Subcutaneous immunoglobulin: facilitated infusion and advances in administration

Safety profile of efgartigimod from global clinical trials across multiple immunoglobulin G-mediated autoimmune diseases

BACKGROUND

Efgartigimod is approved in multiple regions for the treatment of gMG, ITP, and CIDP, and is being evaluated in multiple IgG-mediated autoimmune diseases. Here, we report the long-term safety profiles of efgartigimod IV and PH20 SC across different dosing regimens and diseases where efgartigimod has received regulatory approval.

RESEARCH DESIGN AND METHODS

Efgartigimod safety was assessed across dosing regimens and administration routes in Phase 2, placebo-controlled Phase 3, and OLE studies in participants with gMG, ITP, and CIDP. Analyses were performed on all participants who received ≥ 1 dose or partial dose of efgartigimod or placebo. Data from efgartigimod-treated participants were pooled per disease. Event rates were calculated as events per PYFU.

RESULTS

Pooled data included 715 participants representing > 850 PYFU. In efgartigimod-treated participants, most TEAEs were mild-to-moderate in severity, with consistently low event rates for TEAE-related treatment discontinuation (range: 0.05-0.47). Severe and serious infection rates were comparable between placebo- and efgartigimod-treated participants. Rates of TEAEs, severe and serious infections, and treatment discontinuation did not increase with prolonged efgartigimod exposure. Efgartigimod did not reduce albumin or increase LDL cholesterol levels.

CONCLUSIONS

Across clinical trials in IgG-mediated autoimmune diseases, efgartigimod was well tolerated with similar safety profiles regardless of dosing regimen.

Long-term safety and tolerability of hyaluronidase-facilitated subcutaneous immunoglobulin 10% as maintenance therapy for chronic inflammatory demyelinating polyradiculoneuropathy: Results from the ADVANCE-CIDP 3 trial

BACKGROUND AND AIMS

Hyaluronidase-facilitated subcutaneous immunoglobulin (fSCIG) consists of subcutaneous human immunoglobulin G (IgG) 10% with recombinant human hyaluronidase (rHuPH20) and can be administered at the same dose and interval as intravenous IgG (IVIG). fSCIG recently received US approval as maintenance therapy for adults with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) and European approval for adults and children with CIDP after stabilization with IVIG.

METHODS

ADVANCE-CIDP 3 (NCT02955355) was an open-label long-term extension of the Phase 3 double-blind randomized placebo-controlled ADVANCE-CIDP 1 study (NCT02549170) that examined fSCIG safety and efficacy as maintenance CIDP therapy. Primary outcomes were safety, tolerability, and immunogenicity. Efficacy was an exploratory outcome.

RESULTS

The study provided 220 patient-years of follow-up data from 85 patients. Median (range) exposure was 33 (0-77) months. Patients received fSCIG every 4 weeks (88.2%) or every 3 weeks (11.8%). Median (range) 4-weekly IgG dose equivalent was 64.0 (28.0-200.0) g. Mean (standard deviation) infusion duration was 135.5 (62.8) minutes. Most adverse events (AEs) were mild or moderate and self-limiting. Of the 1406 AEs, only 48 were severe and 30 were serious. fSCIG-related AEs (n = 798) included infusion site reactions such as pain, redness, and pruritus. Three infusions (0.1%) were reduced in rate, interrupted, or stopped due to intolerability. Relapse occurred in 10 of 77 patients (13.0%); annual relapse rate was 4.5%. An anti-rHuPH20 antibody titer ≥1:160 was detected in 14 of 84 patients (16.7%); patients who tested positive (≥1:160) had similar relapse rates versus those who tested negative (16.7% vs. 12.3%, respectively).

INTERPRETATION

ADVANCE-CIDP 3 demonstrated favorable fSCIG long-term safety and tolerability consistent with its established safety profile, and a low relapse rate, supporting use as maintenance CIDP treatment.

Hyaluronidase-facilitated subcutaneous immunoglobulin 10% as maintenance therapy for chronic inflammatory demyelinating polyradiculoneuropathy: The ADVANCE-CIDP 1 randomized controlled trial

BACKGROUND AND AIMS

ADVANCE-CIDP 1 evaluated facilitated subcutaneous immunoglobulin (fSCIG; human immunoglobulin G 10% with recombinant human hyaluronidase) efficacy and safety in preventing chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) relapse.

METHODS

ADVANCE-CIDP 1 was a phase 3, double-blind, placebo-controlled trial conducted at 54 sites in 21 countries. Eligible adults had definite or probable CIDP and adjusted Inflammatory Neuropathy Cause and Treatment (INCAT) disability scores of 0-7 (inclusive), and received stable intravenous immunoglobulin (IVIG) for ≥12 weeks before screening. After stopping IVIG, patients were randomized 1:1 to fSCIG 10% or placebo for 6 months or until relapse/discontinuation. fSCIG 10% was administered at the same dose (or matching placebo volume) and interval as pre-randomization IVIG. The primary outcome was patient proportion experiencing CIDP relapse (≥1-point increase in adjusted INCAT score from pre-subcutaneous treatment baseline) in the modified intention-to-treat population. Secondary outcomes included time to relapse and safety endpoints.

RESULTS

Overall, 132 patients (mean age 54.4 years, 56.1% male) received fSCIG 10% (n = 62) or placebo (n = 70). CIDP relapse was reduced with fSCIG 10% versus placebo (n = 6 [9.7%; 95% confidence interval 4.5%, 19.6%] vs n = 22 [31.4%; 21.8%, 43.0%], respectively; absolute difference: -21.8% [-34.5%, -7.9%], p = .0045). Relapse probability was higher with placebo versus fSCIG 10% over time (p = .002). Adverse events (AEs) were more frequent with fSCIG 10% (79.0% of patients) than placebo (57.1%), but severe (1.6% vs 8.6%) and serious AEs (3.2% vs 7.1%) were less common.

INTERPRETATION

fSCIG 10% more effectively prevented CIDP relapse than placebo, supporting its potential use as maintenance CIDP treatment.

Home Infusion Therapy: Utilization Under the Medicare Part B Temporary Transitional Payment

The Bipartisan Budget Act (BBA) of 20181 created a temporary transitional payment (TTP) through Medicare Part B, which establishes fee-for-service (FFS) payment for eligible home infusion suppliers when they furnish home infusion therapy (HIT) service visits by skilled professionals in a beneficiary’s home on the day of HIT drug administration. Payment varies by 3 condition-specific payment categories. The Centers for Medicare & Medicaid Services (CMS) implemented the TTP on January 1, 2019. The TTP ended when the permanent HIT benefit began on January 1, 2021. To better understand how beneficiaries utilized this benefit during the TTP period, we examine trends in HIT services utilization between January 2019 and December 2020. Despite being new, the HIT benefit showed only a slight ramp-up phase, with a stable level of visits evolving over the remainder of 2019 and early 2020. Utilization decreased during the COVID-19 public health emergency, especially for infusion drugs related to heart failure and cancer. Additionally, relative to the geographic distribution of the Medicare FFS population, HIT service visit users are concentrated in the mid-Atlantic states. HIT service visit users are more likely to be young, white or black, and urban dwelling, compared to the general Medicare FFS beneficiaries.

ENHANZE® drug delivery technology: a novel approach to subcutaneous administration using recombinant human hyaluronidase PH20

ENHANZE^® drug delivery technology is based on the proprietary recombinant human hyaluronidase PH20 enzyme (rHuPH20; Halozyme Therapeutics, Inc.) that facilitates the subcutaneous (SC) delivery of co‐administered therapeutics. rHuPH20 works by degrading the glycosaminoglycan hyaluronan (HA), which plays a role in resistance to bulk fluid flow in the SC space, limiting large volume SC drug delivery, dispersion, and absorption. Co-administration of rHuPH20 with partner therapies can overcome administration time and volume barriers associated with existing SC therapeutic formulations, and has been shown to reduce the burden on patients and healthcare providers compared with intravenous formulations. rHuPH20 (as HYLENEX^® recombinant) is currently FDA-approved for subcutaneous fluid administration for achieving hydration, to increase the dispersion and absorption of other injected drugs, and in subcutaneous urography for improving resorption of radiopaque agents. rHuPH20 is also co-formulated with two anticancer therapies, trastuzumab (i.e. Herceptin^® SC) and rituximab (i.e. RITUXAN HYCELA^®/RITUXAN^® SC/MabThera^® SC) and dosed sequentially with human immunoglobin to treat primary immunodeficiency (i.e. HyQvia^®/HYQVIA^®). This article reviews pharmaceutical properties of rHuPH20, its current applications with approved therapeutics, and the potential for future developments.

Direct and Indirect Costs of Immunoglobulin Replacement Therapy in Patients with Common Variable Immunodeficiency (CVID) and X-Linked Agammaglobulinemia (XLA) in Italy

BACKGROUND

In Italy, there is scarce evidence on the epidemiological and economic burden induced by primary antibody deficiencies.

OBJECTIVE

The aim of this study was to elaborate the available epidemiological and cost data in order to estimate the annual expenditure induced by the management of patients affected by the common variable immunodeficiency (CVID) and X-linked agammaglobulinemia (XLA) requiring immunoglobulin (Ig) replacement therapy.

METHODS

A probabilistic cost-of-illness model was developed to estimate the number of patients with CVID and XLA, and the economic burden associated with their therapy in terms of direct or indirect costs. A systematic literature review was carried out to reveal both epidemiological and economic data. Furthermore, a probabilistic sensitivity analysis with 5000 Monte Carlo simulations was performed.

RESULTS

The epidemiological model allowed us to estimate the number of prevalent patients affected by XLA and CVID in Italy in 2017, corresponding to 1885 (95% confidence interval [CI] 944-3145) and 133 (95% CI 115-152) patients, respectively. The estimated total expenditure for the treatment and management of patients with CVID and XLA requiring Ig replacement therapy amounts to €42.68 million (95% CI €14.38-€86.1 million).

CONCLUSIONS

This information provides a comprehensive perspective of the economic issues, and facilitates better-informed public health decision making, in the management of CVID and XLA in Italy.

Facilitated subcutaneous immunoglobulin treatment in pemphigus vulgaris

A novel administration strategy of immunoglobulin treatment is represented by injection of recombinant human hyaluronidase (rHUPH20) with subcutaneous immunoglobulins. The use of facilitated subcutaneous immunoglobulin treatment (fSCIG) for the treatment of autoimmune conditions is yet to be investigated. We present the case of a 56-year-old female patient with pemphigus vulgaris predominantly of the oral mucous membranes, previously treated for 24 months with azathioprine and medium doses of steroids, with only partial remission. When she came to our attention, a concomitant newly diagnosed infiltrating ductal breast cancer limited the use of immunosuppressive agents. She was started with fSCIG (25 g/monthly). After 18 months of follow-up, her breast cancer has been successfully treated and a substantial decrease of the rate of bullous mucous lesions and improvement of time to lesion healing and resolution was observed. fSCIG might represent a steroid-sparing tool for the treatment of selected cases of pemphigus vulgaris.

Recombinant human hyaluronidase facilitated subcutaneous immunoglobulin treatment in pediatric patients with primary immunodeficiencies: long-term efficacy, safety and tolerability

AIM

To assess the long-term efficacy, safety and tolerability of recombinant human hyaluronidase-facilitated subcutaneous infusion of immunoglobulin (Ig) (fSCIG; HYQVIA(®); IGHy) in children aged <18 years.

PATIENTS & METHODS

Patients with primary immunodeficiency diseases were included in the studies. IGHy was administered every 3 or 4 weeks.

RESULTS

Validated acute serious bacterial infections were reported at 0.08/patient-year (four pneumonia episodes in three patients). No serious adverse drug reaction (ADR) was reported, and rates of local and systemic ADRs were low (0.09/infusion and 0.1/infusion). Infection rates were low (3.02/patient-year) with sustained Ig trough levels (median: 1009 mg/dl). Of 674 IGHy infusions, 97.2% required no change of administration due to ADR, in most (82.5%) with one infusion site. No patient developed neutralizing anti-rHuPH20 antibodies. Postpivotal study, 100% of patients aged <14 years or their caregivers and 85.7% of patients aged 14 to <18 years expressed preference for IGHy compared with Ig administered intravenously or Ig administered subcutaneously.

CONCLUSION

These studies, with the longest (maximum: 3.3 years) duration of any reported Ig replacement trials in children with primary immunodeficiency diseases, showed low infection, local and systemic reaction rates along with well-tolerated infusions given in a single site.