reproductive toxicology | Leaders in Pharmaceutical Business Intelligence (LPBI) Group

Posts Tagged ‘reproductive toxicology’

Mimicking vaginal cells and microbiome interactions on chip microfluidic culture

Posted in Automated Cell Processing, Bio Instrumentation in Experimental Life Sciences Research, Biological Engineering, Biological Networks, Biotechnology, Cell Level, Clinical & Translational, Clinical Diagnostics, Diagnostics and Lab Tests, Medical Device Therapies for Altzheimer’s Disease, Microbiology, MicroEngineering Cell-Tissue & Systems, Microfuidics, Mobile Healthcare, Organ-on-a-Chip, Patient-centered Medicine, Personal Health Applications: Tech Innovations serves HealhCare, Personalized and Precision Medicine & Genomic Research, Population Health Management, Population Health Management, Genetics & Pharmaceutical, Reproductive Andrology, Embryology, Genomic Endocrinology, Preimplantation Genetic Diagnosis and Reproductive Genomics, Reproductive Biology & Bio Instrumentation, Signaling, Tissue Engineering, Women Health, tagged artificial vagina, reproduction, reproductive health, reproductive medicine, reproductive research, reproductive toxicology on February 14, 2023| Leave a Comment »

Mimicking vaginal cells and microbiome interactions on chip microfluidic culture

Reporter and Curator: Dr. Sudipta Saha, Ph.D.

Scientists at Harvard University’s Wyss Institute for Biologically Inspired Engineering have developed the world’s first “vagina-on-a-chip,” which uses living cells and bacteria to mimic the microbial environment of the human vagina. It could help to test drugs against bacterial vaginosis, a common microbial imbalance that makes millions of people more susceptible to sexually transmitted diseases and puts them at risk of preterm delivery when pregnant. Vaginal health is difficult to study in a laboratory setting partly because laboratory animals have “totally different microbiomes” than humans. To address this, scientists have created an unique chip, which is an inch-long, rectangular polymer case containing live human vaginal tissue from a donor and a flow of estrogen-carrying material to simulate vaginal mucus.

The organs-on-a-chip mimic real bodily function, making it easier to study diseases and test drugs. Previous examples include models of the lungs and the intestines. In this case, the tissue acts like that of a real vagina in some important ways. It even responds to changes in estrogen by adjusting the expression of certain genes. And it can grow a humanlike microbiome dominated by “good” or “bad” bacteria. The researchers have demonstrated that Lactobacilli growing on the chip’s tissue help to maintain a low pH by producing lactic acid. Conversely, if the researchers introduce Gardnerella, the chip develops a higher pH, cell damage and increased inflammation: classic bacterial vaginosis signs. So, the chip can demonstrate how a healthy / unhealthy microbiome affects the vagina.

The next step is personalization or subject specific culture from individuals. The chip is a real leap forward, it has the prospect of testing how typical antibiotic treatments against bacterial vaginosis affect the different bacterial strains. Critics of organ-on-a-chip technology often raise the point that it models organs in isolation from the rest of the body. There are limitations such as many researchers are interested in vaginal microbiome changes that occur during pregnancy because of the link between bacterial vaginosis and labor complications. Although the chip’s tissue responds to estrogen, but it does not fully mimic pregnancy without feedback loops from other organs. The researchers are already working on connecting the vagina chip to a cervix chip, which could better represent the larger reproductive system.

All these information indicate that the human vagina chip offers a new model to study host-vaginal microbiome interactions in both optimal and non-optimal states, as well as providing a human relevant preclinical model for development and testing of reproductive therapeutics, including live bio-therapeutics products for bacterial vaginosis. This microfluidic human vagina chip that enables flow through an open epithelial lumen also offers a unique advantage for studies on the effect of cervicovaginal mucus on vaginal health as clinical mucus samples or commercially available mucins can be flowed through this channel. The role of resident and circulating immune cells in host-microbiome interactions also can be explored by incorporating these cells into the vagina chip in the future, as this has been successfully done in various other organ chip models.

References:

https://www.scientificamerican.com/article/first-vagina-on-a-chip-will-help-researchers-test-drugs/

https://www.webmd.com/infertility-and-reproduction/news/20230209/scientists-create-vagina-on-chip-what-to-know

https://www.livescience.com/vagina-on-a-chip

https://link.springer.com/article/10.1186/s40168-022-01400-1

https://www.nature.com/articles/s41585-022-00717-8

Read Full Post »

FDA Guidelines For Developmental and Reproductive Toxicology (DART) Studies for Small Molecules

Posted in Bio Instrumentation in Experimental Life Sciences Research, Biomarkers & Medical Diagnostics, BioSimilars, Chemical Biology and its relations to Metabolic Disease, Disease Biology, Small Molecules in Development of Therapeutic Drugs, FDA Regulatory Affairs, Health Economics and Outcomes Research, Health Law & Patient Safety, Pharmaceutical Industry Competitive Intelligence, Population Health Management, Genetics & Pharmaceutical, Regulated Clinical Trials: Design, Methods, Components and IRB related issues, Reproductive Biology & Bio Instrumentation, Uncategorized, tagged Biology, Biosimilar, Clinical trial, development, Drug development, FDA, Food and Drug Administration, health, medicine, Regulatory, reproductive toxicology, small molecule, toxicology, United States on November 20, 2012| 4 Comments »

FDA Guidelines For Developmental and Reproductive Toxicology (DART) Studies for Small Molecules. Author-Writer: Stephen J. Williams, Ph.D.

This posting is a follow-up on the Report on the Fall Mid-Atlantic Society of Toxicology Meeting “Reproductive Toxicology of Biologics: Challenges and Considerations post and gives a brief synopsis of the current state of FDA regulatory guidelines with respect to DART studies on small molecule (non-biological based) therapeutics. The following is adapted from the book Principles and Methods of Toxicology by Dr. A Wallace Hayes (1) and is an excellent reference on reproductive toxicology and testing methods.

Chemical insult occurs to the human reproductive system at a multitude of stages in development and the life cycle, leading to the extensive testing which must be performed to diligently the reproductive and development toxicity of a chemical/drug. Abnormalities and toxic manifestations in the offspring may result from insult to the adult reproductive (either female or male) and neuroendocrine systems, as well as damage to the embryo resulting in embryolethality, fetus at any period during organogenesis, juvenile development or, in the case of certain antibody therapies, immune system development. The latter, toxic insult to the developing immune system could possibly be manifested as either an immune defect in the newborn or, later in life, as tolerance to said therapy. It is estimated that exposure to the pregnant woman, of either environmental contaminants or drug, is significant. It is estimated that a mother may be taking an average of 8-9 different drug preparations, mostly over the counter preparations such as antacids, vitamin preparations, cathartics etc. with the maximal drug intake occurring between 24 and 36 weeks of gestation.

Toxic insult to the developing embryo is dependent on

Fetal development stage during drug/chemical exposure
Maternal/placental xenobiotic metabolism
Pharmacokinetic parameters affecting bioavailability and fetal/maternal drug binding

The following table shows the dependency of developmental stage to teratogenicity: adapted from J. Manson, H. Zenick, and R.D. Costlow from Principles and Methods of Toxicology.

Developmental Stage	Major Susceptibility
Preimplantation	Embryolethality
Organogenesis	Births defects; embryolethality
Fetal	Growth retardation, fetal death, functional deficits
Neonatal	Growth retardation, nervous system alterations, immune and endocrine systems

It is not generally accepted that there is a dose dependency of teratogenesis however most teratogens have specific mechanisms of action and teratogenic effects occur at much lower doses than result in maternal toxicity. However, the developmental toxicity may be manifested later in life, including as reproductive toxicity affecting adult fertility and familial generations.

FDA Guidelines for DART Studies on Non-Biologics (Small Molecule Therapeutics)

The basic design for DART studies incorporate the aforementioned principles of tetralogy:

developmental stage of fetal exposure
parental effects on reproduction and development
toxicity may be manifested over multiple generations including fertility rates

Therefore two designs are generally used for DART studies

exposure across several generations
exposure during one generation

FDA requires one control group and two treatment groups, and evaluation of at least two species. However, most studies will use two rodent and one nonrodent species.

Multigenerational Design

Multigenerational DART studies are conducted for compounds likely to concentrate in the body following long-term exposure. Examples of types of compounds include pesticides and food additives.

Figure 1. General Design of a Multigenerational DART study. Weanlings (30-30 days of age) from the parental generation are treated for a period up to 60 days. At 100-120 days of parental generation, animals are mated. F_x = filial_x .

Three Segment, Single Generation Tests

The single generation design is more suitable for DART studies on drugs, as most therapeutic would be taken over short periods (during pregnancy) and have relatively short half-lives in the body. FDA guidelines separate these studies in three phases:

I. Phase I: evaluation of fertility and general reproductive performance

II. Phase II: assessment of teratogenicity and embryotoxicity

III. Phase III: peri- and postnatal evaluations.

All figures are adapted from Principles and Methods of Toxicology.(1)

FDA guidelines Guidance for Industry Reproductive and Developmental Toxicities —Integrating Study Results to Assess Concerns can be found at: http://www.fda.gov/downloads/Drugs/GuidanceComplianceRegulatoryInformation/Guidances/ucm079240.pdf

FDA Guideline for reproductive toxicity testing for small molecule therapeutics can be found at:

http://www.fda.gov/downloads/Drugs/GuidanceComplianceRegulatoryInformation/Guidances/ucm074950.pdf

1. Hayes, A. W. (1986) Principles and Methods of Toxicology, Raven Press, New York

Other research papers on Pharmaceutical Intelligence and Reproductive Biology, Bio Insrumentation, Endocrinology Genetics were published on this Scientific Web site as follows

Non-small Cell Lung Cancer drugs – where does the Future lie?

Reboot evidence-based medicine and reconsider the randomized, placebo-controlled clinical trial

Every sperm is sacred: Sequencing DNA from individual cells vs “humans as a whole.”

Leptin and Puberty

Gene Trap Mutagenesis in Reproductive Research

Genes involved in Male Fertility and Sperm-egg Binding

Hope for Male Contraception: A small molecule that inhibits a protein important for chromatin organization can cause reversible sterility in male mice

Pregnancy with a Leptin-Receptor Mutation

The contribution of comparative genomic hybridization in reproductive medicine

Sperm collide and crawl the walls in chaotic journey to the ovum

Impact of evolutionary selection on functional regions: The imprint of evolutionary selection on ENCODE regulatory elements is manifested between species and within human populations

Biosimilars: CMC Issues and Regulatory Requirements

Biosimilars: Intellectual Property Creation and Protection by Pioneer and by Biosimilar Manufacturers

Assisted Reproductive Technology Cycles and Cumulative Birth Rates

Innovations in Bio instrumentation in Reproductive Clinical and Male Fertility Labs in the US

Increased risks of obesity and cancer, Decreased risk of type 2 diabetes: The role of Tumor-suppressor phosphatase and tensin homologue (PTEN)

Guidelines for the welfare and use of animals in cancer research

Every sperm is sacred: Sequencing DNA from individual cells vs “humans as a whole.”

Read Full Post »

Report on the Fall Mid-Atlantic Society of Toxicology Meeting “Reproductive Toxicology of Biologics: Challenges and Considerations:

Posted in Bio Instrumentation in Experimental Life Sciences Research, BioSimilars, Chemical Biology and its relations to Metabolic Disease, Disease Biology, Small Molecules in Development of Therapeutic Drugs, FDA Regulatory Affairs, Health Economics and Outcomes Research, Health Law & Patient Safety, Human Immune System in Health and in Disease, Pharmaceutical Analytics, Pharmaceutical Industry Competitive Intelligence, Uncategorized, tagged Aviva Lev-Ari, Biology, biosimilars, Clinical trial, Drug development, FDA, Food and Drug Administration, health, medicine, Pfizer, pharmaceutical drugs, Regulatory, reproductive research, reproductive toxicology, science, toxicity, toxicology on November 7, 2012| 8 Comments »

Report on the Fall Mid-Atlantic Society of Toxicology Meeting “Reproductive Toxicology of Biologics: Challenges and Considerations. Author, Reporter: Stephen J. Williams, Ph.D.

The fall 2012 Meeting of the Mid-Atlantic Society of Toxicology (MASOT) focused on the challenges and solutions in developing proper Development and Reproductive Toxicology (DART) studies with regards to the newer classes of bio-therapeutics such as vaccines, antibody-based therapies, and viral-based therapies. The full meeting and MASOT links can be found at http://www.masot.org. The overall synopsis of the meeting talks agreed, that although the general aim and design of DART studies for biological are very similar to DART studies for small molecule therapeutics, it is more necessary to take into consideration the pharmacodynamics, pharmacokinetic differences between biologics and small molecules. In addition it is imperative to use pharmacologically-relevant species, such as non-rodent (guinea pig and non-human primate). The meeting was highlighted by the keynote speaker, Dr. A. Wallace Hayes, renowned board-certified toxicologist, committee and expert panel member for National Academy of Sciences, NIEHS, EPA and Department of Defense, and editor of well-known textbooks including Principles and Methods of Toxicology. Dr. Hayes discussed a timeline of milestones in the field of toxicology.

The following are the meeting talk abstracts as well as notes for each presenter.

What’s So Different About DART Assessment of Biologics? Christopher Bowman Ph.D., DABT (Pfizer, Inc.)

Abstract: The aim of developmental and reproductive toxicity (DART) safety assessment of a biologic is no different from that of a small molecule. Both cases consist of evaluating the potential for maternal toxicity, pre- and postnatal development toxicity (including juvenile toxicity) and effects of fertility (reproduction). The differences lie in the in the product attributes of a specific biologic, the pharmacological response, the potential for undesirable toxicities and how these product attributes influence and are influenced by the biology. Thus the primary challenge for developing a DART strategy for a biologic are derived from the complexities of these biomolecules and how that dictates a case-by-case strategy for appropriately evaluating the potential for developmental and reproductive toxicity. Most protein biologics have very limited potential for off-target toxicities, but this is not necessarily the case for other modalities such as anti-sense oligonucleotides and antibody-drug-conjugates. In these cases, off-target toxicities can be a major feature of the DART safety assessment. The most noticeable difference in DART assessment of biologics is the need to conduct these studies in pharmacologically relevant species and how that can influence the overall nonclinical strategy (including DART). This has led to increased use of non-human primates as a model system and led to optimizations of this model for this purpose and revisions to international guidelines.

Notes: Dr. Bowman emphasized the need to understand the type of biological you are testing and to both devise DART studies based on this information, additional endpoint you may want, as well as carefully choosing the correct species most relevant to the biologic. He highlighted general differences between small molecules versus a biologic with respect to their pharmacology. These differences are summarized in the Table below:

	Small Molecule	Biologic-based therapy
Species specificity	Low	High
Route of administration	Usually oral	Parental
ADME (PK, bio-distribution etc.)	Wide distribution	Low distribution

He noted that clinical trials for biologics rarely include reproductive toxicity so the preclinical DART study is of utmost importance. He also emphasized that currently, the FDA requires two species for DART testing of small molecule therapies (usually one rodent and one non-rodent). However this is not possible with many biologics as species is to be taken in consideration when designing a meaningful DART study. Study designs can be like most DART studies but want to have a steady exposure during fetal organogenesis, use high doses (10 times the clinical dose) to achieve maximal pharmacology, confirm exposure to fetus and to F1 generation, and determine embryolethality. Some biologics like interferon and insulin-growth factor receptor (IGFR) antagonists are fetal abortifactants. In fact Lucentis (Ranibizumab) and Macugen (Pegaptanib) were approved with no or little DART studies, however these drugs showed reproductive toxicity, resulting in warning concerning pregnancy on the label. Also important is the effect on the immune system and reproductive system of offspring, as well as the pharmacodynamics profile in the offspring.

Species Selection for Reproductive and Developmental Toxicity Testing of Biologics; Elise M. Lewis, Ph.D. (Charles River Preclinical Services)

Abstract: Regulatory guidelines for developmental and reproductive toxicology studies require selection of “relevant” animal models as determined by kinetic, pharmacological, and preceding toxicological data. Rats, mice, and rabbits are the preferred animal models for these studies based on historical experience and well-established procedures and study protocols. However, due to species specificity and immunogenicity issues, developmental and reproductive toxicology testing for biologics is limited to a pharmacologically relevant animal model as described in the ICH s6 guideline.

Notes: Dr. Lewis notes that DART studies in guinea pigs and hamsters represent a cost effective alternative to large animal models as well as the benefit of shorter duration and ability to assess mating behavior. She also notes that reproductive toxicology of vaccines should be done in an animal model that can elicit an immune-response to the vaccine, especially to determine any maternal-fetal interaction. For example, a vaccine may be directed to a maternal protein which when suppressed, may negatively impact the developing fetus. However it is important to remember that guinea pigs can spontaneously abort so it is good to have proper control arms of a substantial size in order to statistically determine the impact of those spontaneous abortions.

Placental Transfer of an Adnectin Protein During Organogenesis in Guinea Pigs Using a Radiolabeled Methodology; Lakshmi Sivaraman, Ph.D. (Bristol-Myers Squibb)

Abstract: Knowledge regarding the placental transfer of large molecular weight therapeutics is important to support the enrollment of women of childbearing potential in clinical trials. There is limited information in the scientific literature that reports the extent to which the conceptus is exposed to these large molecules during organogenesis. Placental transfer of large therapeutics has been difficult to quantify, due to limited blood volumes that can be obtained from the embryo, as well as insufficient assay sensitivity. Thus, it is possible that embryos are exposed to pharmacologically active concentrations after maternal drug exposure. We have adopted a radiolabeled approach to quantitate embryo-fetal exposure of a novel protein therapeutic platform (adnectins). Adnectins are fibronectin-based proteins containing domains engineered to bind to targets of therapeutic interests.

Notes: Adnectins molecular weight is typically less than monoclonal antibodies and while IgG is not transferred in great quantity past the placental barrier there have been studies in human indicating maternal-fetal transfer of monoclonal antibodies. This is particularly important for two reasons: the monoclonal interacts with a target important in development, or the fetal immune system could be augmented. Their work will be published in Drug Metabolism and Disposition. In general Dr. Siveraman engineered a radiolabel on adnectin and used different detection methods to quantify the fetal exposure to a single maternal dose. Dr. Siverman was able to detect radiolabel in the fetus however it is not clear whether this is a significant amount.

Reproductive Toxicity Testing for Biological Products in Nonhuman Primates: Evolution and Current Perspectives: Gary J. Chellman, Ph.D., DABT (Charles River Preclinical Services)

Notes: Dr. Chellman gave a review of the current trends being driven by regulatory agencies with regard to nonhuman primate DART studies of biopharmaceuticals. He noted that an advantage using nonhuman primates were the close physiologic resemblance to humans and because a large animal could monitor pregnancy over time using ultrasound technology. In general, Dr. Chellman spoke about new study designs which not only reduce the number of animals required but also significantly reduce costs. For example, a DART study which cost upward of $750,000 now can be done for as little as $350,000. Dr. Kary Thompson of Bristol Myers Squibb then gave a talk about use of these new enhanced designs to determine reproductive toxicity issues with ipilimumab (Yervoy).

Other research papers on Pharmaceutical Intelligence and Reproductive Biology, Bio Insrumentation, Endocrinology Genetics were published on this Scientific Web site as follows