The POLARIS study is designed to evaluate how well efgartigimod PH20 SC may work (called "efficacy") and how safe it is for people diagnosed with Autoimmune Encephalitis (AIE). The study consists of 4 parts: in part A participants will receive efgartigimod SC; in part B, participants will be randomized to receive either efgartigimod SC or placebo; in part C, participants who completed part B will receive efgartigimod SC; in part D, participants who completed part C will be observed after their last dose of efgartigimod SC. If AIE symptoms return, efgartigimod SC treatment may be restarted during this time.
The maximum overall study duration for participants is up to 3 years. More information can be found in clinicaltrials.argenx.com/polaris
Is at least 12 years of age.
Meeting at least the criteria for possible AIE according to the Graus criteria.
Known anti-myelin oligodendrocyte glycoprotein (anti-MOG) antibody positivity.
Any medical condition that would interfere with an accurate assessment of clinical symptoms of AIE.
Recent major surgery (within 3 months of screening) or intention to have major surgery during the study, except for surgeries for AIE-related teratomas and thymomas.
History (within 12 months before screening) of current alcohol, drug (including recreational or prescribed cannabinoids), or medication abuse.