This is a 2-part randomized, double-blind, placebo-controlled study followed by an OLE of APT-1011 in adults with EoE.~Part A will evaluate the efficacy and safety of APT-1011 3 mg administered HS for the induction of response to treatment (histologic and symptomatic) over 12 weeks.~At Week 14, subjects will move into Part B. Subjects with histological response to APT-1011, defined as ≤6 peak eos/HPF, will be re-randomized to continue APT-1011 or receive placebo (active treatment withdrawal). APT-1011 histological non-responders will continue APT-1011, and placebo histological non-responders will receive APT-1011 3 mg HS. Placebo histological responders will continue placebo. The double-blind will be sustained throughout Part B. Histological responder status will be determined at the time of esophagogastroduodenoscopy (EGD) in Part B (at or prior to Week 52, depending on unscheduled EGDs performed when the Investigator deems the subject's symptoms necessitate EGD) and is defined as ≤6 peak eos/HPF.~At Week 52, subjects may enter Part C, an open-label single-arm extension phase, and continue study drug uninterrupted. Part C will terminate upon regulatory approval of APT-1011 or Sponsor termination of the study.
This is a 2-part randomized, double-blind, placebo-controlled study followed by an open-label extension (OLE) of APT-1011 in adults with EoE.~Part A will evaluate the efficacy and safety of APT-1011 3 mg administered hora somni (HS; at bedtime) for the induction of response to treatment (histologic and symptomatic) over 12 weeks.~Part B will evaluate histological relapse-free status in patients re-randomized to continue APT-1011 or placebo (active treatment withdrawal) until Week 52.~Part C, the OLE, will continue until regulatory approval of APT-1011 or Sponsor termination of the study.