Subcutaneous immunoglobulin replacement therapy in patients with immunodeficiencies - impact of drug packaging and administration method on patient reported outcomes

Abstract

Background: Here, the perspective of patients with primary and secondary immunodeficiency receiving subcutaneous immunoglobulin (SCIg) via introductory smaller size pre-filled syringes (PFS) or vials were compared.

Methods: An online survey was conducted in Canada by the Association des Patients Immunodéficients du Québec (APIQ) (10/2020-03/2021). Survey questions included: reasons for choosing SCIg packaging and administration methods, training experiences, infusion characteristics, and switching methods. The survey captured structured patient-reported outcomes: treatment satisfaction and its sub-domains, symptom state, general health perception, and physical and mental function. Respondents using PFS were compared with vial users, overall and stratified by their administration method (pump or manual push).

Results: Of the 132 total respondents, 66 respondents used vials, with 38 using a pump and 28 using manual push. PFS (5 and 10 mL sizes) were being used by 120 respondents, with 38 using a pump and 82 using manual push. PFS users were associated with a 17% lower median (interquartile range) SCIg dose (10 [8, 12] vs. 12 [9, 16] g/week, respectively), a significantly shorter infusion preparation time (15 [10, 20] vs. 15 [10, 30] mins, respectively), and a trend for shorter length of infusion (60 [35, 90] vs. 70 [48, 90] mins, respectively) compared with those on vials. Patient-reported treatment satisfaction scores were overall similar between vial and PFS users (including on the domains of effectiveness and convenience), except for a higher score for vials over PFS on the domain of global satisfaction (p=0.02).

Conclusions: Consistent with prescribing that reflects a recognition of less wastage, PFS users were associated with a significantly lower SCIg dose compared with vial users. PFS users were also associated with shorter pre-infusion times, reflecting simpler administration mechanics compared with vial users. Higher global satisfaction with treatment among vial users compared with PFS users was consistent with users being limited to smaller PFS size options in Canada during the study period. Patient experience on PFS is expected to improve with the introduction of larger PFS sizes. Overall, treatment satisfaction for SCIg remains consistently high with the introduction of PFS packaging compared with vials.

Keywords: Immunodeficiency; Manual push; Packaging method; Patient reported outcomes; Pre-filled syringes (PFS); Pump; Subcutaneous immunoglobulin (SCIg); Treatment satisfaction questionnaire for medication (TSQM); Vials.

Fig. 1

Design of PFS. Figure was repurposed from Ayman R. Kafal, Donald C. Vinh & Mélanie J. Langelier [31] Prefilled syringes for immunoglobulin G (IgG) replacement therapy: clinical experience from other disease settings, Expert Opinion on Drug Delivery, 15:12, 1199-1209, https://doi.org/10.1080/17425247.2018.1546692 and is covered by the Creative Commons Attribution-NonCommercial-NoDerivatives License. PFS, pre-filled syringes

Fig. 2

Criteria used to include respondents in the study. IgRT, immunoglobulin replacement therapy; PFS, pre-filled syringes; SCIg, subcutaneous immunoglobulin

Fig. 3

Clustered bar chart of respondents’ reasons for choosing a SCIg packaging method, stratified by SCIg administration method (pump and manual push). (A) All respondents, (B) pump subgroup, and (C) manual push subgroup. PFS, pre-filled syringes; SCIg, subcutaneous immunoglobulin

Fig. 4

Perceived treatment effectiveness in the vial and PFS cohorts, stratified by SCIg administration method (pump and manual push). (A) Transformed TSQM effectiveness domain scores and (B) raw scores from the corresponding TSQM domain items. *n numbers vary due to missing respondent data for various survey questions. Transformed domain scores are on a 0–100 scale from worst to best and the raw scores are on a 1 to 5 or 7 scale from extremely dissatisfied to extremely satisfied. Continuous variables were compared using an unpaired t-test and only the significant p values are included in the figure for brevity. PFS, pre-filled syringes; SCIg, subcutaneous immunoglobulin; SD, standard deviation; TSQM, treatment satisfaction questionnaire for medication

Fig. 5

Perceived treatment convenience in the vial and PFS cohorts, stratified by SCIg administration method (pump and manual push). (A) Transformed TSQM convenience domain scores and (B) raw scores from the corresponding TSQM domain items. *n numbers vary due to missing respondent data for various survey questions. Transformed domain scores are on a 0–100 scale from worst to best and the raw scores are on a 1 to 5 or 7 scale from extremely dissatisfied to extremely satisfied. Continuous variables were compared using an unpaired t-test and only the significant p values are included in the figure for brevity. PFS, pre-filled syringes; SCIg, subcutaneous immunoglobulin; SD, standard deviation; TSQM, treatment satisfaction questionnaire for medication

Fig. 6

Perceived treatment global satisfaction in the vial and PFS cohorts, stratified by SCIg administration method (pump and manual push). (A) Transformed TSQM global satisfaction domain scores and (B) raw scores from the corresponding TSQM domain items. *n numbers vary due to missing respondent data for various survey questions. Transformed domain scores are on a 0–100 scale from worst to best and the raw scores are on a 1 to 5 or 7 scale from extremely dissatisfied to extremely satisfied. Continuous variables were compared using an unpaired t-test and only the significant p values are included in the figure for brevity. PFS, pre-filled syringes; SCIg, subcutaneous immunoglobulin; SD, standard deviation; TSQM, treatment satisfaction questionnaire for medication

Fig. 7

Respondent symptom state and perceived health status in the vial and PFS cohorts, stratified by SCIg administration method (pump and manual push). (A) Proportion of respondents who responded ‘affirmative’ to whether they were at an acceptable symptom state (as measured using PASS), (B) proportion of respondents who described their current health status as ‘fair’, ‘good’, ‘very good’ or ‘excellent’ (as measured using GHP), and (C) transformed scores for PROMIS GPH-2 and GMH-2. The complementary response category for PASS was ‘negative’ and for GHP were ‘poor’ or ‘very poor’. GHP, general health perception; GMH-2, global mental health 2; GPH-2, global physical health 2; IVIg, intravenous immunoglobulin; PASS, patient acceptable symptom state; PFS, pre-filled syringes; PROMIS, patient-reported outcomes measurement information system; SCIg, subcutaneous immunoglobulin