Comparison of Weight-Based Dosing Strategies for Intravenous Immunoglobulin in Patients with Hematologic Malignancies

Cytomegalovirus Treatment in Solid Organ Transplantation: An Update on Current Approaches

OBJECTIVE

The article reviews the safety and efficacy of treatments for cytomegalovirus (CMV) in solid organ transplantation.

DATA SOURCES

A literature review was conducted in PubMed, MEDLINE, and Clinicaltrials.gov from database inception through January 2024, using terms CMV, therapy, and solid organ transplantation.

STUDY SELECTION AND DATA EXTRACTION

Clinical trials, meta-analyses, cohort studies, case reports, and guidelines were included. Letters to the editor, reviews, and commentaries were excluded.

DATA SYNTHESIS

After abstract screening and full-text review of 728 citations for eligibility, 53 were included. Valganciclovir and intravenous ganciclovir are drugs of choice for CMV management and, until recently, the availability of alternative options has been restricted due to toxicity. For instance, foscarnet and cidofovir serve as second-line agents due to potential bone marrow and renal toxicity. In patients with refractory or resistant CMV, maribavir, a novel oral agent, has proven efficacy and a lower adverse effect profile. However, in refractory or resistant CMV, foscarnet and cidofovir are preferred in invasive disease (CMV gastritis, CMV retinitis, and CMV encephalitis), high viral loads, and inability to tolerate oral preparations.

RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE

Consensus guidelines have not been revised since approval of novel antivirals in solid organ transplantation. Valganciclovir and ganciclovir remain drugs of choice for initial CMV therapy. Foscarnet, cidofovir, and maribavir are treatments for refractory or resistant-CMV.

CONCLUSIONS

Selection of CMV antiviral treatment should be determined by patient-specific factors, including severity of illness, resistant or refractory disease, dose-limiting adverse effects, and the preferred route of administration.

Population pharmacokinetics of the GIP/GLP receptor agonist tirzepatide

Tirzepatide is a first-in-class glucose-dependent insulinotropic polypeptide and glucagon-like peptide-1 receptor agonist approved as for the treatment of type 2 diabetes mellitus. A population-based pharmacokinetic (PK) model was developed from 19 pooled studies. Tirzepatide pharmacokinetics were well-described by a two-compartment model with first order absorption and elimination. The tirzepatide population PK model utilized a semimechanistic allometry model to describe the relationship between body size and tirzepatide PK. The half-life of tirzepatide was ~5 days and enabled sustained exposure with once-weekly subcutaneous dosing. The covariate analysis suggested that adjustment of the dose regimen based on demographics or subpopulations was unnecessary. The tirzepatide PK model can be used to predict tirzepatide exposure for various scenarios or populations.

Relationship between Body Composition and Serum Immunoglobulin Concentrations after Administration of Intravenous Immune Globulin-Preclinical and Clinical Evidence

The purpose of this study was to investigate the effect of obesity on immunoglobulin G (IgG) pharmacokinetics in a rat model of obesity, and to collect clinical evidence for an association between the body composition and intravenous immune globulin (IVIG) pharmacokinetic parameters in humans. In a preclinical study, pharmacokinetics of human IgG was evaluated after intravenous (IV) and subcutaneous (SC) delivery to obese and lean rats (n = 6 in each group). Serial serum samples were analyzed using an ELISA. The animal body composition was assessed using computer tomography. Patients with primary immunodeficiency currently managed with IVIG, and at a steady state, were enrolled in the clinical study (n = 8). Serum immune globulin (Ig) concentrations were measured at baseline and immediately after the administration of two consecutive treatments, with an additional measurement at two weeks after the first administration. In addition to the patient demographic and clinical characteristics, body composition was measured using bioelectrical impedance analysis. The pharmacokinetics of human IgG was significantly different between the obese and lean rats after both the IV and SC administration of 0.5 g/kg. Furthermore, a significant difference in endogenous rat IgG was observed between the two strains. In the human study, total serum IgG and subtype (IgG1, IgG2, IgG3, IgG4) half-life negatively correlated with the body mass index and fat mass. The mean change in the total serum IgG concentration was significantly correlated to body mass index and fat mass. The results of the studies corroborated one another. In the animal study, most pharmacokinetic parameters of human IgG following IV and SC administration were significantly affected by obesity and changes in the body composition. In the clinical study, the mean serum IgG change after the IVIG administration strongly correlated to the BMI and body fat mass. Future studies are needed to establish the outcomes achieved with more frequent dosing in obese individuals with primary immunodeficiency.

Immunoglobulin replacement in hematological malignancies: a focus on evidence, alternatives, dosing strategy, and cessation rule

Acquired hypogammaglobulinemia or secondary immunodeficiency (SID) occurs commonly in hematological malignancies with increasing incidence and complexity in the era of modern therapies. Despite current practice of immunoglobulin replacement (IgRT) in SID, the evidence is lacking, especially for newer treatments. We discuss the current evidence for IgRT in various disease groups including issues, such as actual or ideal body weight (IBW)-based dosing, length of treatment, antibiotic prophylaxis, and vaccination. Incidence of SID with newer treatment is lacking. While there is a trend toward decreased respiratory infections and hospitalizations with IgRT, this is not consistent across all disease course or treatment groups. Dosing and indications for cessation of IgRT are also inadequately characterized. Further randomized controlled trials (RCTs) and observational studies are required to assess the optimal indications, timing, and duration of IgRT to improve the efficacy, safety, and cost-effectiveness. Assessment of alternative and adjunctive therapies, such as vaccination and antibiotic prophylaxis could also improve the outcomes and costs.

Population Pharmacokinetic Modelling of Intravenous Immunoglobulin Treatment in Patients with Guillain-Barré Syndrome

Background and Objective

Intravenous immunoglobulin (IVIg) at a standard dosage is the treatment of choice for Guillain–Barré syndrome. The pharmacokinetics, however, is highly variable between patients, and a rapid clearance of IVIg is associated with poor recovery. We aimed to develop a model to predict the pharmacokinetics of a standard 5-day IVIg course (0.4 g/kg/day) in patients with Guillain–Barré syndrome.

Methods

Non-linear mixed-effects modelling software (NONMEM^®) was used to construct a pharmacokinetic model based on a model-building cohort of 177 patients with Guillain–Barré syndrome, with a total of 589 sequential serum samples tested for total immunoglobulin G (IgG) levels, and evaluated on an independent validation cohort that consisted of 177 patients with Guillain–Barré syndrome with 689 sequential serum samples.

Results

The final two-compartment model accurately described the daily increment in serum IgG levels during a standard IVIg course; the initial rapid fall and then a gradual decline to steady-state levels thereafter. The covariates that increased IgG clearance were a more severe disease (as indicated by the Guillain–Barré syndrome disability score) and concomitant methylprednisolone treatment. When the current dosing regimen was simulated, the percentage of patients who reached a target ∆IgG > 7.3 g/L at 2 weeks decreased from 74% in mildly affected patients to only 33% in the most severely affected and mechanically ventilated patients (Guillain–Barré syndrome disability score of 5).

Conclusions

This is the first population-pharmacokinetic model for standard IVIg treatment in Guillain–Barré syndrome. The model provides a new tool to predict the pharmacokinetics of alternative regimens of IVIg in Guillain–Barré syndrome to design future trials and personalise treatment.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40262-022-01136-z.

Prescribing Practices of Intravenous Immunoglobulin in Tertiary Care Hospitals in Malaysia: A Need for a National Guideline for Immunoglobulin Use

Rational use of drug involves the use of medicine as per clinical guidelines. Given the steady increase in the clinical utility of intravenous immunoglobulin (IVIG) either as licensed or off-label use, concerns are being raised about the possibility of supply shortages that could significantly impact patient care. Therefore, there is a need to regulate and to promote the rational use of this valuable medication. This cross-sectional chart review study attempts to evaluate the prescribing patterns of IVIG at two tertiary hospitals in Malaysia. Patients’ medical files and dispensing records were examined and compared with current guidelines. A total of 348 prescriptions for IVIG were written during the 1-year study period. The highest usage of IVIG was for neurological (47.9%), immunological (27.5%), and hematological conditions (20%). The number of prescriptions with the US Food and Drug Administration (FDA) licensed indications and off-label indications was 148 (42.5%) and 200 (57.5%), respectively. Age (OR: 1.02, 95% CI: 1.01–1.03, p = 0.003) and those admitted to the critical care units (OR: 11.11, 95% CI: 5.60–22.05, p < 0.001) were significant factors for receiving IVIG for an off-label indication. Most prescriptions (79%) had appropriate dosing. Significant factors associated with receiving inappropriate dose of IVIG include age (OR: 0.93, 95% CI: 0.89–0.97, p = 0.001) and those admitted to the critical care units (OR: 10.15, 95% CI: 3.81–27.06, p < 0.001). This study advocates the development and implementation of evidence-based clinical guidelines with prioritization protocol to ensure rational use of IVIG.

Practical guidance for the diagnosis and management of secondary hypogammaglobulinemia: A Work Group Report of the AAAAI Primary Immunodeficiency and Altered Immune Response Committees

Secondary hypogammaglobulinemia (SHG) is characterized by reduced immunoglobulin levels due to acquired causes of decreased antibody production or increased antibody loss. Clarification regarding whether the hypogammaglobulinemia is secondary or primary is important because this has implications for evaluation and management. Prior receipt of immunosuppressive medications and/or presence of conditions associated with SHG development, including protein loss syndromes, are histories that raise suspicion for SHG. In patients with these histories, a thorough investigation of potential etiologies of SHG reviewed in this report is needed to devise an effective treatment plan focused on removal of iatrogenic causes (eg, discontinuation of an offending drug) or treatment of the underlying condition (eg, management of nephrotic syndrome). When iatrogenic causes cannot be removed or underlying conditions cannot be reversed, therapeutic options are not clearly delineated but include heightened monitoring for clinical infections, supportive antimicrobials, and in some cases, immunoglobulin replacement therapy. This report serves to summarize the existing literature regarding immunosuppressive medications and populations (autoimmune, neurologic, hematologic/oncologic, pulmonary, posttransplant, protein-losing) associated with SHG and highlights key areas for future investigation.

Precision Intravenous Immunoglobulin Dosing and Clinical Outcomes: A Retrospective Chart Review

OBJECTIVES

Intravenous immunoglobulin (IVIg) is used for treatment of acute neurologic conditions such as Guillain-Barre syndrome, chronic inflammatory demyelinating polyradiculoneuropathy relapse, and myasthenia gravis exacerbation. Precision dosing (adjusted or ideal body weight) is proposed to conserve IVIg. There have been no published studies comparing clinical outcomes in traditional dosing (actual body weight) with precision dosing. In 2014, our institution began dosing patients with precision dosing. This decision was largely performed by administration rather than physicians' preference. We sought to analyze our retrospective data to understand the change in dosing methods with neurologic outcomes.

METHODS

We performed a retrospective review of all patients hospitalized at a single center who received IVIg for myasthenia gravis, Guillain-Barre syndrome, and chronic inflammatory demyelinating polyradiculoneuropathy from January 2010 to October 2017. We collected baseline information and clinical outcomes including mortality, readmission, need for second rescue treatment, length of stay, discharge disposition, treatment-related adverse events, and modified research council posttreatment sum score.

RESULTS

Length of stay was significantly shorter with precision dosing. There was no statistically significant difference in discharge disposition, readmission, rescue treatment, or modified research council posttreatment sum score with precision dosing.

CONCLUSION

Precision dosing did not adversely affect short-term neurologic outcomes.

Mitigating the risk of COVID-19 exposure by transitioning from clinic-based to home-based immune globulin infusion

PURPOSE

Intravenous immune globulin (IVIG) therapy is used in patients with hypogammaglobulinemia to lower the risk of infections. IVIG and subcutaneous IVIG (SCIG) therapy have been to shown to be safe and effective when administered as clinic-based infusions. Concern from both patients and providers for increased transmission of the coronavirus disease 2019 (COVID-19) virus to immunosuppressed patients with scheduled medical visits and procedures made it necessary for us to reassess our process of how we manage patient care in general and chronic clinic infusions in particular. Here we describe our experience of transitioning patients from clinic-based to home based IVIG and/or SCIG infusions to decrease the risk of COVID-19 exposure.

METHODS

Criteria were developed to identify high-risk immunosuppressed patients who would be appropriate candidates for potential conversion to home based IVIG infusions. Data were collected via chart review, and cost analysis was performed using Medicare Part B reimbursement data. A patient outcome questionnaire was developed for administration through follow-up phone calls.

RESULTS

From March to May 2020, 45 patients met criteria for home-based infusion, with 27 patients (60%) agreeing to home-based infusion. Posttransition patient outcomes assessment, conducted in 26 patients (96%), demonstrated good patient understanding of the home-based infusion process. No infusion-related complications were reported, and 24 patients (92%) had no concerns about receiving future IVIG and/or SCIG doses at home. No patient tested positive for COVID-19 during the study period. Clinic infusion visits decreased by 26.6 visits per month, resulting in a total of 106 hours of additional available infusion chair time per month and associated cost savings of $12,877.

CONCLUSION

Transition of clinic based to home based IVIG/SCIG infusion can be successfully done to decrease potential exposure during a pandemic in a high-risk immunosuppressed population, with no impact on patient satisfaction, adherence, or efficacy. The home-based infusion initiative was associated with a reduction in costs to patients and an increase in available chair time in the infusion clinic.

A systematic review of population pharmacokinetic analyses of polyclonal immunoglobulin G therapy

BACKGROUND

Population pharmacokinetics (popPK) using the nonlinear mixed-effect (NLME) modeling approach is an essential tool for guiding dose individualization. Several popPK analyses using the NLME have been conducted to characterize the pharmacokinetics of immunoglobulin G (IgG).

OBJECTIVE

To summarize the current information on popPK of polyclonal IgG therapy.

METHOD

A systematic search was conducted in the PubMed and Web of Science databases from inception to December 2020. Additional relevant studies were also included by reviewing the reference list of the reviewed articles. All popPK studies that employed the NLME modeling approach were included and data were synthesized descriptively.

RESULTS

This review included seven studies. Most of the popPK models were developed in patients with primary immunodeficiency (PID). IgG pharmacokinetics was described as a two-compartment model in five studies, while it was described as a one-compartment model in two other studies. Among all tested covariates, weight was consistently identified as a significant predictor for clearance (CL) of IgG. Whereas, weight and disease type were found to be significant predictors for the volume of distribution in central compartment (Vc). In a typical 70 kg adult, the median estimated values of Vc and CL were 4.04 L and 0.144 L/day, respectively. The between subject variability of Vc was considered large. Only two studies evaluated their models using external data.

CONCLUSIONS

Seven popPK studies of IgG were found and discussed, with only weight being a significant covariate across all studies. Future studies linking pharmacokinetics with pharmacodynamics in PID and other patient populations are required.

Intravenous Immune Globulin (IVIG) for Treatment of Autoimmune Heparin-Induced Thrombocytopenia: A Systematic Review

OBJECTIVE

To evaluate intravenous immune globulin (IVIG) for autoimmune heparin-induced thrombocytopenia (aHIT), including platelet recovery, IVIG dose, dosing weight, IVIG product used, and complications reported.

DATA SOURCES

PubMed and EMBASE were searched from inception through June 21, 2020. Search terms included heparin-induced thrombocytopenia, HIT, intravenous immune globulin, IVIG, autoimmune HIT, aHIT, and immune globulin.

STUDY SELECTION AND DATA EXTRACTION

Patients administered IVIG for HIT and diagnosed by immunoassay (optical density ≥2) or positive activation assay were included.

DATA SYNTHESIS

Twenty-four cases were reviewed; 92% had persistent aHIT. Time to IVIG administration post-nonheparin anticoagulant initiation was 9 days (median). Most common IVIG cumulative dose was 2 g/kg (dosed as 1 g/kg/d for 2 consecutive days); 75% had a favorable platelet increase (≥50 × 10⁹/L) within 5 days of initial IVIG dosing.

RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE

aHIT is characterized by critically low platelets, thrombosis, and a persistent delay in platelet recovery despite treatment with a nonheparin anticoagulant. An immunoassay and subsequent confirmatory activation assay (at low, high, and 0 IU/mL unfractionated heparin levels) is recommended to confirm diagnosis. Patients nonresponsive to nonheparin anticoagulants within 5 days of initiation should be evaluated for IVIG treatment (2 g/kg cumulative dose). More data are needed to clarify appropriate IVIG dosing weight, although based on current published literature, it is recommended to use actual body weight.

CONCLUSIONS

Data reported support use of IVIG as adjunctive therapy for patients with aHIT. Judicious IVIG use based on key clinical and laboratory findings is critical.

Considerations for Optimizing Dosing of Immunoglobulins Based on Pharmacokinetic Evidence

Immunoglobulins (IGs) are widely used for the treatment of immunodeficiency syndromes and several autoimmune diseases. In neonates, IGs have been used for the treatment of alloimmune thrombocytopenia, in neonatal infections and in the rare cases of neonatal Kawasaki disease. This review aims to examine the various dosing regimens of IGs following intravenous (IV) and subcutaneous (SC) administration, pharmacokinetics (PK) of IGs, and the importance of trough values for the prevention of infections in patients with primary immune deficiency (PID). The review also focuses on the mechanism of catabolism of IGs and the impact on the half-life of IGs. Data and reviews were obtained from the literature and the FDA package inserts. The authors suggest that for dosing, the PK of IGs should be evaluated on the baseline-corrected concentrations since this approach provides an accurate estimate of half-life and clearance of IGs. We also suggest employing clearance as a primary PK parameter for dosing determination of IGs. We suggest that IV dosing would be more effective if given more frequently to adjust for the increased clearance at high doses and because the baseline-corrected half-life is much shorter than the baseline-uncorrected half-life. Regarding SC administration, the dose should be adjusted based on the absolute bioavailability (determined against IV dosing) of the product. Finally, we highlight clinical and PK data gaps for optimum and individualized dosing of IGs.

Optimization of intravenous immune globulin use at a comprehensive cancer center

Purpose

Intravenous immune globulin (IVIG) is a high-cost medication used in a diverse range of settings. At many institutions, IVIG is dosed using total body weight (TBW). Recent evidence suggests that alternative dosing weights reduce waste without compromising clinical outcomes. The objective of this study was to quantify the waste reduction potential generated through the use of alternative IVIG dosing weights.

Methods

We performed a retrospective analysis of all IVIG doses administered from January 2011 through January 2016 to adults (≥18 years). TBW and height at the time of administration were used to calculate prescribed dose (g/kg), ideal body weight (IBW), and adjusted body weight (AdjBW). Three dosing methods were analyzed, as follows: use of AdjBW if TBW is >120% IBW (method 1), AdjBW for all doses (method 2), and IBW for all doses (method 3). Outcomes included potential IVIG use averted, direct drug cost savings, and reductions in outpatient infusion times for each method.

Results

A total of 9,918 doses were administered to 2,564 patients over 5 years, representing an average usage of 75,994 g/year. If dosing methods 1, 2, and 3 had been used, the annual use of IVIG would have decreased by 21.9% (16,658 g/year, p < 0.001), 24.2% (18,371 g/year, p < 0.001), and 35.9% (27,252 g/year, p < 0.001), respectively. This translates into average annual cost differences of $2.37 million, $2.62 million, and $3.89 million and average annual outpatient infusion time savings of 841 hours, 920 hours, and 1,366 hours, respectively.

Conclusion

IVIG dosing optimization through use of alternative dosing weights represents a significant source of waste reduction and cost reduction.

Outcomes Associated With Standardized Ideal Body Weight Dosing of Intravenous Immune Globulin in Hospitalized Patients: A Multicenter Study

Background: There are limited outcomes data for ideal body weight (IBW)-based dosing of intravenous immune globulin (human, IVIG) in hospitalized patients. Objective: To investigate clinical outcomes associated with a standardized change from total body weight to IBW-based dosing of IVIG. Methods: This was a retrospective, multicenter, pre-post sequential period analysis. Data from pre-implementation and post-implementation of an IBW-based dosing strategy for IVIG were collected in 2-year periods (October 1, 2012, to August 31, 2014, and October 2, 2014, to October 1, 2016, respectively). The primary outcome was incidence of 30-day hospital readmission. Length of stay (LOS) was analyzed as a secondary outcome. Results: For the 2 study periods, 297 patients were included for analysis. Both groups had similar demographics, IVIG indications, and body weight measurements, but the post-implementation period had a lower median grams per dose as compared with the pre-implementation period (40 vs 30 g, P ≤ 0.01). 30-Day hospital readmission rates were not significantly different (4% vs 9%, P = 0.07). In-hospital all-cause mortality was also not statistically significant (7.7% vs 3.4%, P = 0.11). The 2 study groups had a similar median hospital LOS (8 vs 7.6 days, P = 0.27). Conclusion and Relevance: The implementation of a standardized IBW IVIG dosing strategy was not associated with a statistically significant increase in 30-day hospital readmission or LOS but was associated with significantly fewer grams per dose given. Application of these data may aid in decreasing institutional drug spend without affecting patient outcomes. However, the study was underpowered, and further investigation is necessary to validate these findings.

Intravenous immunoglobulin for the treatment of intractable cholangitis after Kasai portoenterostomy in biliary atresia patients

OBJECTIVE

To assess the efficacy of intravenous immunoglobulin (IVIG) as add-on treatment for intractable cholangitis (IC) after Kasai portoenterostomy (KPE) in biliary atresia (BA) patients.

METHODS

113 BA patients who had one or more episodes of cholangitis after KPE were recruited in this study. According to whether response to routine conservative treatment, all patients were divided into IC group and simple cholangitis (SC) group. Meanwhile, patients with IC subdivided into IVIG group and control group according to whether application of IVIG.

RESULTS

The IC group had higher serum procalcitonin (PCT) (P = 0.014), C-reactive protein (CRP) (P = 0.023), and γ-Gltamyltranspeptidase (γ-GGT) (P = 0.031) level than the SC group. The IVIG group had shorter duration of fever after treatment (P = 0.011) and length of hospital stay (P = 0.018) than the control group. The time until recurrent episode of cholangitis was significant longer in IVIG group than in control group (P = 0.019).

CONCLUSIONS

IVIG as add-on treatment may be an effective treatment for the cholangitis acute episode, and we conclude by calling for more prospective studies to attest to the role of IVIG in the treatment of cholangitis.