-moderate disease, BLISS-52 and BLISS-76, met their primary endpoints showing better efficacy of the drug over standard of care alone. To this end, development of a novel more sensitive responder index and improvements in study designs were crucial. As a result, belimumab became the first drug to get approval for the treatment of SLE after more than 50 years. In this paper we discuss the rationale, development, indications, lessons learned, pitfalls and challenges for this novel therapy and point-out to additional issues that need to be addressed in the future.http://dx.doi.org/10.7175/rhc.v3i3.206