Improvement in Quality of Life Measurements in Newly Diagnosed Patients with Primary Immunodeficiency Receiving Directly Initiated Subcutaneous Replacement Therapy with Vivaglobin

RATIONALE: We report for the first time direct initiation of subcutaneous administration of human IgG (SCIG) in previously untreated patients with primary immunodeficiencies (PID), in contrast to typical clinical practice of initiation with an intravenous IgG loading and subsequent switching to SCIG when desired. METHODS: A phase III prospective, open-label, multicenter, single-arm study enrolled 18 patients (1-70 years) with newly diagnosed PID. Patients received a nurse-supervised loading dose of SCIG 100 mg/kg for 5 consecutive days followed by maintenance therapy with a weekly dose of 100 mg/kg. Duration of treatment was 24 weeks. Health-related quality of life (HRQL) measurements included adapted Short Form 36 survey (SF-36) or adapted Child Health Questionnaire Parent Form 50 (CHQ-PF50) for patients aged ≤13 years. RESULTS: Patients’ satisfaction with therapy was reflected in the low discontinuation rate compared to other SCIG studies. A substantial improvement from screening to completion visit was observed in mean SF-36 domain scores for general health (13 points), vitality (12.7 points) and social functioning (15 points). A mean improvement of more than 20 points in CHQ-PF50 scores from baseline was reported for global health (26.9 points), physical functioning (20.1 points), change in health (40.6 points) and role/social limitations - emotional/behavioral (20.8 points). These scales had relatively low scores at baseline, suggesting a substantial potential for HRQL improvement with SCIG therapy. CONCLUSIONS: Therapy can be successfully initiated with a SCIG loading phase in newly diagnosed PID patients, challenging the widespread recommendation for an initial intravenous IgG phase, and resulting in substantial improvement in HRQL indicators.