Lupus nephritis is an immune complex-mediated inflammatory destruction of the kidney’s filtration apparatus, and is the most common life-threatening manifestation of SLE. SLE is an autoimmune disorder affecting 1.5 million people in the United States. Approximately 200,000 SLE patients suffer from severe lupus nephritis. These patients are primarily young women, although SLE may affect any age group. Improved treatment of SLE is widely considered to be a major unmet need. Currently available treatments for lupus nephritis are often ineffective, and their use may be limited by toxicity.

Drug development in SLE is confounded by the complex and variable course of the disease. This makes clinical trial design challenging, particularly for treatments intended for chronic administration. In contrast, we expect the initial therapeutic application for either Az 121 or Az 175 will require one to, at most, several doses for induction of remission of severe lupus nephritis flares. Targeting this clinically meaningful outcome will require a relatively simple clinical trial design of short duration with well- defined endpoints.