Immune globulin subcutaneous, human - klhw 20% for primary humoral immunodeficiency: an open-label, Phase III study

Suboptimal Response to Biologics in Severe Asthma-A Marker of Humoral Immunodeficiencies

BACKGROUND

Asthmatic patients with antibody deficiencies (AD) have more severe disease and higher risk of exacerbations. No data exist about the efficacy of biologics in severe asthma (SA) patients with AD.

OBJECTIVE

To evaluate the efficacy of biologics in SA patients with and without AD.

METHODS

A case-control real-life study was conducted including 68 patients divided into 2 groups: group 1 with SA-AD and group 2 with SA.

RESULTS

Treatment with biologics for 6 months was effective for decreasing the number of exacerbations, hospitalizations, and emergency department (ED) visits and improving the Asthma Control Questionnaire (ACQ) score; biologics also proved a systemic corticosteroid-sparing effect. Despite benefits, the number of exacerbations, hospitalizations, and ED visits, the mean ACQ score, and the cumulative dose of systemic corticosteroids remain higher in group 1 than in group 2, with lower lung function parameters. The rates of responses in group 1 were inferior to those in group 2, with a decrease by ≥50% of exacerbation rate in 76% versus 97% of patients (P = .006), no hospitalization in 44% versus 91% of patients (P < .001), no ED visit in 56% versus 82% of patients (P = .018), a significant improvement of the ACQ score by ≥0.5 in 68% versus 100% of patients (P < .001), and an increase of forced expiratory volume in the first second by >10% in 32% versus 65% of patients (P = .007).

CONCLUSIONS

Despite evident benefits, SA patients with AD have suboptimal responses to biologics compared with those immunocompetent. A multidisciplinary approach is necessary to optimize the management of these patients in practice.

A Phase 1 Open-Label Study to Assess the Tolerability, Safety, and Immunogenicity of Hyaluronidase-Facilitated Subcutaneous Immunoglobulin 20% in Healthy Adults

PURPOSE

Hyaluronidase-facilitated subcutaneous immunoglobulin (fSCIG) 20% will allow reduced infusion volumes and frequency versus existing subcutaneous therapies such as fSCIG 10% and conventional subcutaneous immunoglobulin 20%, respectively. We assessed the tolerability, safety, and immunogenicity of warmed and unwarmed fSCIG 20%.

METHODS

This phase 1, single-dose, open-label, three-arm study enrolled healthy adults aged 19-50 years (inclusive) at a single US center (NCT05059977). Post-screening, participants received a single fSCIG 20% dose comprising recombinant human hyaluronidase and varying doses of in-line warmed or unwarmed immunoglobulin G (IgG) during a 4-day treatment period in a sentinel and sequential dosing design (treatment arm 1, warmed IgG 20% 0.4 g/kg; treatment arm 2, warmed IgG 20% 1.0 g/kg; treatment arm 3, unwarmed IgG 20% 1.0 g/kg). Participants were followed for 12 (± 1) weeks post-infusion. The primary endpoint was tolerability ("tolerable" infusions were not interrupted, stopped, or reduced in rate owing to fSCIG 20%-related treatment-emergent adverse events (TEAEs)). Secondary endpoints included occurrence of TEAEs.

RESULTS

Overall, 24 participants were included, 8 per treatment arm (mean age 39.0 years, 54.2% men). All participants tolerated the infusions. All TEAEs were mild (107 events, in all participants), and all participants experienced fSCIG 20%-related (105 events) and local (102 events) TEAEs. Infusion site erythema and infusion site swelling were most frequently reported. No serious TEAEs occurred, and no participants discontinued the study owing to TEAEs.

CONCLUSION

fSCIG 20% was well-tolerated with a favorable safety profile in healthy adults. Future studies will evaluate fSCIG 20% in primary immunodeficiency diseases. Trial registration number (ClinicalTrials.gov): NCT05059977 (registered 28 September 2021).

An updated perspective on immunoglobulin replacement in chronic lymphocytic leukaemia in the era of targeted therapies

Chronic lymphocytic leukaemia (CLL) is a malignancy of clonally expanded antigen-switched, neoplastic, mature B cells. CLL is characterised by a variable degree of immunosuppression and secondary hypogammaglobulinemia. B-cell depleting therapies have historically been deployed with a proportion of patients becoming resistant to multiple lines of treatment with an associated worsening of immunosuppression and heightened infection risk. Advances in molecular diagnostics and the development of new therapies targeting Bruton's tyrosine kinase and B-cell lymphoma-2 have resulted in novel insights into the cellular mechanisms associated with an increased infection risk and T-cell escape from the complex tumour environment found in CLL. Generally, immunoglobulin replacement therapy with polyvalent human immunoglobulin G (IgG) is indicated in patients with recurrent severe bacterial infections and low IgG levels, but there is no consensus on the threshold IgG level for initiation of such therapy. A proportion of CLL patients have residual IgG production, with preserved quality of the immunoglobulin molecules, and therefore a definition of 'IgG quality' may allow for lower dosing or less frequent treatment with immunoglobulin therapy in such patients. Immunoglobulin therapy can restore innate immunity and in conjunction with CLL targeted therapies may allow T-cell antigen priming, restore T-cell function thereby providing an escape from tumour-associated autoimmunity and the development of an immune-mediated anti-tumour effect. This review aims to discuss the mechanisms by which CLL-targeted therapy may exert a synergistic therapeutic effect with immunoglobulin replacement therapy both in terms of reducing tumour bulk and restoration of immune function.

Pharmacokinetic modeling and simulation of subcutaneous and intravenous IgG dosing in patients with primary immunodeficiency diseases

A population pharmacokinetic (PK) model for comparing the PK of subcutaneously administered immunoglobulin G (IgG) replacement therapy (SCIG) with Gamunex-C 10% or SCIG 20% formulations in patients with primary immunodeficiency diseases was developed using data from 3 clinical trials (N = 95, 69.5% adults, 30.5% <18 years) of intravenous IG (IVIG) 10% and SCIG 10% or SCIG 20%. Serum IgG exposure following switches from IVIG 10% every 3 or 4 weeks to biweekly SCIG 20% (dose adjustment factor 1.0 or 1.37) and from weekly SCIG 20% to biweekly SCIG 20% or SCIG 20% 2-7 times/week was simulated. The PK of IVIG 10% and SCIG 20% were adequately described by a 2-compartment model with first-order absorption rate constant of exogenous IgG from an SC depot compartment into the central compartment and first-order elimination from the central compartment. Switching from IVIG 10% every 4 weeks to biweekly SCIG 20% produced similar serum IgG exposure, with lower peak and higher trough serum IgG concentrations. Switching from IVIG 10% every 3 or 4 weeks to weekly and biweekly SCIG 20% yielded comparable IgG exposure and clinically effective trough IgG concentrations.

A Multi‑Center, Open‑Label, Single‑Arm Trial to Evaluate the Efficacy, Pharmacokinetics, and Safety and Tolerability of IGSC 20% in Subjects with Primary Immunodeficiency

Purpose

The purpose of this phase 3 study was to evaluate the efficacy, pharmacokinetics (PK), and safety of Immune Globulin Subcutaneous (Human), 20% Caprylate/Chromatography Purified (IGSC 20%) in patients with primary immunodeficiency (PI).

Methods

Immunoglobulin treatment-experienced subjects with PI received 52 weeks of IGSC 20% given weekly at the same dose as the subject’s previous IgG regimen (DAF 1:1); the minimum dose was 100 mg/kg/week. The primary endpoint was serious bacterial infections (SBIs [null vs alternative hypothesis: SBI rate per person per year ≥ 1 vs < 1]). IgG subclasses and specific pathogen antibody levels were also measured.

Results

Sixty-one subjects (19 children [≤ 12 years], 10 adolescents [> 12–16 years], and 32 adults) were enrolled. The rate of SBIs per person per year was 0.017. The 1-sided 99% upper confidence limit was 0.036 (< 1), and the null hypothesis was rejected. The rate of hospitalization due to infection per person per year was 0.017 (2-sided 95% confidence interval: 0.008–0.033) overall. The mean trough total IgG concentrations were comparable to the previous IgG replacement regimen. The average of the individual mean trough ratios (IGSC 20%:previous regimen) was 1.078 (range: 0.83–1.54). The average steady-state mean trough IgG concentrations were 947.64 and 891.37 mg/dL, respectively. Seven subjects had serious treatment-emergent adverse events (TEAEs); none was drug-related. The rate of all TEAEs, including local infusion site reactions, during 3045 IGSC 20% infusions was 0.135. Most TEAEs were mild or moderate.

Conclusions

IGSC 20% demonstrated efficacy and good safety and tolerability in subjects with PI.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10875-021-01181-6.