Developmental and peri-postnatal study in cynomolgus monkeys with belimumab, a monoclonal antibody directed against B-lymphocyte stimulator

Considering belimumab during pregnancy: A more viable option over time

OBJECTIVE

To share our experience with belimumab in lupus pregnant women and to review the relevant published literature on its use in this scenario.

METHODS

A prospective observational study of pregnant patients with lupus was conducted. Additionally, MEDLINE and EMBASE databases were searched, and a secondary hand search of the literature was performed. Studies were evaluated and visualised descriptively.

RESULTS

Sixteen pregnancies of 12 lupus women were included, six (involving eight pregnancies) received belimumab throughout their illness, five of them during some period of gestation. In this group, there was one miscarriage, one elective termination and seven live foetuses (including two live twins). There was one type I intrauterine growth retardation, and a preterm pregnancy due to premature rupture of membranes (PPROM). One mild lupus flare was detected. There were no cases of pre-eclampsia, gestational diabetes mellitus or hypertension. All neonates had normal Apgar scores at birth, none needed critical care. There were no congenital anomalies. After the search, we identified 10 case reports and case series, and five registries. Among the 39 reported cases (41 pregnancies), there were 5 PPROM, 4 pre-eclampsia, and 1 eclampsia. All women made full recoveries. Nineteen new-borns had low birth weight. There were no malformations. While registries did not indicate an increased risk of birth defects or pregnancy loss, there was a higher risk of neonatal infections.

CONCLUSIONS

Belimumab may be an option for pregnant women with difficult-to-control lupus. Further research is needed to confirm the absence of association between belimumab and foetal harm.

Dilemma of belimumab therapy (dis)continuation during pregnancy: Results of a retrospective study in eudravigilance

INTRODUCTION

The first biologic authorized for systemic lupus erythematosus (SLE) up to this date, belimumab, is currently not recommended for use during pregnancy due to lack of data. Provided that the health of the child begins with the health of the mother, pregnant patients face the dilemma of cessation or continuation of belimumab. If belimumab is stopped, there will be a risk of SLE flare and its consequences for the mother and the foetus. Continuation is also not optimal because of the lack of knowledge on safety for use during pregnancy.

AIM

To compare the reported foetal outcomes in SLE patients who stopped scheduled belimumab within the first trimester (group A) and those who continued scheduled belimumab during the first trimester or thereafter (group B).

MATERIAL AND METHOD

All belimumab-exposed pregnancy-related reports were extracted from the EudraVigilance (EV) database until March 11th, 2021. After case review, repeated cases, uninformative reports, non-medical elective abortions and foetal chromosomal abnormalities were excluded. Included pregnancies were divided into two groups (group A and B, as described above). Foetal outcomes were divided into live birth or foetal death (due to miscarriage or stillbirth) and were compared between both groups. Furthermore, neonatal outcomes, such as reporting rates of preterm birth, low birth weight and major congenital malformations were compared.

RESULTS

No statistical difference in foetal death was observed between group A and B (reported numbers (%) = 32 (46.4) and 11 (52.4), respectively). Odds ratio (OR, [95% Confidence Intervals (CIs)]) of foetal death in group B compared to group A was 1.27 [0.48, 3.32]. Reporting rates of preterm birth and low birth weight were higher - though not statistically different - in group A.

CONCLUSION

The positive results of our study are supportive for the continuation of belimumab during pregnancy. Since the analysis is based on spontaneous reports/retrospective data, additional studies are needed to confirm the results.

Belimumab use during pregnancy: a summary of birth defects and pregnancy loss from belimumab clinical trials, a pregnancy registry and postmarketing reports

OBJECTIVE

Describe available data on birth defects and pregnancy loss in women with systemic lupus erythematosus (SLE) exposed to belimumab.

METHODS

Data collected from belimumab clinical trials, the Belimumab Pregnancy Registry (BPR), and postmarketing/spontaneous reports up to 8 March 2020 were described. Belimumab exposure timing, concomitant medications and potential confounding factors were summarised descriptively.

RESULTS

Among 319 pregnancies with known outcomes (excluding elective terminations), 223 ended in live births from which birth defects were identified in 4/72 (5.6%) in belimumab-exposed pregnancies and 0/9 placebo-exposed pregnancies across 18 clinical trials, 10/46 (21.7%) belimumab-exposed pregnancies in the BPR prospective cohort (enrolled prior to pregnancy outcome) and 0/4 belimumab-exposed pregnancies in the BPR retrospective cohort (enrolled after pregnancy outcome), and 1/92 (1.1%) in belimumab-exposed pregnancies from postmarketing/spontaneous reports. There was no consistent pattern of birth defects across datasets. Out of pregnancies with known outcomes (excluding elective terminations), pregnancy loss occurred in 31.8% (35/110) of belimumab-exposed women and 43.8% (7/16) of placebo-exposed women in clinical trials; 4.2% (2/48) of women in the BPR prospective cohort and 50% (4/8) in the BPR retrospective cohort; and 31.4% (43/137) of belimumab-exposed women from postmarketing/spontaneous reports. All belimumab-exposed women in clinical trials and the BPR received concomitant medications and had confounding factors and/or missing data.

CONCLUSIONS

Observations reported here add to limited data published on pregnancy outcomes following belimumab exposure. Low numbers of exposed pregnancies, presence of confounding factors/other biases, and incomplete information preclude informed recommendations regarding risk of birth defects and pregnancy loss with belimumab use.

Belimumab use during pregnancy: Interim results of the belimumab pregnancy registry

BACKGROUND

Belimumab is approved for active, autoantibody-positive systemic lupus erythematosus (SLE) and lupus nephritis, but limited data exist regarding its use in pregnancy. The Belimumab Pregnancy Registry (BPR, GSK Study BEL114256; NCT01532310) was created to evaluate pregnancy and infant outcomes following belimumab exposure.

METHODS

Individuals with SLE exposed to belimumab from 4 months before and/or during pregnancy can enroll into the BPR. The primary outcome is major birth defects; secondary outcomes include miscarriages, stillbirths, elective termination, pre-term birth, neonatal death, small for gestational age, and adverse infant outcomes during the first year of life. Belimumab exposure timing, concomitant medications, and other potential confounding factors are also collected. Data up to March 8, 2021, are reported descriptively.

RESULTS

From an expected sample size target of 500 prospective pregnancies with a known outcome, only 55 were enrolled in the study. Among these, two pregnancy losses and 53 pregnancies with a live birth outcome were reported. Ten of the 53 live birth pregnancies resulted in a major birth defect. Ten pregnancies were enrolled after the pregnancy outcome occurred and were examined retrospectively (four live births with no defects, four miscarriages, and two elective terminations). There was no indication or pattern of birth defects associated with belimumab.

CONCLUSIONS

Low recruitment numbers for the BPR and incomplete information limit the conclusions regarding belimumab exposure during pregnancy. There was no pattern or common mechanism of birth defects associated with belimumab within the BPR data.

A case report of two systemic lupus erythematosus pregnancies with early placental exposure to belimumab: Case report with review

Since its approval for the management of systemic lupus erythematosus (SLE), belimumab has been widely used. However, its pregnancy safety profile has been underinvestigated. We present the pregnancy outcomes of two cases of early placental exposure to belimumab and summarise the pregnancy outcomes in previous reports regarding placental exposure to belimumab. Case 1 describes a 27-year-old woman with an 18-year history of SLE and lupus nephritis class III. We introduced belimumab 19 months prior to conception to control her proteinuria and discontinued its use at 5 weeks and 5 days of gestation. Her lupus activity was stable throughout pregnancy, and at 37 weeks and 1 day of gestation, she delivered a healthy girl with no anomaly. At delivery, the girl was small for gestational age, but at the 1-year follow-up, there was no delay in her growth or any serious infection. Case 2 describes a 32-year-old woman with a 15-year history of SLE. We introduced belimumab 9 months prior to conception and discontinued its use at 7 weeks and 1 day of gestation. Although her lupus was well controlled without belimumab, a missed abortion occurred, which was possibly due to foetal factors. Although there is accumulating data on the safety of belimumab use during pregnancy, it seems necessary to cautiously use this medication in pregnant women, until further analyses are conducted.

Different pregnancy outcomes in patients with systemic lupus erythematosus treated with belimumab

OBJECTIVES

Systemic lupus erythematosus (SLE) predominantly occurs in women of child-bearing age. Selecting drugs for pregnant SLE patients has always been a difficult choice. Although there have been several reports of safety of belimumab in SLE patients during pregnancy, the data are far from sufficient.

METHODS

We report on 4 cases of belimumab exposure in pregnant SLE patients. We also summarized 6 case reports and case series which were previously published. Further, we compared the different outcomes among SLE patients and their babies who continued with belimumab during pregnancy with those who discontinued belimumab in early pregnancy.

RESULTS

Two cases discontinued belimumab in the early pregnancy, while the other two received belimumab until the late pregnancy. All the four women tolerated belimumab. Newborns have all developed normally and continue without complications during 1 year of follow-up.

CONCLUSION

In this small case series, we found that belimumab was well tolerated in pregnant SLE patients. There were no safety signals for the mothers or their babies.

Pregnancy in patients with systemic lupus erythematosus: a systematic review

Systemic lupus erythematosus (SLE)-a most common disorder in women of reproductive age-has been described to be associated with adverse pregnancy outcomes. Despite the increased health risks for the mother (preeclampsia, lupus flare, arterial hypertension, gestational diabetes mellitus and thrombotic risk when antiphospholipid antibodies are present) and fetus (miscarriage, stillbirth, premature birth, intrauterine growth restriction and neonatal lupus), the majority of patients can deliver healthy neonates. With appropriate management by a multidisciplinary team, composing rheumatologists, obstetricians and neonatologists, women with SLE can achieve better pregnancy outcomes by monitoring associated predictive indicators, raising major concern for severe complications and somewhat early delivery if necessary. In this review, we summarize the latest advances in secondary infertility and pregnancy-related risk perception for lupus patients, with an emphasis on the safety of biological agents (mainly belimumab and rituximab) and traditional therapeutic regimens.

Optimizing reproductive health management in lupus and Sjogren's syndrome

PURPOSE OF REVIEW

People with childbearing capacity who are diagnosed with systemic lupus erythematosus (SLE) and Sjogren's syndrome (SS) have specific and important reproductive health considerations.

RECENT FINDINGS

Recommendations from the European League Against Rheumatism (EULAR) and the American College of Rheumatology (ACR) provide rheumatologists and other clinicians with guidance for reproductive health management of patients with rheumatic diseases. Patient-centered reproductive health counseling can help clinicians to operationalize the EULAR and ACR guidelines and enhance patient care.

SUMMARY

Disease activity monitoring, risk factor stratification, and prescription of pregnancy-compatible medications during pregnancy help to anticipate complications and enhance pregnancy outcomes in SLE and SS. Assisted reproductive technologies are also safe among people with well-controlled disease. Safe and effective contraceptive methods are available for patients with SLE and SS, and pregnancy termination appears to be safe among these patients.

Belimumab: a step forward in the treatment of systemic lupus erythematosus

Introduction: Systemic Lupus Erythematosus (SLE) is a chronic B cell-mediated autoimmune disease which can potentially involve several organs and systems. The development of SLE is associated with a complexity of genetic, hormonal and environmental factors leading to immune deregulation and production of autoantibodies. Therefore, novel therapies have focused on B cells as key effectors of SLE pathogenesis. Belimumab is a fully humanized monoclonal antibody that antagonizes B-lymphocyte stimulator (BLyS); it is the first and the only biological drug approved for SLE in over 50 years.Areas covered: In this review we discuss the pharmacological properties of belimumab, new recommendations for its use in clinical practice and its evidence of efficacy and safety based on clinical trial and real-life data.Expert opinion: Efficacy and safety of belimumab in clinical practice have been well established. To date, it is known that early introduction of belimumab in SLE can maximize the efficacy of the drug. A number of questions are still open, such as the timing of belimumab discontinuation and its possible association with other biological drugs, which need to be assessed in future studies.

Fetal Toxicity of Immunosuppressive Drugs in Pregnancy

Women affected by autoimmune diseases, organ transplantation, or neoplasia need to continue immunosuppressive treatment during pregnancy. In this setting, not only a careful planning of pregnancy, but also the choice of drugs is critical to preventing maternal complications and minimizing the fetal risks. Some immunosuppressive drugs are teratogenic and should be replaced even before the pregnancy, while other drugs need to be managed with caution to prevent fetal risks, including miscarriage, intrauterine growth restriction, prematurity, and low birth weight. In particular, the increasing use of biologic agents raises the question of their compatibility with reproduction. In this review we present data on the indication and safety in pregnancy of the most frequently used immunosuppressive drugs.

Pharmacological Approach to Managing Childhood-Onset Systemic Lupus Erythematosus During Conception, Pregnancy and Breastfeeding

Pediatric patients often have poor pregnancy outcomes. Systemic lupus erythematosus predominantly impacts women in their second to fourth decade of life, with childhood-onset disease being particularly aggressive. Reproductive issues are an important clinical consideration for pediatric patients with systemic lupus erythematosus (SLE), as maintaining good disease control and planning a pregnancy are important for maternal and fetal outcomes. In this clinical review, we will consider the safety of medications in managing childhood-onset SLE during conception, pregnancy, and breastfeeding. The developing fetus is at highest risk for teratogenicity from maternal medications during the period of critical organogenesis, which occurs between the first 3-8 weeks following conception. Medications known to be teratogenic, leading to a specific pattern of malformations, include mycophenolic acid, methotrexate, and cyclophosphamide. These should be discontinued prior to a planned pregnancy or as soon as pregnancy is suspected. Hydroxychloroquine is safe and should be continued throughout pregnancy and breastfeeding in those without contraindications to it. Azathioprine and calcineurin inhibitors are felt to be compatible with pregnancy in usual doses and may be used prior to and throughout pregnancy and lactation. Non-fluorinated corticosteroids including methylprednisolone and prednisone are inactivated by the placenta and can be used if needed for maternal indication during gestation. Addition of aspirin may be considered around the 12th week of gestation for prevention of pre-eclampsia. Illustrative cases are presented that demonstrate management of adolescents with childhood-onset SLE through conception, pregnancy, and breastfeeding.

Use of synthetic and biologic DMARDs during pregnancy

Introduction: Since most of the autoimmune diseases (AID) affect mostly women in their fertile years, and fertility is in general preserved, the use of disease-modifying antirheumatic drugs (DMARDs) during conception, pregnancy, and lactation has been a matter of concern in the treatment of women affected by AID. Areas covered: We performed a comprehensive review of the latest and most relevant research papers published in the field and discussed different aspects related to the use of synthetic and biologic DMARDs and immunosuppressants in the preconceptional period, during pregnancy and lactation in AID patients, both in males and females. Expert commentary: Active AID impose an increased risk for adverse maternal and fetal outcomes, such as preeclampsia, miscarriage, intrauterine growth restriction, prematurity, low birth weight, and stillbirth. Family planning with proper contraception and shared decision-making on the ideal time to conceive with treatment adjustment must be a rule. One of the main challenges when counseling and/or adjusting treatment of patients that are planning a pregnancy is to provide a medication that is at the same time efficacious and safe at the conceptional period and to developing the fetus.

The use of biologics and small molecules in pregnant patients with rheumatic diseases

INTRODUCTION

Biological agents have radically changed the prognosis of rheumatic patients. Current evidence demonstrates that tight disease control during pregnancy is mandatory to minimize adverse outcome risk. As the new therapeutic tools are pivotal to maintain appropriate disease activity, it is timely to review available evidence about the safety of biologics and small molecules in pregnancy. Areas covered: A comprehensive literature review has been performed, reporting available data about the passage into breast milk, rate of pregnancy loss and fetal malformations, and long-term complications due to in utero exposure to biological agents and small molecules. Expert commentary: Data about the safety of agents against tumor necrosis factor in pregnancy are reassuring. Even rituximab, tocilizumab, belimumab, ustekinumab, secukinumab, and abatacept have not been associated with an increased rate of fetal abnormalities or adverse pregnancy outcome. Experience with small molecules is too small to draw any conclusion. Even if further data are warranted to define the possible long-term effects of in utero biologic exposure on the infant immune system development, it is reasonable to speculate that in the next future the use of biologics during pregnancy will continue to expand, at least when maternal benefit justifies the potential risk to the fetus.

Are naïve T cells and class-switched memory (IgD- CD27+) B cells not essential for establishment and maintenance of pregnancy? Insights from a case of common variable immunodeficiency with pregnancy

The disruption of adaptive immune response has adverse effects on the establishment and maintenance of pregnancy. The adaptive immune system is regulated by several types of immune cells. However, there is limited information about cell hierarchy in the adaptive immune response to the establishment and maintenance of pregnancy in women. The assessment of the outcome of pregnancy in primary immunodeficiency diseases could help in understanding the cell hierarchy in the adaptive immune system during pregnancy. Common variable immunodeficiency (CVID) is a heterogeneous adaptive immune system disorder characterized by primary hypogammaglobulinemia. A few studies have previously reported the assessment of the T and B cell subpopulations in CVID patients. However, an assessment of the subpopulations of T and B cells and the outcome of pregnancy in women with CVID has not been reported till date. Most CVID patients show a general decrease in the expression of CD27 in B cells. The assessment of pregnancy and the subpopulations of T and B cells in CVID women with severe reduction in the naïve T and switched B cells could help understand whether these cells are essential for the establishment and maintenance of pregnancy in women.

Subcutaneous and intravenous belimumab in the treatment of systemic lupus erythematosus: a review of data on subcutaneous and intravenous administration

INTRODUCTION

Loss of B cell tolerance is a hallmark feature of the pathogenesis of Systemic Lupus Erythematosus (SLE). Recent advances in B cell therapy have focused on targeted therapy aimed at inhibiting B cell activation and reducing B cell survival. Belimumab, a human monoclonal antibody against B cell activating factor (BAFF) was licensed in 2011 for the treatment of SLE. Areas covered: We review the data on the intravenous and subcutaneous formulations of belimumab in the management of patients with SLE. BLISS-52 and BLISS-76 demonstrated the efficacy of intravenous belimumab (10mg/kg) as an add-on therapy in SLE patients with active disease. A recent phase III trial of intravenous belimumab reported similar results in North East Asian patients. Subcutaneous belimumab (200mg/weekly) has demonstrated similar efficacy, safety and tolerability and was approved by the FDA in 2017 for the treatment of active autoantibody positive SLE patients receiving standard therapy. Expert commentary: Belimumab is generally safe and well tolerated. The most common clinical manifestations of SLE in the clinical trials were arthritis, mucocutaneous disease and serositis. Patients with severe lupus nephritis and central nervous system disease were excluded from these clinical trials.

The use of biologics in pregnant patients with rheumatic disease

INTRODUCTION

An increasing number of female patients with autoimmune diseases are treated with biologic drugs. Concerns in regard to safety of biologics during pregnancy arise in patients who have not completed their families. Areas covered: A review of the literature dealing with child outcomes of pregnancies exposed to biologics shows that TNF inhibitors (TNFi) are the best studied in regard to human pregnancy. In studies comparing exposed pregnancies to disease-matched controls no increased risk of spontaneous abortion, low birth weight, prematurity or congenital malformations has been observed. For rituximab, tocilizumab, anakinra, belimumab and ustekinumab no prospective, controlled studies are available, and firm conclusions about their safety during pregnancy cannot be drawn. Expert commentary: TNFi appear fairly safe when given in early pregnancy. For biologics other than TNFi prospective, controlled studies on outcomes after early and late pregnancy exposure are urgently needed. Possible effects of TNFi and all other biologics on children's immune function, infection rate and vaccination responses are either limited or absent and need to be extended. Development of laboratory tests to measure concentrations of biologics routinely in children exposed in utero would facilitate decisions in regard to the time point of vaccination with live vaccines.

Clinical Pharmacokinetics and Pharmacodynamics of Biologic Therapeutics for Treatment of Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is a multifactorial autoimmune disease with potentially severe clinical manifestation that mainly affects women of child-bearing age. Patients who do not respond to standard-of-care therapies, such as corticosteroids and immunosuppressants, require biologic therapeutics that specifically target a single or multiple SLE pathogenesis pathways. This review summarizes the clinical pharmacokinetic and pharmacodynamic characteristics of biologic agents that are approved, used off-label, or in the active pipeline of drug development for SLE patients. Depending on the type of target, the interacting biologics may exhibit linear (non-specific) or non-linear (target-mediated) disposition profiles, with terminal half-lives varying from approximately 1 week to 1 month. Biologics given by subcutaneous administration, which offers dosing flexibility over intravenous administration, demonstrated a relatively slow absorption with a time to maximum concentration of approximately 1 day to 2 weeks and a variable bioavailability of 30-82 %. The population pharmacokinetics of monoclonal antibodies were best described by a two-compartment model with central clearance and steady-state volume of distribution ranging from 0.176 to 0.215 L/day and 3.60-5.29 L, respectively. The between-subject variability in pharmacokinetic parameters were moderate (20-79 %) and could be partially explained by body size. The development of linked pharmacokinetic-pharmacodynamic models incorporating SLE disease biomarkers are an attractive strategy for use in dosing regimen simulation and optimization. The relationship between efficacy/adverse events and biologic concentration should be evaluated to improve clinical trial outcomes, especially for biologics in the advanced phase of drug development. New strategies, such as model-based precision dosing dashboards, could be utilized to incorporate information collected from therapeutic drug monitoring into pharmacokinetic/pharmacodynamic models to enable individualized dosing in real time.

Scientific and Regulatory Policy Committee Points to Consider Review: Inclusion of Reproductive and Pathology End Points for Assessment of Reproductive and Developmental Toxicity in Pharmaceutical Drug Development

Standard components of nonclinical toxicity testing for novel pharmaceuticals include clinical and anatomic pathology, as well as separate evaluation of effects on reproduction and development to inform clinical development and labeling. General study designs in regulatory guidances do not specifically mandate use of pathology or reproductive end points across all study types; thus, inclusion and use of these end points are variable. The Scientific and Regulatory Policy Committee of the Society of Toxicologic Pathology (STP) formed a Working Group to assess the current guidelines and practices on the use of reproductive, anatomic pathology, and clinical pathology end points in general, reproductive, and developmental toxicology studies. The Working Group constructed a survey sent to pathologists and reproductive toxicologists, and responses from participating organizations were collected through the STP for evaluation by the Working Group. The regulatory context, relevant survey results, and collective experience of the Working Group are discussed and provide the basis of each assessment by study type. Overall, the current practice of including specific end points on a case-by-case basis is considered appropriate. Points to consider are summarized for inclusion of reproductive end points in general toxicity studies and for the informed use of pathology end points in reproductive and developmental toxicity studies.

Efficacy, pharmacokinetic and pharmacodynamic profile of belimumab for systemic lupus erythematosus

INTRODUCTION

Systemic lupus erythematosus (SLE) is a severe autoimmune disease and a sizeable proportion of patients remain refractory to currently available immunosuppressive agents. The burden of uncontrolled disease is significant as disease flare and persistent inflammation lead to long-term damage accrual and increased morbidity. Belimumab , a humanized monoclonal antibody that inhibits B-lymphocyte stimulator (BLyS), is the first drug to be approved by the US FDA for the treatment of SLE in 50 years.

AREAS COVERED

In this review, we provide an overview of novel therapeutic agents under development for the treatment of SLE, a description of the pharmacodynamic and pharmacokinetic properties of belimumab, evidence of efficacy of belimumab as demonstrated in clinical trials, safety and tolerability data and a summary of ongoing clinical trials of belimumab in SLE. This information was amassed following a comprehensive MEDLINE and Cochrane library search. Ongoing clinical trial information was obtained from ClinicalTrials.gov.

EXPERT OPINION

Two, large Phase III trials have demonstrated the clinical efficacy of belimumab in musculoskeletal, mucocutaneous, haematologic and constitutional features of SLE. Patients with severe disease manifestations such as lupus nephritis and CNS disease were excluded from these trials and hence the role of belimumab in the overall management of SLE has yet to be established. Studies in lupus nephritis are ongoing.

An Enhanced Pre- and Postnatal Development Study in Cynomolgus Monkeys with Tabalumab: A Human IgG4 Monoclonal Antibody

Tabalumab, a human IgG4 monoclonal antibody (mAb) with neutralizing activity against both soluble and membrane B-cell activating factor (BAFF), has been under development for the treatment of autoimmune diseases. The purpose of this study was to determine the potential adverse effects of maternal tabalumab exposure on pregnancy, parturition, and lactation of the mothers and on the growth, viability, and development of the offspring through postnatal day (PND) 204. Tabalumab was administered by subcutaneous injection to presumed pregnant cynomolgus monkeys (16-19 per group) every 2 weeks from gestation day (GD) 20 to 22 until parturition at doses of 0, 0.3, or 30 mg/kg. Evaluations in mothers and infants included clinical signs, body weight, toxicokinetics, blood lymphocyte phenotyping, T-cell-dependent antibody response (infants only), antitherapeutic antibody (ATA), organ weights (infants only), and gross and microscopic histopathology. Infants were also examined for external and visceral morphologic and neurobehavioral development. There were no adverse tabalumab-related effects on maternal or infant endpoints. An expected pharmacological decrease in peripheral blood B-lymphocytes occurred in adults and infants; however, B-cell recovery was evident by PND154 in adults and infants at 0.3 mg/kg and by PND204 in infants at 30 mg/kg. At 30 mg/kg, a reduced IgM antibody response to T-cell-dependent antigen keyhole limpet hemocyanin (KLH) was observed following primary immunization. Following secondary KLH immunization, all infants in both dose groups mounted anti-KLH IgM and IgG antibody responses similar to control. Placental and mammary transfer of tabalumab was demonstrated. In conclusion, the no-observed-adverse-effect level for maternal and developmental toxicity was 30 mg/kg, the highest dose tested. Exposures at 30 mg/kg provide a margin of safety of 16× the anticipated clinical exposure.

Safety issues of biologics in pregnant patients with rheumatic diseases

The safety of biologic agents during pregnancy is still being investigated. Tumor necrosis factor α (TNF-α) inhibitors are the only well-studied biological drugs in pregnancy; they do not appear to be teratogenic but increase the risk of infection after birth when given in late pregnancy. The long-term effects in exposed children are, at present, unknown. An increased risk of infection is a concern for all biologics and the risk increases further should combination with glucocorticoids be necessary. Experiences with rituximab, abatacept, anakinra, tocilizumab, and belimumab in pregnancy are limited. These drugs should be avoided during pregnancy or used only when no other option is available for treatment of serious maternal disease.

Optimized nonclinical safety assessment strategies supporting clinical development of therapeutic monoclonal antibodies targeting inflammatory diseases

An increasing number of immunomodulatory monoclonal antibodies (mAbs) and IgG Fc fusion proteins are either approved or in early-to-late stage clinical trials for the treatment of chronic inflammatory conditions, autoimmune diseases and organ transplant rejection. The exquisite specificity of mAbs, in combination with their multi-functional properties, high potency, long half-life (permitting intermittent dosing and prolonged pharamcological effects), and general lack of off-target toxicity makes them ideal therapeutics. Dosing with mAbs for these severe and debilitating but often non life-threatening diseases is usually prolonged, for several months or years, and not only affects adults, including sensitive populations such as woman of child-bearing potential (WoCBP) and the elderly, but also children. Immunosuppression is usually a therapeutic goal of these mAbs and when administered to patients whose treatment program often involves other immunosuppressive therapies, there is an inherent risk for frank immunosuppression and reduced host defence which when prolonged increases the risk of infection and cancer. In addition when mAbs interact with the immune system they can induce other adverse immune-mediated drug reactions such as infusion reactions, cytokine release syndrome, anaphylaxis, immune-complex-mediated pathology and autoimmunity. An overview of the nonclinical safety assessment and risk mitigation strategies utilized to characterize these immunomodulatory mAbs and Fc fusion proteins to support first-in human (FIH) studies and futher clinical development in inflammatory disease indications is provided. Specific emphasis is placed on the design of studies to qualify animal species for toxicology studies, early studies to investigate safety and define PK/PD relationships, FIH-enabling and chronic toxicology studies, immunotoxicity, developmental, reproductive and juvenile toxicity studies and studies to determine the potential for immunosuppression and reduced host defence against infection and cancer. Nonclinical strategies to facilitate clinical and market entry in the most efficient timeframe are presented.

Reproductive toxicity of denosumab in cynomolgus monkeys

Denosumab is a monoclonal antibody that inhibits bone resorption by targeting RANKL, an essential mediator of osteoclast formation, function, and survival. Reproductive toxicity of denosumab was assessed in cynomolgus monkeys in an embryofetal development study (dosing GD20-50) and a pre-postnatal toxicity study (dosing GD20-parturition). In the embryofetal toxicity study, denosumab did not elicit maternal toxicity, fetal harm or teratogenicity. In the pre-postnatal toxicity study, there were increased stillbirths, and one maternal death due to dystocia. There was no effect on maternal mammary gland histomorphology, lactation, or fetal growth. In infants exposed in utero, there was increased postnatal mortality, decreased body weight gain, and decreased growth/development. Denosumab-related effects in infants were present in bones and lymph nodes. There was full recovery at 6 months of age from most bone-related changes observed earlier postpartum. The effects observed in mothers and infants were consistent with the pharmacological action of denosumab.

To B or not to B cells-mediate a healthy start to life

Maternal immune responses during pregnancy are critical in programming the future health of a newborn. The maternal immune system is required to accommodate fetal immune tolerance as well as to provide a protective defence against infections for the immunocompromised mother and her baby during gestation and lactation. Natural immunity and antibody production by maternal B cells play a significant role in providing such immunoprotection. However, aberrations in the B cell compartment as a consequence of maternal autoimmunity can pose serious risks to both the mother and her baby. Despite their potential implication in shaping pregnancy outcomes, the role of B cells in human pregnancy has been poorly studied. This review focuses on the role of B cells and the implications of B cell depletion therapy in pregnancy. It highlights the evidence of an association between aberrant B cell compartment and obstetric conditions. It also alludes to the potential mechanisms that amplify these B cell aberrances and thereby contribute to exacerbation of some maternal autoimmune conditions and poor neonatal outcomes. Clinical and experimental evidence suggests strongly that maternal autoantibodies contribute directly to the pathologies of obstetric and neonatal conditions that have significant implications for the lifelong health of a newborn. The evidence for clinical benefit and safety of B cell depletion therapies in pregnancy is reviewed, and an argument is mounted for further clinical evaluation of B cell-targeted therapies in high-risk pregnancy, with an emphasis on improving neonatal outcomes and prevention of neonatal conditions such as congenital heart block and fetal/neonatal alloimmune thrombocytopenia.

Generation of gene-engineered chimeric DNA molecules for specific therapy of autoimmune diseases

Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by the development of self-reactive B and T cells and autoantibody production. In particular, double-stranded DNA-specific B cells play an important role in lupus progression, and their selective elimination is a reasonable approach for effective therapy of SLE. DNA-based vaccines aim at the induction of immune response against the vector-encoded antigen. Here, we are exploring, as a new DNA-based therapy of SLE, a chimeric DNA molecule encoding a DNA-mimotope peptide, and the Fv but not the immunogenic Fc fragment of an FcγRIIb-specific monoclonal antibody. This DNA construct was inserted in the expression vector pNut and used as a naked DNA vaccine in a mouse model of lupus. The chimeric DNA molecule can be expressed in eukaryotic cells and cross-links cell surface receptors on DNA-specific B cells, delivering an inhibitory intracellular signal. Intramuscular administration of the recombinant DNA molecule to lupus-prone MRL/lpr mice prevented increase in IgG anti-DNA antibodies and was associated with a low degree of proteinuria, modulation of cytokine profile, and suppression of lupus nephritis.

Belimumab: review of use in systemic lupus erythematosus

BACKGROUND

Belimumab, a monoclonal antibody that inhibits B-lymphocyte stimulating protein, was the first biologic agent approved for, and the first drug approved in 55 years for, the treatment of systemic lupus erythematosus (SLE) by the US Food and Drug Administration (FDA).

OBJECTIVE

This article reviews the current research on belimumab and provides recommendations on its use in the treatment of SLE.

METHODS

The Cochrane Library, EBSCO, IPA, MEDLINE, and SCOPUS were searched for research published from January 2000 to November 2011, using the search terms belimumab, Benlysta, and Lympho-Stat B. Selection criteria included peer-reviewed original research articles on the pharmacology, pharmacokinetic properties, drug interactions, and clinical efficacy and tolerability of belimumab in the treatment of SLE. Abstracts from the annual meetings of major rheumatology medical organizations and societies were searched and reviewed for new content. Additional information on belimumab was obtained from the manufacturer, from the FDA, and from other sources. MEDLINE was also used to select clinical studies and therapeutic guidelines on SLE therapy.

RESULTS

The literature search identified 1 Phase II and 2 Phase III studies that compared belimumab (1, 4, and 10 mg/kg/dose IV on days 0, 14, and 28; then every 28 days) to placebo in patients with active SLE on concurrent therapies. Patients with active lupus nephritis or neuropsychiatric lupus were excluded. In a Phase II, 52-week study, 24-week mean Safety of Estrogens in Lupus Erythematosus National Assessment-Systemic Lupus Erythematosus Disease Activity Index (SELENA-SLEDAI) scores were decreased by 19.5% with belimumab versus 17.2% with placebo (P = NS). Median time to first flare was 67 days with belimumab versus 83 days with placebo (P = NS). In seropositive patients, 52-week mean SELENA-SLEDAI scores were decreased by 28.8% with belimumab versus 14.2% with placebo (P < 0.05), and physician's global assessment scores were improved by 32.7% with belimumab versus 10.7% with placebo (P < 0.05). Two Phase III studies were performed in seropositive SLE patients. In a Phase III, 52-week study, the rates of response (a reduction of ≥4 points on the SLE Response Index [SRI]) at week 52 were 51% and 58% with belimumab 1 and 10 mg/kg/dose, respectively, versus 44% with placebo (both, P < 0.05). In a Phase III, 76-week study, the rates of response, as measured using SRI, at week 52 were 42.8% and 46.5% with belimumab 1 and 10 mg/kg/dose versus 35.3% with placebo (P = NS and P < 0.001); at 76 weeks, response rates were 42.1% and 41.4% with belimumab 1 and 10 mg/kg/dose versus 33.8% with placebo (P < 0.05 and P = NS). The tolerability data from these studies did not suggest any overall differences between belimumab and placebo.

CONCLUSIONS

Based on the findings from the present review, belimumab appears to be efficacious and generally well-tolerated and in the treatment of SLE other than lupus nephritis or neuropsychiatric lupus. Additional clinical and economics studies are needed to determine the most appropriate place for belimumab in the treatment of SLE.

Belimumab

Each month, subscribers to The Formulary Monograph Service receive 5 to 6 well-documented monographs on drugs that are newly released or are in late phase 3 trials. The monographs are targeted to Pharmacy & Therapeutics Committees. Subscribers also receive monthly 1-page summary monographs on agents that are useful for agendas and pharmacy/nursing in-services. A comprehensive target drug utilization evaluation/medication use evaluation (DUE/MUE) is also provided each month. With a subscription, the monographs are sent in print and are also available on-line. Monographs can be customized to meet the needs of a facility. Subscribers to The Formulary Monograph Service also receive access to a pharmacy bulletin board, The Formulary Information Exchange (The F.I.X.). All topics pertinent to clinical and hospital pharmacy are discussed on The F.I.X.

Through the cooperation of The Formulary, Hospital Pharmacy publishes selected reviews in this column. For more information about The Formulary Monograph Service or The F.I.X., call The Formulary at 800-322-4349. The July 2011 monograph topics are on linagliptin, peginterferon alfa-2b, abiraterone acetate, vandetanib, and ibuprofen/famotidine. The DUE/MUE is on linagliptin.

Targeting BLyS in rheumatic disease: the sometimes-bumpy road from bench to bedside

PURPOSE OF REVIEW

BLyS family ligands and receptors are key players in the selection and survival of most mature B lymphocytes. The fundamental role of BLyS in transitional B cell selection, coupled with the relative BLyS-independence of memory B cells and plasma cells, suggests that BLyS may be a useful therapeutic target in strategies directed against preimmune B cell pools. Several agents that target BLyS are in clinical trials now, and we summarize recent results here, with a focus on systemic lupus erythematosus (SLE).

RECENT FINDINGS

Belimumab, a human neutralizing anti-BLyS monoclonal antibody, has delivered moderate but positive results in two separate phase III clinical trials for SLE, and was recently recommended for approval by an FDA advisory panel. Additional agents targeting BLyS or other members of this cytokine receptor family are also being tested in clinical trials.

SUMMARY

Together, these trials should yield novel therapies for a debilitating and often intractable illness and offer insights that in turn should foster subsequent generations of personalized, targeted therapies for rheumatic diseases.

Developmental Toxicity Testing of Biopharmaceuticals in Nonhuman Primates

Developmental toxicity studies for pharmaceutical safety testing are designed to evaluate potential adverse effects of drug treatment on pregnancy and on the developing embryo/fetus. Biopharmaceuticals present specific challenges for developmental toxicity testing because the pharmacology of these molecules, which are frequently human-specific proteins, is often restricted to humans and nonhuman primates (NHPs). For those species-restricted molecules, the only option for the evaluation of potential effects on development of the human biopharmaceutical is to use NHPs. This article reviews each of the stages of development in cynomolgus macaques (the most frequently used NHP) and the potential exposure of the embryo, fetus, and infant following administration of a biopharmaceutical during pregnancy and lactation. Because the purpose of the NHP developmental studies is to identify potential human risks, a comparison between macaque and human development and potential exposure has been made when possible. Understanding the potential exposure of the conceptus relative to critical periods in development is essential to designing a scientifically based study that adequately addresses human risks. Some options for NHP study designs, including the option of combining end points into a single study, and the pros and cons of each of the study options have been reviewed. Developmental studies for biopharmaceuticals in NHPs need to be optimally designed on a case-by-case basis taking into consideration the pharmacology of the molecule, the type of molecule (antibody or non-antibody), the potential exposure relative to the development of potential target organs, the clinical use, and the ethical considerations associated with the use of NHPs.