Evaluation of the effect of rozanolixizumab on pregnancy outcomes and pre- and postnatal development in cynomolgus monkeys.

Rozanolixizumab, a humanised immunoglobulin (Ig) G4 monoclonal antibody that selectively inhibits binding of IgG to the neonatal Fc receptor (FcRn), was evaluated in an embryo-foetal enhanced pre- and postnatal development (ePPND) study. Pregnant female cynomolgus monkeys (19 per group) received subcutaneous rozanolixizumab 50mg/kg or 150mg/kg or vehicle every 3 days from gestation day 20 until delivery. The proportion of pregnancy losses was 15.

Enhanced Prenatal and Postnatal Development Study in Marmoset Monkeys Following Administration of Felzartamab.

Felzartamab is a recombinant fully human immunoglobulin G1 anti-CD38 monoclonal antibody under clinical investigation for immune-mediated diseases. In support of felzartamab clinical development, toxicology studies were conducted in marmoset monkeys, which was the most relevant species based on CD38 binding affinity, pharmacologic activity, and target expression. The felzartamab toxicology program included an enhanced prenatal and postnatal development (ePPND) study to identify potential reproductive and postnatal development risks.

Deep Learning-Based Spermatogenic Staging in Tissue Sections of Cynomolgus Macaque Testes.

The indirect assessment of adverse effects on fertility in cynomolgus monkeys requires that tissue sections of the testis be microscopically evaluated with awareness of the stage of spermatogenesis that a particular cross-section of a seminiferous tubule is in. This difficult and subjective task could very much benefit from automation. Using digital whole slide images (WSIs) from tissue sections of testis, we have developed a deep learning model that can annotate the stage of each tubule with high sensitivity, precision, and accuracy.

Intravitreal RTH258 (brolucizumab) demonstrates no effect on pregnancy, parturition, embryofetal or postnatal development in cynomolgus monkeys.

RTH258 (brolucizumab) is a humanized single chain antibody fragment, the smallest functional unit of an antibody designed to target vascular endothelial growth factor in angiogenic retinal disease. To further understand the safe use of RTH258, this study assessed the potential impact of intravitreal RTH258 on pre- and postnatal development in the offspring of cynomolgus monkeys following administration to the mother. Three groups of 16 pregnant females were included: a low dose group (RTH258 3 mg/50 µl [60 mg/ml]), a high dose group (RTH258 6 mg/50 µl [120 mg/ml]), and a control group.

Effect of ofatumumab on pregnancy, parturition, and lactation in cynomolgus monkeys.

Knowledge of the impacts of the anti-CD20 monoclonal antibody ofatumumab on the developing immune system is limited. This study examined the effects of intravenous ofatumumab on pregnancy, parturition, and lactation, and on pre- and postnatal survival and development in cynomolgus monkeys, an established model for developmental toxicity assessment. Pregnant cynomolgus monkeys (n = 42) were randomized to receive vehicle only (control group; n = 14), low-dose ofatumumab (n = 14), or high-dose ofatumumab (n = 14).

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.

Group size experiences with enhanced pre- and postnatal development studies in the long-tailed macaque ().

Enhanced pre- and postnatal development (ePPND) studies have become the default developmental toxicity test for biopharmaceuticals if nonhuman primates represent the relevant species. Spontaneous pregnancy losses and infant deaths can be significant in macaques such as long-tailed macaques. The International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use (ICH) guideline S6(R1) states that pregnancy outcome can be judged also by the normogram-based variability of reference data according to a publication by Jarvis et al.

Toxicologic Pathology Forum*: Opinion on Sexual Maturity and Fertility Assessment in Long-tailed Macaques ( Macaca fascicularis) in Nonclinical Safety Studies.

If nonhuman primates represent the only relevant species for nonclinical safety evaluation of biotechnology-derived products, male and female fertility effects can be assessed in repeat dose toxicity studies given that sexually mature monkeys are used. This opinion piece provides recommendations for determining sexual maturity and when/how fertility assessments should be conducted in the cynomolgus monkey. Male sexual maturity should be proven by presence of sperm in a semen sample, female sexual maturity by at least two consecutive menstrual bleedings.

Feasibility of repeated testing for learning ability in juvenile primates for pediatric safety assessment.

Assessment of learning ability in nonhuman primate (NHP) models is sometimes requested by regulatory authorities. The double choice object discrimination task using a Wisconsin General Testing Apparatus (WGTA) approach is typically being applied. In this study, the WGTA approach was performed on 66 juvenile cynomolgus monkeys aged 8-9 months in the predose phase of juvenile toxicity assessment.

Intratesticular testosterone is increased in men with Klinefelter syndrome and may not be released into the bloodstream owing to altered testicular vascularization– a preliminary report.

Klinefelter syndrome (KS, 47,XXY) is associated with low serum testosterone (T), long thought to arise from disturbed steroidogenesis in Leydig cells. However, intratesticular testosterone (ITT) concentrations were recently found to be normal in a KS mouse model(41,XXY*). So far, nothing was known about ITT concentrations in human patients with KS.

Sensitivity of male reproductive endpoints in nonhuman primate toxicity studies: a statistical power analysis.

To determine the sensitivity of male reproductive toxicity endpoints in NHPs we performed a power analysis of routine and triggered endpoints using control data from sexually mature Asian and Mauritian NHPs. The power to detect a 50% change from control was 13-30% for male reproductive organ weights, ∼30% for testicular volume, 6-66% for seminal analyses and 10-78% for male hormones. Overall, male reproductive endpoints have poor power (less than 80%) to detect a 50% change from control with a group size of 3 monkeys.

Experimental endocrine manipulation by contraceptive regimen in the male marmoset (Callithrix jacchus).

Marmosets are used as preclinical model in reproductive research. In contrast to other primates, they display short gestation times rendering this species valid for exploration of effects on fertility. However, their peculiar endocrine regulation differs from a those of macaques and humans.

Functional assessment of sexual maturity in male macaques (Macaca fascicularis).

Selection of suitable criteria for assessing sexual maturity in the male long-tailed macaque (Macaca fascicularis) has yielded conflicting results. The present retrospective work investigates whether the sole presence of sperm in the baseline semen sample unequivocally (i.e.

Testosterone-induced prostate growth is blocked by co- and preadministration of norethisterone enanthate in castrated cynomolgus monkeys.

Introduction: Prostate size and function are regulated by testosterone. However, the progesterone receptor is expressed in the primate prostate. Progestins affect the prostate by endocrine suppression, but can also act directly.

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.

Reduced expression of DNMT3B in the germ cells of patients with bilateral spermatogenic arrest does not lead to changes in the global methylation status.

DNA methylation events during spermatogenesis have important implications for gamete integrity and transmission of epigenetic information to the next generation. However, the role of DNA methyltransferases in the disorders of human spermatogenesis has not been elucidated. The aim of the present study was to evaluate the expression of DNMT3B, crucial for full germ cell methylation, in testicular germ cells of patients with spermatogenic arrest and to determine whether or not there is an association with the global methylation status.

Male 41, XXY* mice as a model for klinefelter syndrome: hyperactivation of leydig cells.

Sex chromosome imbalance in males is linked to a supernumerary X chromosome, a condition resulting in Klinefelter syndrome (KS; 47, XXY). KS patients suffer from infertility, hypergonadotropic hypogonadism, and cognitive impairments. Mechanisms of KS pathophysiology are poorly understood and require further exploration using animal models.

New horizons for in vitro spermatogenesis? An update on novel three-dimensional culture systems as tools for meiotic and post-meiotic differentiation of testicular germ cells.

Culture and differentiation of male germ cells has been performed for various purposes in the past. To date, none of the studies aimed at in vitro spermatogenesis has resulted in a sufficient number of mature gametes. Numerous studies have revealed worthy pieces of information, building up a body of information on conditions that are required to maintain and mature male germ cells in vitro.

Impaired recognition memory in male mice with a supernumerary X chromosome.

Several aberrant chromosomal constellations are known in men. Of these the karyotype XXY (Klinefelter syndrome, KS) is the most common chromosomal disorder with a prevalence of about one in 800 live-born boys. KS is associated with hypogonadism and is suspected to cause variable physical, physiological and cognitive abnormalities.

The fate of paternal mitochondria in marmoset pre-implantation embryos.

Background: Sperm-derived mitochondria are integrated into the oocyte at fertilization but seem to vanish during the early cleavage phase. The developmental potential of pre-implantation embryos seems to be closely related to their ability to induce degeneration of these mitochondria, but the mechanisms underlying their loss of function are not yet understood. This study focuses on the fate of paternal mitochondria in pre-implantation embryos.

Complete spermatogenesis in orthotopic but not in ectopic transplants of autologously grafted marmoset testicular tissue.

Testicular grafting has the potential to become a method to preserve fertility in prepubertal boys undergoing cancer treatment. The possibility of successful germ cell maturation after autologous grafting should be proven preclinically in a nonhuman primate model. Therefore, in two experiments, we analyzed the potential of autologous testicular grafting in the marmoset model.

Quantification of seminal germ cells in azoospermia: correlations with testicular histology and TESE outcome.

In the treatment of male infertility by intra-cytoplasmic injection of spermatozoa (ICSI) extracted from testicular tissue (TESE), the high incidence of negative TESE outcome calls for non-invasive prognostic methods. Literature suggests that seminal haploid germ cell detection could be one. For this purpose, a multi-parametric stringent flow cytometric method was applied to 50 TESE patients for the quantification of ejaculated germ cells.

Coculture of spermatogonia with somatic cells in a novel three-dimensional soft-agar-culture-system.

Isolation and culture of spermatogonial stem cells (SSCs) has become an approach to study the milieu and the factors controlling their expansion and differentiation. Traditional conventional cell culture does not mimic the complex situation in the seminiferous epithelium providing a basal, intraepithelial, and adluminal compartment to the developing male germ cells. SSCs are located in specific stem cell niches whose features and functional parameters are thus far poorly understood.

LHR splicing variants and gene expression in the marmoset monkey.

In the marmoset monkey, the LHR type II, lacking exon 10, is the native receptor type. We characterised the LHR splicing pattern in marmoset testes and the adrenals during puberty and in pre- and postpubertal ovaries and quantified mRNA LHR expression in the testis. We detected 11 LHR splicing variants expressed at similar levels and generated by exon skipping and/or usage of cryptic splice sites.

Chorionic gonadotropin beta-subunit gene expression in the marmoset pituitary is controlled by steroidogenic factor 1, early growth response protein 1, and pituitary homeobox factor 1.

In most mammals, the gonads are under the control of the pituitary gonadotropins LH and FSH. However, in the common marmoset monkey Callithrix jacchus, no LH is detectable in the pituitary but chorionic gonadotropin (CG) instead, normally produced in the placenta. This study investigated the mechanism of CGbeta subunit activation in the pituitary and why humans do not express CG in the pituitary.