Efficacy and safety of a new, chromatographically purified rhesus (D) immunoglobulin

Therapeutic proteins: developments, progress, challenges, and future perspectives

Proteins are considered magic molecules due to their enormous applications in the health sector. Over the past few decades, therapeutic proteins have emerged as a promising treatment option for various diseases, particularly cancer, cardiovascular disease, diabetes, and others. The formulation of protein-based therapies is a major area of research, however, a few factors still hinder the large-scale production of these therapeutic products, such as stability, heterogenicity, immunogenicity, high cost of production, etc. This review provides comprehensive information on various sources and production of therapeutic proteins. The review also summarizes the challenges currently faced by scientists while developing protein-based therapeutics, along with possible solutions. It can be concluded that these proteins can be used in combination with small molecular drugs to give synergistic benefits in the future.

Case report: Double filtration plasmapheresis (DFPP) for severe rhesus-D alloimmunization in two pregnant patients

Maternal erythrocyte alloimmunization is one of the most important causes of fetal anemia. The standard treatment for anemic fetuses is intrauterine blood transfusion (IUT). However, IUT may have adverse effects, particularly before 20 weeks of gestation. In this report, two women who had previously had severely affected alloimmunized pregnancy developed high titers of anti-D antibodies before 20 weeks of gestation. Ultrasound Doppler showed severe fetal anemia, and intrauterine transfusion was expected to be unavoidable. To prolong pregnancy to a gestation in which intravascular IUT was possible, we used repeated double filtration plasmapheresis (DFPP) as a rescue therapy. The titers of IgG-D, IgG-A, and IgG-B decreased after DFPP treatment. One woman successfully prolonged pregnancy until 20 weeks of gestation. Subsequently, she underwent four cycles of IUTs and delivered at 30 weeks of gestation by emergency cesarean section due to fetal bradycardia during the fifth intrauterine transfusion. The other woman successfully delayed intrauterine transfusion until 26 weeks of gestation. The favorable results of the two patients indicate that DFPP may be an effective and safe treatment modality for RhD immunity in pregnant women. Moreover, DFPP is potentially helpful for reducing the occurrence of ABO hemolytic disease in neonates due to the clearance of IgG-A and IgG-B antibodies (e.g., O pregnant women harbored A/B/AB neonates). However, more clinical trials are needed to verify the results.

Missed RHIG administration to postpartum patients in two health systems: an unrecognized patient safety risk

BACKGROUND

Maternal-fetal Rh-alloimmunization is a rare but potentially fatal event, most often caused by maternal exposure to D-antigen-presenting Rh-positive erythrocytes at the time of delivery. Prophylaxis with anti-D immune globulin is highly effective with a low side-effect profile and results in a dramatically decreased risk of alloimmunization. Postpartum anti-D immune globulin prophylaxis is recommended by national societies to reduce Rh-alloimmunization. We hypothesized that a small number of postpartum patients do not receive prophylaxis as indicated.  

OBJECTIVE

We investigated patients in 2 separate health systems that did not receive indicated prophylaxis and devised a suite of Electronic Health Record interventions to prevent future errors.

STUDY DESIGN

We reviewed charts retrospectively from Electronic Health Record data of 2 urban academic health systems, the MetroHealth System and Oregon Health & Science University. We identified all Rh-negative postpartum patients and their infants delivering from 2014 to 2019. The primary outcome was the proportion of postpartum patients not receiving indicated anti-D immune globulin prophylaxis. Once cases of missed anti-D immune globulin prophylaxis were identified, we reviewed individual charts to determine the relevant clinical circumstances and potential causes for error.

RESULTS

Of 29,801 deliveries over 5 years (15,444 at MetroHealth System and 14,357 at Oregon Health & Science University), there were 3087 Rh-negative postpartum patients, of whom 7 were alloimmunized and ineligible for prophylaxis. Anti-D immune globulin was indicated for 2162 (70.0%) women as they delivered an Rh-positive infant. A total of 37 indicated patients did not receive postpartum anti-D immune globulin. Twenty patients were offered prophylaxis and declined. We missed a total of 17 opportunities, thus our institutions appropriately offered indicated anti-D prophylaxis to 99.2% of patients over a period of 5 years. Of the 17 true misses, anti-D immune globulin was ordered for some patients, whereas others did not have an anti-D immune globulin order placed. A toolkit in the Electronic Health Record consisting of decision-support hard stops, automated documentation, and longitudinal reporting was implemented at the MetroHealth System in the year after its inception. The Toolkit identified and helped prevent 4 potential misses, resulting in a 100% anti-D prophylaxis rate at the MetroHealth System.

CONCLUSION

Given the serious nature of Rh-alloimmunization, we believe missed prophylaxis should be a never event. Through examination of our current processes, we identified areas of improvement and developed a Postpartum Anti-D Immune Globulin Prophylaxis Electronic Health Record Toolkit, which showed improvement in administration rates. Such a toolkit has the potential to identify patients appropriately and avoid missed anti-D immune globulin prophylaxis events.

Antenatal and postpartum prevention of Rh alloimmunization: A systematic review and GRADE analysis

BACKGROUND

Existing systematic reviews of Rh immunoprophylaxis include only data from randomized controlled trials, have dated searches, and some do not report on all domains of risk of bias or evaluate the certainty of the evidence. Our objective was to perform an updated review, by including new trials, any comparative observational studies, and assessing the certainty of the evidence using the GRADE framework.

METHODS

We searched MEDLINE, Embase and the Cochrane Library from 2000 to November 26, 2019. Relevant websites and bibliographies of systematic reviews and guidelines were searched for studies published before 2000. Outcomes of interest were sensitization and adverse events. Risk of bias was evaluated with the Cochrane tool and ROBINS-I. The certainty of the evidence was performed using the GRADE framework.

RESULTS

Thirteen randomized trials and eight comparative cohort studies were identified, evaluating 12 comparisons. Although there is some evidence of beneficial treatment effects (e.g., at 6-months postpartum, fewer women who received RhIg at delivery compared to no RhIg became sensitized [70 fewer sensitized women per 1,000 (95%CI: 67 to 71 fewer); I2 = 73%]), due to very low certainty of the evidence, the magnitude of the treatment effect may be overestimated. The certainty of the evidence was very low for most outcomes often due to high risk of bias (e.g., randomization method, allocation concealment, selective reporting) and imprecision (i.e., few events and small sample sizes). There is limited evidence on prophylaxis for invasive fetal procedures (e.g. amniocentesis) in the comparative literature, and few studies reported adverse events.

CONCLUSION

Serious risk of bias and low to very low certainty of the evidence is found in existing RCTs and comparative observational studies addressing optimal effectiveness of Rh immunoprophylaxis. Guideline development committees should exercise caution when assessing the strength of the recommendations that inform and influence clinical practice in this area.

Clinical value of different anti-D immunoglobulin strategies for preventing Rh hemolytic disease of the fetus and newborn: A network meta-analysis

BACKGROUND

Several anti-D immunoglobulin strategies exist for preventing Rh hemolytic disease of the fetus and newborn. This study systematically assessed the clinical value of those therapeutic strategies.

METHODS

The Web of Science, PubMed, EMBASE, China National Knowledge Infrastructure (CNKI) and Wanfang databases were searched for eligible studies that evaluated the value of different anti-D immunoglobulin strategies in preventing maternal anti-D antibody sensitization. Combined odds ratios (ORs) and their 95% confidence intervals (CIs) were calculated. The network meta-analysis was conducted using Stata 14.2 and WinBUGS 1.4.3 software.

RESULTS

Twenty-four original studies involving 64860 patients were included. Among all therapeutic measures, injecting 300 μg anti-D immunoglobulin at 28 and 34 gestational weeks (antenatal 5/E) appeared to be the most effective measure for preventing maternal antibody sensitization (surface under the cumulative ranking curve [SUCRA] = 96.8%), while a single injection at 28 gestational weeks (SUCRA = 89.2%) was the second most effective. Administering no injection or a placebo (SUCRA = 0.0%) was the least effective intervention measure.

CONCLUSION

Among the therapeutic measures, antenatal 5/E appeared to be the best method for reducing the positive incidence of anti-D antibodies in the maternal serum; thus, it may be the most effective treatment for preventing fetal hemolytic disease.

Single dose v two-dose antenatal anti-D prophylaxis: a randomised controlled trial

OBJECTIVE

To compare rates of detectability of circulating Rh(D)-immunoglobulin (anti-D) at delivery with single and two-dose antenatal anti-D prophylaxis (RAADP) regimens; to compare compliance with the two regimens.

DESIGN

Open label, randomised controlled trial between May 2013 and November 2015.

SETTING, PARTICIPANTS

277 women who attended a tertiary obstetric referral hospital in Perth for antenatal care and were at least 18 years of age, less than 30 weeks pregnant and yet to receive RAADP, Rh(D)-negative (negative antibody screen), and who intended to deliver their baby at the hospital. Exclusion criteria were prior anti-D sensitisation, any contraindication of anti-D administration, and a history of isolated IgA deficiency.

INTERVENTIONS

One 1500 IU anti-D dose at 28 weeks of pregnancy (single dose regimen); two doses of 625 IU each at 28 and 34 weeks of pregnancy (two-dose regimen).

MAIN OUTCOME MEASURES

The primary outcome was the proportion of women with detectable anti-D levels at delivery; the secondary outcome was compliance with the allocated RAADP regimen.

RESULTS

Circulating anti-D was detectable at delivery in a greater proportion of women in the two-dose group (111 of 129, 86%) than in the single dose group (70 of 125, 56%; P < 0.001). Compliance was not significantly different between the single dose (86 of 138, 61%) and two-dose groups (70 of 139, 50%; P = 0.06).

CONCLUSIONS

The two-dose RAADP schedule currently recommended in Australia provides better protection against Rh(D) sensitisation than a one-dose regimen.

TRIAL REGISTRATION

Australian and New Zealand Clinical Trials Registry (ACTRN12613000661774).

Rh(O)D immune globulin products for prevention of alloimmunization during pregnancy

PURPOSE

The pharmacologic properties of Rhesus (Rh) immune globulin (RhIG) and clinical data on its effectiveness in preventing Rh-antigen alloimmunization in pregnant women are reviewed.

SUMMARY

RhIG is a human plasma derivative that targets red blood cells (RBCs) positive for Rh(O) antigen (also called D antigen). In the United States and other countries, the widespread use of RhIG has markedly reduced the occurrence of hemolytic disease of the fetus and newborn (HDFN), a devastating condition caused by D-antigen sensitization of a pregnant woman via exposure to fetal RBCs (usually during detachment of the placenta in labor) that results in a maternal immune response leading to severe hemolysis in the fetus. Routine administration of RhIG at 26-30 weeks' gestation and again within 72 hours of delivery has been shown to be highly effective in preventing maternal Rh alloimmunization, with very low rates of D-antigen sensitization (in the range of 0-2.2%) reported in multiple studies of at-risk women. The four RhIG products currently available in the United States have common clinical indications but differ in certain attributes. Pharmacists can play an important role in guiding other clinicians on the rationale for the use of RhIG, important differences between products, and appropriate timing of RhIG therapy.

CONCLUSION

Routine administration of RhIG to women at risk for Rh alloimmunization is clinically effective and has made HDFN a rare clinical event. The available RhIG products are not the same and should be carefully reviewed to ensure that they are administered safely.

Efficacy and safety of intravenous anti-D immunoglobulin (Rhophylac®) in chronic immune thrombocytopenic purpura

OBJECTIVES

This Phase III study examined the efficacy and safety of Rhophylac (CSL Behring AG, Bern, Switzerland), a highly pure, liquid-stable anti-D preparation, in chronic immune thrombocytopenic purpura (ITP).

MATERIALS AND METHODS

Ninety-eight patients (96 adults, two adolescents) with chronic ITP and platelet counts < 30 x 10(9)/l received a single intravenous injection of 50 microg/kg bodyweight Rhophylac.

RESULTS

A response (defined as an increase in platelet count by >or= 20 x 10(9)/l to >or= 30 x 10(9)/l in the first 15 days after treatment) was seen in 66% of patients. Mean time to response was 3.1 +/- 3.0 days, and mean duration of response was 19.2 +/- 1.1 days for responders. The most frequent drug-related adverse events were chills, pyrexia, an increase in bilirubin, and headache; events were mainly mild or moderate. there was no severe hemolysis or renal failure.

CONCLUSION

rhophylac is well tolerated and efficacious in chronic itp.

Intramuscular versus intravenous anti-D for preventing Rhesus alloimmunization during pregnancy

BACKGROUND

Antibodies to the red cell Rhesus D (RhD) antigen can be produced during pregnancy in a RhD-negative mother carrying a RhD-positive fetus, in particular following feto-maternal haemorrhage at birth or following any procedure that may cause feto-maternal haemorrhage. While the first baby is usually not harmed, these antibodies may cause haemolytic disease of the fetus/newborn (HDFN) in subsequent RhD-positive babies. RhD incompatibility is a major cause of HDFN.To reduce the risk of HDFN, anti-D is given to RhD-negative mothers at 28 or 30 weeks of pregnancy and within 72 hours of potential maternal exposure to fetal red cells. Anit-D is currently available in both intramuscular (IM) and intravenous (IV) preparations.

OBJECTIVES

To compare the efficacy and effectiveness of IM versus IV anti-D IgG in preventing RhD alloimmunization in RhD-negative pregnant women.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (30 September 2012).

SELECTION CRITERIA

Randomized controlled trials, quasi-randomized trials and cluster-randomized trials comparing IM and IV anti-D for preventing RhD alloimmunization in RhD-negative pregnant women.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trials for inclusion and assessed trial quality. Two review authors extracted data. Data were checked for consistency by both authors.

MAIN RESULTS

Two studies involving 447 (with sample sizes 14 and 432) RhD negative women were included. The studies compared IM and IV administration of anti-D prophylaxis. In both studies the women received a 1500 IU (300 microgram) dose of Rhophylac during week 28 of gestation. There was no incidence of RhD alloimmunization in either of the studies, as the sample size was insufficient for meaningful comparison of this uncommon outcome. One of the studies found that the mean anti-D IgG concentrations after IV and IM administration differed up to seven days (36.1 (2.6) ng/mL IV; 19.8 (8.7) ng/mL IM on day seven). However, from two to three weeks post-administration, the concentrations were similar for both routes of administration. None of the women involved in the studies developed antibodies against the RhD antigen.

AUTHORS' CONCLUSIONS

It appears that IM and IV administration of anti-D are equally effective. The number of included studies and the number of participants are not enough to assess whether there are any differences. Anti-D can be administered by IM or IV injection. The choice of IM or IV route of administration will depend on the available preparations, the dose to be administered and also on the patients' preferences. This review found insufficient information upon which to guide practice due to the limited number of included studies, small sample sizes and methodological limitations.

Protein therapeutics: a summary and pharmacological classification

Once a rarely used subset of medical treatments, protein therapeutics have increased dramatically in number and frequency of use since the introduction of the first recombinant protein therapeutic--human insulin--25 years ago. Protein therapeutics already have a significant role in almost every field of medicine, but this role is still only in its infancy. This article overviews some of the key characteristics of protein therapeutics, summarizes the more than 130 protein therapeutics used currently and suggests a new classification of these proteins according to their pharmacological action.

The kinetics of routine antenatal prophylactic intramuscular injections of polyclonal anti-D immunoglobulin

OBJECTIVE

To observe the pharmacokinetics of intramuscular anti-D immunoglobulin (IgG) given for routine antenatal prophylaxis.

DESIGN

Prospective observational study.

SETTING

Maternity unit and antenatal serology laboratory in a district teaching hospital.

POPULATION

Forty-five rhesus-D-negative pregnant women not sensitised to RhD.

METHODS

Serial serum quantitations of anti-D IgG following the intramuscular injections of anti-D IgG 100 microg (500 IU) at 28 and 34 weeks of gestation. Anti-D IgG concentrations were assayed with the RFA-300 continuous flow analyser.

MAIN OUTCOME MEASURES

The kinetic profile and duration of detectable anti-D IgG in maternal serum following the first and second injections of anti-D IgG.

RESULTS

For the 43 women in whom serial data were collected, there were no detectable differences between pregnancies with an RhD-positive (26) or -negative (17) fetus. Maximum IgG concentrations were detected two to five days following the first anti-D IgG injection and ranged between 0 and 28 ng/mL. Only 30% of women still undelivered at 40 weeks of gestation had detectable IgG at 2 ng/mL or greater. There was a significant relationship between higher maximum values and low maternal surface body area (R2 = 0.204, P = 0.002), but this did not influence duration of persistent IgG.

CONCLUSION

Using previously published data, 70% women are not adequately protected with anti-D IgG 12 weeks after the first prophylactic injection. Despite this, previous clinical results suggest that the antenatal prophylaxis schedule used provides adequate protection and that the recommendation for the lowest concentration of protective anti-D IgG antibody levels currently in use is probably overestimated.