Clinical Profile, Dosing, and Quality-of-Life Outcomes in Primary Immune Deficiency Patients Treated at Home with Immunoglobulin G: Data from the IDEaL Patient Registry.

BACKGROUND

Patients with primary immune deficiency (PID) often require immunoglobulin G (IgG, commonly referred to as Ig) replacement therapy to prevent infections and associated comorbidities. Ig therapy can be given either through intravenous or subcutaneous routes, and both can be done in the home setting. There is limited information available on the real-world diagnosis, management, and outcomes of this patient population, given the variable disease presentation and treatment options. The Immunoglobulin Diagnosis, Evaluation, and key Learnings (IDEaL) Patient Registry is designed to capture nursing, pharmacy, and patient-reported data for patients receiving Ig at home.

OBJECTIVES

To (a) present a real-world population of patients with PID who have received Ig at home and (b) examine how differences in administration, dosing, and insurance affect health and quality-of-life outcomes in these patients.

METHODS

As of July 2015, 383 patients receiving Ig therapy from Coram/CVS specialty infusion services, across multiple disease states, signed consent forms and enrolled in the IDEaL Patient Registry. Patients' referral paperwork, including lab values, and standard of care nursing and pharmacy follow-up forms were collected. Patients were mailed quality-of-life surveys at the time of enrollment and every 6 months after their enrollment.

RESULTS

The most common diagnosis (78%) in these PID patients was common variable immunodeficiency (CVID). For Ig-naive adult patients, the average age at the start of treatment was 59 years. For pediatric patients, average age at start of treatment was 9 years. A majority of these PID patients (80%) received subcutaneous Ig (SCIg) at home, and 20% received intravenous Ig (IVIg). The average SCIg dose was 10 grams per week, or 130 mg per kg, and the average IVIg dose was 36 grams every 4 weeks, or 472 mg per kg. In the IVIg patient population, 34% had a dose or frequency change while on treatment, while 30% of the SCIg patients had a dose or frequency change. Patient-reported health and quality-of-life scores were generally positive. Route of administration did not affect patient perception of cost (P = 0.171), but whether the patient had private or government-backed health care did affect perception of cost (P = 0.036).

CONCLUSIONS

For a disease state with an extremely variable presentation, data from the IDEaL Patient Registry provides further insights into the real-world clinical and diagnostic characteristics of this population, as well as dosing and treatment outcomes of home administration of Ig therapy. The majority of patients received SCIg infusions. SCIg dosing was on the lower end of the recommended mg per kg dose range, while IVIg patients were more in the middle of the recommended dose range. Patient outcomes on treatment were correlated with baseline status, suggesting that earlier detection and treatment of primary immune deficiencies may be critical in achieving beneficial outcomes on Ig therapy.

DISCLOSURES

No outside funding supported this study. Seidu was compensated by Coram Clinical Trials for acting as primary investigator and reviewing data. Study concept and design were contributed by all the authors. Kearns, Kristofek, and Kiles collected the data, and data interpretation was performed by Kearns, Seidu, and Kristofek, along with Bolgar. The manuscript was written and revised primarily by Kearns, along with Kristofek, Bolgar, and Seidu.