OBJECTIVES: Specialty therapies are increasingly being self-administered, requiring patients and caregivers to have a thorough understanding of reconstituting and injecting these medications.  This study measures treatment adherence evaluated by the use of a patient activation measure (PAM) and administration comfortability of C1 esterase inhibitor therapy for hereditary angioedema patients. METHODS: Hub-enrolled patients diagnosed and prescribed C1 esterase inhibitor therapy were segmented utilizing the PAM and then trained on reconstituting and administering the therapy by field education nurses. Patients demonstrating an adequate ability to administer therapy were deemed “comfortable.” Those deemed “uncomfortable” had family members trained to administer therapy, or treatment was administered on demand by healthcare professionals. Based on baseline PAM levels, patients were provided tailored call cadence schedules to uncover limiting self-administration barriers for level 1 and 2 patients and continuing education for level 3 and 4 patients. All patients were followed prospectively to assess treatment utilization and adherence (medication possession ratio). RESULTS: