Momenta Pharmaceuticals, Inc. announced the launch of an adaptive Phase 2/3 clinical study for its FcRn inhibitor nipocalimab (M281) in warm Autoimmune Hemolytic Anemia (wAIHA). This follows the acceptance of its Investigational New Drug (IND) application by the U.S. Food and Drug Administration. The FDA has also granted Fast Track Designation for nipocalimab in wAIHA. wAIHA is a rare autoimmune disease with high unmet medical need and no labelled treatments. By targeting FcRn as a mechanism to reduce circulating levels of pathogenic IgG antibodies, nipocalimab could offer significant potential benefit for patients with this devastating severe immune mediated disease. study initiation is an important milestone for Momenta, marking the start of its third clinical study of nipocalimab in auto and alloimmune diseases. To date, nipocalimab has exhibited a best-in-class profile and continue to believe in its broad market potential across a range of immune-mediated diseases. Moreover, if successful, this adaptive Phase 2/3 study could serve as a pivotal study which could enable nipocalimab to be the first treatment option for wAIHA patients. This randomized, double blind, placebo-controlled, multi-center, adaptive Phase 2/3 clinical trial will investigate the efficacy, safety and tolerability of nipocalimab (M281) in patients with wAIHA. Often used in rare diseases, adaptive study designs allow for modification of the study design and hypotheses based on interim analyses of the data. This strategy allows for greater flexibility and efficiencies in study design, which can benefit both sponsors and patients in diseases with large unmet need, as the amount of useful data collected is maximized. wAIHA is a rare autoimmune hemolytic anemia characterized by the destruction of red blood cells due to the presence of pathogenic IgG autoantibodies. Destruction of red blood cells results in severe anemia, leading to weakness and fatigue. As the disease progresses, and without safe and effective treatment, serious complications can develop. Up to 8% of wAIHA patients may die prematurely, with those experiencing active and uncontrolled hemolysis most at risk. Rates as high as 30% have been observed for wAIHA patients with severe disease admitted to an ICU. All suffer from serious complications from the disease and its associated treatments. Using proprietary antibody engineering technology, Momenta has developed nipocalimab (M281), a fully human, anti-FcRn, aglycosylated IgG1 monoclonal antibody. In patients with wAIHA, nipocalimab is expected to rapidly ameliorate the physical and laboratory manifestations of the disease by blocking FcRn-mediated recycling of IgG and reducing circulating levels of antibodies, including the pathogenic autoantibodies that cause wAIHA. Momenta previously reported positive data showing safety, tolerability and proof of mechanism for nipocalimab in a Phase 1 single ascending dose (SAD) and multiple ascending dose (MAD) study of normal human volunteers. Over the 98-day MAD study, nipocalimab exhibited no serious adverse events, was well tolerated, and decreased circulating IgG levels up to 89% with a mean reduction of 84%. Nipocalimab is also being evaluated in two ongoing Phase 2 trials: the Vivacity-MG clinical trial, a randomized, double-blinded, placebo-controlled multi-dose trial in 60 generalized myasthenia gravis patients where top line data is anticipated in the second or third quarter of 2020; and the Unity trial, an open label Phase 2 clinical trial of nipocalimab in 15 pregnant women at high risk for early onset severe hemolytic disease of the fetus and newborn (HDFN), with top line data anticipated in 2021.