Subcutaneous Immunoglobulin 16.5% (Cutaquig) in Primary Immunodeficiency Disease: Safety, Efficacy, and Patient Satisfaction with Modified Dosing Regimens

Abstract

A prospective, open-label, 3-arm, multicenter, phase 3 study was conducted to evaluate the safety, efficacy, and patient satisfaction with subcutaneous immunoglobulin (SCIG) 16.5% (Cutaquig, Octapharma) administered using modified dosing regimens. The patients were segregated into 3 separate cohorts evaluating different dosing regimens using SCIG 16.5%: 1) volume assessment/site: up to a maximum 100 mL/site; 2) infusion flow rate/site: up to a maximum of 100 mL/hr/site or the maximum flow rate achievable by the tubing; 3) infusion frequency: SCIG 16.5% infused every other week at the equivalent of twice the patient’s weekly dose (body-weight dependent [mg/kg]). While the primary evaluations were related to safety and efficacy, additional evaluations related to patient satisfaction were also measured. A total of 64 patients (59 adults, 5 children/adolescents) received 1338 infusions. There were no serious bacterial infections (SBIs) during the study. The majority of treatment-emergent adverse events were considered mild (23.4%) or moderate (56.3%) in severity. The most commonly reported treatment-emergent adverse events were infusion site erythema (31.3%), infusion site pruritus, sinusitis (both 23.4%), and headache (15.6%). In cohort 1 (n = 15), the maximum tolerated volume was 100 mL/site and in cohort 2 (n = 15), the maximum tolerated infusion flow rate was 67.5 mL/hr/site, indicating that higher infusion parameters, as compared to those in the current label, are well tolerated. In cohort 3 (n = 34), biweekly trough levels demonstrated equivalency to trough levels for weekly dosing (P value = 0.0017).A standardized questionnaire was completed at the Termination Visit to record patient’s opinions regarding the new infusion regimens in the study. The majority of patients (overall and across cohorts) found the new infusion regimens to be better or somewhat better than their previous regimens (Table 1) and that switching from their previous SCIG product to SCIG 16.5% was very easy. SCIG 16.5% (Cutaquig) infusions are safe and efficacious at higher infusion parameters, and dosing every other week (biweekly) demonstrated equivalency to trough levels with weekly dosing. In addition, the majority of patients (overall and across cohorts) found the new infusion regimens to be better or somewhat better than their previous regimens.Table 1Summary of Patient Questionnaire Rating New Infusion Regimens Compared to Previous RegimensCohort 1 (n = 15)Cohort 2 (n = 15)Cohort 3 (n = 34)Better6615Somewhat Better636Neutral258Somewhat Worse002Worse112