Characterization of US patients with alpha-1 antitrypsin deficiency treated with an alpha-1 proteinase inhibitor

Currently, specific therapy for alpha-1 antitrypsin deficiency (AATD) consists solely of augmentation therapy with alpha-1 proteinase inhibitors, including Glassia (Alpha₁-PI). The real-world experience and impact of Alpha₁-PI have not been well characterized. The aim of this retrospective cohort study was to describe the characteristics and healthcare resource utilization (HCRU) of patients with AATD receiving Alpha₁-PI.

De-identified records from adults with diagnosed AATD (aged ≥18 years) who had ≥2 in/outpatient claims and ≥12 months of continuous enrollment before and after the index date were evaluated as sub-cohorts, with analysis focusing primarily on patients receiving Alpha₁-PI. Outcomes included baseline demographics, clinical characteristics, AAT testing rates, treatment patterns, and HCRU, with descriptive statistics calculated for continuous variables and categorical measures.

249 patients were identified as Alpha₁-PI users, of which 159 (63.8%) were new users. At baseline, the most common comorbidities were any chronic pulmonary disease (95.2%), hypertension (59.4%), and emphysema (46.2%). AAT testing rates during the study period were 49.4% and 56.6% among anytime and new Alpha₁-PI users, respectively. During 12 months of follow-up, new Alpha₁-PI users achieved a mean of 22.3 (standard deviation, 16.2) prescription claims. In total, 103 (64.8%) patients adhered to treatment (proportion of days covered ≥80%). Seventy-four new users (46.5%) persisted in using Alpha₁-PI, whilst 45 (28.3%) discontinued and started another augmentation therapy. Most patients required outpatient visits (99.2%).

Claims-based adherence may be misclassified because an infusion claim does not confirm administration, and some Alpha₁-PI claims may bundle multiple infusions. As a result, proportion of days covered and observed treatment patterns may be overestimated and may reflect reimbursement patterns rather than actual use.

Patients with AATD had a high burden of comorbidities, treatment discontinuations and switching, and HCRU, demonstrating an unmet need when utilizing Alpha₁-PI for augmentation therapy.