Methods: Pooled analyses were based on five Phase III studies of Hizentra®(two pivotal; three extension/follow-up) conducted in the EU, Japan, and the US. Life Quality Index (LQI) and Short Form 36, version 2 (SF36v2) questionnaires were used to assess TS and HRQoL, respectively, at baseline and every 6–24 weeks thereafter (or at baseline and 60 weeks for TS in the US extension study).
Results: EU and Japanese pivotal studies demonstrated significant improvements in mean LQI score by sum of all questions (from 4.87 at baseline to 5.70 at Week 40; p <0.001), largely driven by patients switching from previous IVIG therapy. Extension studies, where patients continued steady-state Hizentra® dosing for up to 3 years, showed no relevant mean LQI score changes from extension baseline to study end by sum of all questions (5.75 vs. 5.87; p=0.26) or by individual questions. Median SF36v2 scores did not change upon switching to Hizentra®in the EU pivotal study, possibly reflecting low sensitivity of the instrument. Long-term extension HRQoL studies provided limited conclusions due to the small number of patients.
Conclusions: Patient TS in Caucasian and Japanese patients with PID significantly improves upon switching from previous IVIG treatment to Hizentra® and is maintained for up to 3 years under clinical study conditions.