Review of embryo-fetal developmental toxicity studies performed for pharmaceuticals approved by FDA in 2016 and 2017

pyHeart4Fish: Chamber-specific heart phenotype quantification of zebrafish in high-content screens

Cardiovascular diseases (CVDs) are the leading cause of death. Of CVDs, congenital heart diseases are the most common congenital defects, with a prevalence of 1 in 100 live births. Despite the widespread knowledge that prenatal and postnatal drug exposure can lead to congenital abnormalities, the developmental toxicity of many FDA-approved drugs is rarely investigated. Therefore, to improve our understanding of drug side effects, we performed a high-content drug screen of 1,280 compounds using zebrafish as a model for cardiovascular analyses. Zebrafish are a well-established model for CVDs and developmental toxicity. However, flexible open-access tools to quantify cardiac phenotypes are lacking. Here, we provide pyHeart4Fish, a novel Python-based, platform-independent tool with a graphical user interface for automated quantification of cardiac chamber-specific parameters, such as heart rate (HR), contractility, arrhythmia score, and conduction score. In our study, about 10.5% of the tested drugs significantly affected HR at a concentration of 20 µM in zebrafish embryos at 2 days post-fertilization. Further, we provide insights into the effects of 13 compounds on the developing embryo, including the teratogenic effects of the steroid pregnenolone. In addition, analysis with pyHeart4Fish revealed multiple contractility defects induced by seven compounds. We also found implications for arrhythmias, such as atrioventricular block caused by chloropyramine HCl, as well as (R)-duloxetine HCl-induced atrial flutter. Taken together, our study presents a novel open-access tool for heart analysis and new data on potentially cardiotoxic compounds.

Manzamine-A Alters In Vitro Calvarial Osteoblast Function

Manzamine-A is a marine-derived alkaloid which has anti-viral and anti-proliferative properties and is currently being investigated for its efficacy in the treatment of certain viruses (malaria, herpes, HIV-1) and cancers (breast, cervical, colorectal). Manzamine-A has been found to exert effects via modulation of SIX1 gene expression, a gene critical to craniofacial development via the WNT, NOTCH, and PI3K/AKT pathways. To date little work has focused on Manzamine-A and how its use may affect bone. We hypothesize that Manzamine-A, through SIX1, alters bone cell activity. Here, we assessed the effects of Manzamine-A on cells that are responsible for the generation of bone, pre-osteoblasts and osteoblasts. PCR, qrtPCR, MTS cell viability, Caspase 3/7, and functional assays were used to test the effects of Manzamine-A on these cells. Our data suggests Six1 is highly expressed in osteoblasts and their progenitors. Further, osteoblast progenitors and osteoblasts exhibit great sensitivity to Manzamine-A treatment exhibited by a significant decrease in cell viability, increase in cellular apoptosis, and decrease in alkaline phosphatase activity. In silico binding experiment showed that manzamine A potential as an inhibitor of cell proliferation and survival proteins, i.e., Iκb, JAK2, AKT, PKC, FAK, and Bcl-2. Overall, our data suggests Manzamine-A may have great effects on bone health overall and may disrupt skeletal development, homeostasis, and repair.

Review of embryo-fetal developmental toxicity studies performed for pharmaceuticals approved by FDA in 2020 and 2021

103 novel drugs were approved by the FDA in 2020-2021. Embryofetal development (EFD) studies were conducted for 76% of these approvals. For the majority of drugs, EFD studies were conducted in rats and rabbits. Both species were equally sensitive to developmental toxicity, but the rabbit was slightly more sensitive to maternal toxicity at the same systemic exposure level. Nonetheless, 68% of drugs showed more than a 2-fold difference in the low adverse effect level for developmental toxicity between the rat and rabbit. Previous reviews in this series compiled information on EFD studies for all small molecule pharmaceuticals approved since 2014 and for all therapeutic monoclonal antibodies approved to date. The use of non-human primates for the developmental toxicity testing of biopharmaceuticals has fallen over recent years (22% of biologics license applications (BLAs) for 2020-2021, compared with 62% for 2002-2015), with more biopharmaceuticals now tested in rodents (37% of BLAs for 2020-2021). While the Pregnancy and Lactation Labeling Rule (PLLR), adopted in 2014, has brought consistency to the presentation of EFD data in drug labels, prescribers complain that the pregnancy section of current drug labels is neither concise nor clear. The FDA has pledged to address the concerns of clinicians in a future revision of the PLLR rule. The recommendations on risk assessment in the recently revised ICHS5(R3) guideline could be incorporated into the PLLR rule to remove extraneous nonclinical details from the label with the aim of facilitating rapid understanding by the practitioner.

When pharmaceutical drugs become environmental pollutants: Potential neural effects and underlying mechanisms

Pharmaceutical drugs have become consumer products, with a daily use for some of them. The volume of production and consumption of drugs is such that they have become environmental pollutants. Their transfer to wastewater through urine, feces or rinsing in case of skin use, associated with partial elimination by wastewater treatment plants generalize pollution in the hydrosphere, including drinking water, sediments, soils, the food chain and plants. Here, we review the potential effects of environmental exposure to three classes of pharmaceutical drugs, i.e. antibiotics, antidepressants and non-steroidal anti-inflammatory drugs, on neurodevelopment. Experimental studies analyzing their underlying modes of action including those related to endocrine disruption, and molecular mechanisms including epigenetic modifications are presented. In addition, the contribution of brain imaging to the assessment of adverse effects of these three classes of pharmaceuticals is approached.

Non-human Primate Models to Investigate Mechanisms of Infection-Associated Fetal and Pediatric Injury, Teratogenesis and Stillbirth

A wide array of pathogens has the potential to injure the fetus and induce teratogenesis, the process by which mutations in fetal somatic cells lead to congenital malformations. Rubella virus was the first infectious disease to be linked to congenital malformations due to an infection in pregnancy, which can include congenital cataracts, microcephaly, hearing impairment and congenital heart disease. Currently, human cytomegalovirus (HCMV) is the leading infectious cause of congenital malformations globally, affecting 1 in every 200 infants. However, our knowledge of teratogenic viruses and pathogens is far from complete. New emerging infectious diseases may induce teratogenesis, similar to Zika virus (ZIKV) that caused a global pandemic in 2016-2017; thousands of neonates were born with congenital microcephaly due to ZIKV exposure in utero, which also included a spectrum of injuries to the brain, eyes and spinal cord. In addition to congenital anomalies, permanent injury to fetal and neonatal organs, preterm birth, stillbirth and spontaneous abortion are known consequences of a broader group of infectious diseases including group B streptococcus (GBS), Listeria monocytogenes, Influenza A virus (IAV), and Human Immunodeficiency Virus (HIV). Animal models are crucial for determining the mechanism of how these various infectious diseases induce teratogenesis or organ injury, as well as testing novel therapeutics for fetal or neonatal protection. Other mammalian models differ in many respects from human pregnancy including placentation, labor physiology, reproductive tract anatomy, timeline of fetal development and reproductive toxicology. In contrast, non-human primates (NHP) most closely resemble human pregnancy and exhibit key similarities that make them ideal for research to discover the mechanisms of injury and for testing vaccines and therapeutics to prevent teratogenesis, fetal and neonatal injury and adverse pregnancy outcomes (e.g., stillbirth or spontaneous abortion). In this review, we emphasize key contributions of the NHP model pre-clinical research for ZIKV, HCMV, HIV, IAV, L. monocytogenes, Ureaplasma species, and GBS. This work represents the foundation for development and testing of preventative and therapeutic strategies to inhibit infectious injury of human fetuses and neonates.

Concordance of 3 alternative teratogenicity assays with results from corresponding in vivo embryo-fetal development studies: Final report from the International Consortium for Innovation and Quality in Pharmaceutical Development (IQ) DruSafe working group 2

An IQ DruSafe working group evaluated the concordance of 3 alternative teratogenicity assays (rat whole embryo culture, rWEC; zebrafish embryo culture, ZEC; and murine embryonic stem cells, mESC) with findings from rat or rabbit embryo-fetal development (EFD) studies. Data for 90 individual compounds from 9 companies were entered into a database. In vivo findings were deemed positive if malformations or embryo-fetal lethality were reported in either species. Each company used their own criteria for deciding whether the alternative assay predicted the in vivo findings. Standard concordance parameters were calculated, positive and negative predictive values (PPV and NPV) were adjusted for the aggregate portfolio prevalence of positive compounds (established by a survey of participating companies), and positive and negative likelihood ratios (LR+ and iLR-) were calculated. Of the 3 assays, only rWEC data were robustly predictive, particularly for negative predictions (NPVadj = 92%). However, both LR+ (4.92) and iLR- (4.72) were statistically significant for the rWEC assay. When analyzed separately for rats, the NPVadj and iLR-values for the rWEC assay increased to 96% and 9.75, respectively. These data suggest that a negative rWEC outcome could defer or replace a rat EFD study in certain regulatory settings.

Evaluation of Drug Labels Following the 2015 Pregnancy and Lactation Labeling Rule

IMPORTANCE

The US Food and Drug Administration (FDA) Pregnancy and Lactation Labeling Rule (PLLR), implemented in 2015, includes information on pregnancy, lactation, and women and men with reproductive potential.

OBJECTIVES

To identify the drugs that have adhered to the new PLLR format; to shed light on the continued need for implementation of pregnancy, lactation, and reproduction into clinical studies; and to evaluate how many new therapeutic products have human and animal data specific to pregnancy and lactation.

DESIGN, SETTING, AND PARTICIPANTS

This cross-sectional study of 290 new therapeutic drugs reviewed labeling data for newly FDA-approved therapeutic products from January 2010 to December 2019. Therapeutic products submitted on or after June 30, 2015, were required to be in PLLR format; those approved from June 30, 2007, to June 29, 2015, had until June 30, 2019, to be in PLLR format. Approval data and subsequent labeling revision were evaluated for pregnancy and lactation data (human and animal), pregnancy registry, black-box warnings, and inclusion of PLLR labeling format.

EXPOSURES

Date of new drug approval by FDA.

MAIN OUTCOMES AND MEASURES

Compliance with PLLR; presence of animal or human data; presence of pregnancy registries; and presence of information regarding female and male reproductive potential.

RESULTS

A total of 290 new molecular entities or therapeutic products were approved by the FDA between 2010 and 2019 in 19 categories. Black-box warnings occurred in 89 drugs (30.7%; 95% CI, 25.4%-36.3%), with 3 (3.4%; 95% CI, 0.7%-9.5%) involving pregnancy. All products submitted after June 30, 2015, were in PLLR format; however, of the 138 submitted between 2010 and that date, 45 (32.6%; 95% CI, 24.9%-41.1%) were not in PLLR format by June 30, 2019. During the 10 years of data analyzed, significantly more were in PLLR format (P for trend < .001). Most approved therapeutic products have pregnancy data derived from animal studies (260 products; 89.7%; 95% CI, 85.6%-92.9%) but only 31 (10.7%; 95% CI, 7.4%-14.8%) derived data from human studies. Only 148 therapeutic products (51.0%; 95% CI, 45.1%-56.9%) had any data associated with lactation, 143 (49.3%; 95% CI, 43.4%-55.2%) originating from animal studies and 8 (2.8%; 95% CI, 1.2%-5.4%) from human studies.

CONCLUSIONS AND RELEVANCE

The results of this study show that with the implementation of PLLR in the last decade, new therapeutic products were in compliance with the new rules; however, more than one-third of labels remain out of PLLR compliance. Human data on pregnancy and lactation are available in less than 20% of new product labeling.

Review of embryo-fetal developmental toxicity studies performed for pharmaceuticals approved by FDA in 2018 and 2019

Details of embryo-fetal development (EFD) studies were compiled for all FDA drug approvals in 2018-19. EFD studies were performed for 82 % of approvals (84 % of small molecules and 70 % of biopharmaceuticals). Rats and rabbits were used for 84 % of small molecule (SM) drugs for which EFD studies were submitted. There was at least a 2-fold difference in sensitivity between the rat and the rabbit relative to the human exposure for the majority of drugs (62 %, small molecules and biopharmaceuticals combined) tested in both species. On average, however, the rat and rabbit were equally sensitive to developmental toxicity. Over the last 2 years, the use of non-human primates (NHP) for the developmental toxicity testing of biopharmaceuticals has fallen (26 % of biologics license applications), with many more biopharmaceuticals now tested in rodents (44 % of BLAs). EFD studies were not required for oncology drugs when the mode of action was associated with known developmental risk. One-third of SM non-oncology drugs and two-thirds of SM oncology drugs induced dysmorphogenesis in at least one species. The newly revised ICH S5(R3) guideline will bring about changes to the design of future EFD studies, particularly with respect to high dose selection. The revised guideline will also influence the interpretation of the findings in EFD studies (e.g. fetal morphological variations) and risk assessment.

Enhanced normograms and pregnancy outcome analysis in nonhuman primate developmental toxicity studies

The incidence of spontaneous pregnancy/infant losses is highly variable in long-tailed macaques (cynomolgus monkey), making it potentially difficult to ascertain test item-related effects in developmental toxicity studies. Therefore, pregnancy normograms had been developed by Jarvis et al. [1] to aid in the distinction of normal (e.g. test facility background) versus non-normal pregnancy outcomes. These normograms were mostly derived from embryo-fetal development studies and from PPND studies with a postnatal phase limited to seven days. However, the enhanced pre- and postnatal developmental (ePPND) study paradigm has essentially replaced these former study types. This work aims at providing enhanced normograms (e-normograms) in the context of regulatory ePPND studies. Survival functions for the prenatal phase (286 control pregnancies) and the postnatal phase (222 live infants) were estimated using the Kaplan-Meier estimator. Normograms were generated from survival curves and pseudo-study simulations. Data were available from two test facilities with comparable EU-compliant animal husbandry. Pregnancy duration/outcome as well as survival functions did not differ significantly between test facilities indicating that this husbandry system yields comparable developmental observations across different test facilities, at least in this NHP species. These novel e-normograms were developed for pregnant long-tailed macaques and provide an extended postnatal period up to three months, a new concept of separate normograms for the prenatal and the postnatal period, specific information on the perinatal phase events, a prediction of expected number of live infants for group size management, and the option to evaluate effects on pregnancy duration through distinction of live births and infant losses.

The moral imperative to approve pregnant women's participation in randomized clinical trials for pregnancy and newborn complications

BACKGROUND

There is longstanding consensus on the need to include pregnant women in research. The goal of clinical research is to find highly regulated, carefully controlled, morally responsible ways to generate evidence about how to effectively and safely prevent illness or treat sick people. This manuscripts present a conceptual analysis of the ethicality of clinical trials in 3 scenarios: where the pregnant is involved in clinical trials as a participant during pregnancy for data that addresses pregnancy complications, where the pregnant woman consents to clinical trial participation for an unborn baby that has complications, to generate data on complications at this stage of life, and where the mother may consent for participation of their newborn child in clinical trials.

METHODS

Conceptual analysis.

FINDINGS

Investigators often choose to exclude pregnant women and newborns from research, even where there is possibility for them to benefit from the study intervention. Objections include vulnerability of pregnant women, altered pharmacokinetics and risk of adverse effects, with a need to balance potential maternal and fetal risks and benefits of research participation. While the objections may be valid, not performing research magnifies what should be a carefully controlled risk during research, pushing this risk into the clinical setting, and subsequently posing a challenge to clinicians who are faced with making treatment decisions for pregnant patients with limited evidence of efficacy and safety. The potential benefits of fair inclusion in clinical trials outweigh the potential risks.

CONCLUSION

Research involving pregnant women is necessary to provide women with effective treatment during pregnancy, to promote fetal safety (such as by avoiding the clinical use of drugs that may be harmful to the developing fetus), and to reduce avoidable harm from suboptimal care (such as from underdosing) and to provide pregnant women, their fetuses and newborns (with access to potential benefits of research participation).