Antje Fuchs

Physiology and Endocrinology of the Ovarian Cycle in Macaques

Macaques provide excellent models for preclinical testing and safety assessment of female reproductive toxicants. Currently, cynomolgus monkeys are the predominant species for (reproductive) toxicity testing. Marmosets and rhesus monkeys are being used occasionally. The authors provide a brief review on physiology and endocrinology of the cynomolgus monkey ovarian cycle, practical guidance on assessment and monitoring of ovarian cyclicity, and new data on effects of social housing on ovarian cyclicity in toxicological studies. In macaques, cycle monitoring is achieved using daily vaginal smears for menstruation combined with cycle-timed frequent sampling for steroid and peptide hormone analysis. Owing to requirements of frequent and timed blood sampling, it is not recommended to incorporate these special evaluations into a general toxicity study design. Marmosets lack external signs of ovarian cyclicity, and cycle monitoring is done by regular determinations of progesterone. Cynomolgus and marmoset monkeys do not exhibit seasonal variations in ovarian activity, whereas such annual rhythm is pronounced in rhesus monkeys. Studies on pair- and group-housed cynomolgus monkeys revealed transient alterations in the duration and endocrinology of the ovarian cycle followed by return to normal cyclicity after approximately six months. This effect is avoided if the animals had contact with each other prior to mingling. These experiments also demonstrated that synchronization of ovarian cycles did not occur. Competing Interests: This article was sponsored by Covance Inc. and Schering-Plough. Gerhard F. Weinbauer, Marc Niehofg, Michael Niehaus, Shiela Srivasav, and Antje Fuchs are employed by Covance Inc. Eric Van Esch is employed by Schering-Plough. No other competing interests were declared.

Postnatal development in cynomolgus monkeys following prenatal exposure to natalizumab, an α4 integrin inhibitor

BACKGROUND Natalizumab is a humanized monoclonal IgG4 antibody to human alpha4 integrin that blocks the interaction of alpha4beta1 and alpha4beta7 integrins with their ligands, including fibronectin, vascular cell adhesion molecule-1, and mucosal addressin cellular adhesion molecule-1. Because alpha4 integrins and their ligands are widely involved in mammalian development, lymphopoeisis, and hematopoiesis, natalizumab may interfere with these processes. METHODS The effects of prenatal exposure to natalizumab on postnatal development were assessed in cynomolgus monkeys at doses of 0 and 30 mg/kg administered intravenously every other day from gestational day (GD) 20 to 70 or GD 20 to term. Infants were delivered by natural birth and evaluated for general health, survival, development, and immunological structure and function at 12 or 18 months. RESULTS An increase in abortions was seen in the first cohort of natalizumab-treated dams (39.3 vs. 7.1% in the controls) but not in the second cohort (33.3, 37.5%). Infants in the term treatment group had elevated lymphocyte ( approximately 150%) and nucleated red blood cell counts ( approximately 400%), consistent with the pharmacological effect of natalizumab, and reductions in platelet counts ( approximately 28%), which were reversible following clearance of natalizumab. No anemia was observed. Infants in the term treatment group had significantly increased spleen weights at 12 months but not at 18 months. All other experimental observations in infants from natalizumab-treated dams were comparable with those of controls. CONCLUSION Natalizumab had no adverse effects on the general health, survival, development, or immunological structure and function of infants born to dams treated with natalizumab during pregnancy.

The enhanced pre‐ and postnatal study for nonhuman primates: Update and perspectives

The enhanced pre- and postnatal (ePPND) study design has been developed in response to new scientific knowledge and subsequent guideline changes, that is, ICH M3(R2) and ICH S6(R1). The design changes were basically driven by the experiences obtained during preclinical development of biopharmaceuticals. The ePPND concept typically does not apply to pharmaceuticals. In essence, the ePPND design is a PPND study in which key elements of an embryofetal development (EFD) study are being investigated in newborns and infants rather than in the fetus. The current relevant nonhuman primate model is the cynomolgus monkey. The ICH S6(R1) has reached step 4 during June 2011 and provides detailed recommendations on various parameters and the conduct of an ePPND study. By the time this article is written, it appears that for monoclonal antibodies, the ePPND study is the preferred approach although ICH S6(R1) also leaves options for modified EFD and PPND study concepts. Our data also demonstrate that social housing is feasible for developmental toxicity studies in the cynomolgus monkey model.

The Enhanced Pre- and Postnatal Development Study for Monoclonal Antibodies

The enhanced pre- and postnatal (ePPND) study design has been developed in response to new scientific knowledge and subsequent guideline changes [ICH M3(R2) and ICH S6(R1)]. The changes in study design were basically driven by the experiences obtained during preclinical development of biopharmaceuticals. The standard ePPND concept does not apply to conventional small molecule pharmaceuticals. In essence, the ePPND design is a pre- and postnatal development (PPND) study in which key elements of an embryo-fetal development study are investigated in newborns and infants rather than in the fetus. The cynomolgus monkey is the current relevant nonhuman primate model. The ICH S6(R1) guideline reached step 5 in June 2011 and provides detailed recommendations on various parameters and the conduct of an ePPND study. This chapter provides working guidance for monitoring menstrual cycles to generate pregnant animals, ultrasound monitoring of pregnancy, morphometric measurements of fetuses and newborns, in vivo skeletal examination, various protocols for evaluation of infants (e.g., neurobehavioral assessment, learning and memory test, grip strength, immune system evaluation) and a comprehensive list of additional infant evaluation parameters for the cynomolgus monkey.

Continuing harmonization of terminology and innovations for methodologies in developmental toxicology: Report of the 8th Berlin Workshop on Developmental Toxicity, 14-16 May 2014.

This article is a report of the 8th Berlin Workshop on Developmental Toxicity held in May 2014. The main aim of the workshop was the continuing harmonization of terminology and innovations for methodologies used in the assessment of embryo- and fetotoxic findings. The following main topics were discussed: harmonized categorization of external, skeletal, visceral and materno-fetal findings into malformations, variations and grey zone anomalies, aspects of developmental anomalies in humans and laboratory animals, and innovations for new methodologies in developmental toxicology. The application of Version 2 terminology in the DevTox database was considered as a useful improvement in the categorization of developmental anomalies. Participants concluded that initiation of a project for comparative assessments of developmental anomalies in humans and laboratory animals could support regulatory risk assessment and university-based training. Improvement of new methodological approaches for alternatives to animal testing should be triggered for a better understanding of developmental outcomes.

Embryo fetal development studies in nonhuman primates.

Embryo fetal development (EFD) studies in nonhuman primates are frequently conducted in macaques with Macaca fascicularis (cynomolgus monkey, long-tailed macaque, crab-eating macaque) being the most accepted model. EFD studies are also feasible in the marmoset. Due to recent guideline changes (ICH M3(R2) and S6(R1)), EFD studies are largely confined to conventional pharmaceutical compounds rather than biopharmaceuticals. This chapter describes basic study designs and provides working protocols for collecting, processing, and staining fetuses, including collection of amniotic fluid and umbilical cord blood. The chapter also covers the examination and terminology for external, visceral, and skeletal examinations of fetuses. The species covered in this chapter are cynomolgus monkey (long-tailed macaque) and marmoset monkey.

Effects of SA237, a humanized anti-interleukin-6 receptor monoclonal antibody, on pre- and postnatal development in cynomolgus monkey

BACKGROUND SA237 is a humanized anti-interleukin-6 receptor (IL-6R) monoclonal antibody in which the constant and variable regions have been engineered for a longer plasma half-life. According to literature, blocking of IL-6 related functions could have an influence on pregnancy sustainment, development of the immune system, and brain growth. METHODS SA237 effects on dams, embryo-fetal development, parturition and postnatal development were investigated in an enhanced pre- and postnatal development study, in which SA237 was subcutaneously administered to pregnant cynomolgus monkeys at dose levels of 2 or 50 mg/kg once weekly from gestation day 20 until parturition. Infant development, including immune function and learning ability tests, was comprehensively assessed at multiple examinations until approximately 10 months after birth. RESULTS SA237 plasma concentrations were almost equivalent between dams and their infants and dropped throughout the postnatal period, pharmacologically relevant exposure was maintained for 147 days after birth at 50 mg/kg. Because the binding of SA237 to IL-6R inhibited IL-6R-mediated clearance of IL-6, serum IL-6 increased in dams and infants. However, there were no SA237-related adverse effects on dams, embryos, fetuses, or infants. SA237 pharmacological effects contributed to the suppression of plasma cell differentiation and antibody production by inhibiting IL-6 signaling, and T cell-dependent antibody reaction was minimally suppressed in infants, but physiological immunoglobulin class switching and general antibody production against a T cell-dependent antigen were maintained. CONCLUSION The exposure to SA237 did not adversely affect dams, embryo-fetal development, parturition, and postnatal development, including immune function and neuronal development. Birth Defects Research 109:843-856, 2017.