Reproductive Toxicology Studies Research Articles

An in vitro testicular organoid model for the study of testis morphogenesis, somatic cell maturation, endocrine function, and toxicological assessment of endocrine disruptors

Male reproductive capacity has fallen considerably in recent decades; in addition, the incidence of testicular cancer has increased in many developed countries. The cause of this phenomenon is unknown, but environmental toxicants are considered a major contributing factor. To study potential reproductive toxicants, robust in vitro testis models are needed. We have recently established a porcine testis organoid system with a high resemblance to the architectures of innate testis tissue. Here, we further investigated the testis morphogenesis, cell maturation, and endocrine function of the testis organoids. We also challenged this system with abiraterone, a steroidogenic inhibitor, to validate its suitability as an in vitro platform for endocrine toxicology tests. Our results showed that the testis cells in the organoids reorganize into testis cordal structures, and the cordal relative areas increase in the organoids over time of culture. Moreover, the diameters and cell numbers per cross-section of the cordal structures increased over time. Interestingly, Sertoli cells in the organoids gradually underwent maturational changes by showing increased expression of androgen receptors, decreased expression of the anti-müllerian hormone, and formation of the blood-testis barrier. Next, we confirmed that the organoids respond to hormonal stimulation and release multiple sex hormones, including testosterone, estradiol, and progesterone. Finally, we showed that the production of testosterone and estradiol in this system can be inhibited in response to the steroidogenic inhibitor. Taken together, our organoid system provides a promising in vitro platform for male reproductive toxicology studies on testis morphogenesis, somatic cell maturation, and endocrine production.

An optimized radioimmunoassay for quantification of total serum thyroxine (T4) in fetal, neonatal, and pregnant rats

Identifying xenobiotics that interrupt the thyroid axis has significant public health implications, given that thyroid hormones are required for brain development. As such, some developmental and reproductive toxicology (DART) studies now require or recommend serum total thyroxine (T4) measurements in pregnant, lactating, and developing rats. However, serum T4 concentrations are normally low in the fetus and pup which makes quantification difficult. These challenges can be circumvented by technologies like mass spectrometry, but these approaches are expensive and not always widely available. To demonstrate the feasibility of measuring T4 using a commercially available assay, we examine technical replicates of rat serum samples measured both by liquid chromatography mass spectrometry (LC/MS/MS) and radioimmunoassay (RIA). These samples were obtained from rats on gestational day 20 (dams and fetuses) or postnatal day 5 (pups), following maternal exposure to the goitrogen propylthiouracil (0–3 ppm) to incrementally decrease T4. We show that with assay modification, it is possible to measure serum T4 using low sample volumes (25–50 μL) by an RIA, including in the GD20 fetus exposed to propylthiouracil. This proof-of-concept study demonstrates the technical feasibility of measuring serum T4 in DART studies.

Galectin-1 Used in Assisted Reproduction-Embryo Safety and Toxicology Studies.

Galectin-1 has been cited as a mediator involved in preventing early embryonic death in mammals and is implicated in maternal-fetal tolerance. Galectin-1 is also a reasonable tool to improve fertility in assisted reproduction procedures. As recommended in the ICH guidelines (S5-R2 and S6-R1) and based on bioethical concerns, we chose bovine embryos (BE) to assess in vitro embryo development as part of a larger reproductive safety and toxicology study in progress. The design considered in vitro embryo development using rHGAL-1 supplementations (in three different concentrations) of the in vitro embryo culture (IVP) media. Based on procedures for the commercial in vitro production of BE using oocytes aspirated from slaughterhouse ovaries, rHGAL-1 supplementation was performed in two experiments: In Experiment 1 on oocyte maturation, involving IVM medium supplementation, and in Experiment 2 on culture step IVC, involving supplementation with an SOF medium. IVP commercial procedures were used, with three IVP replicates per experiment, and the oocytes we distributed into four groups of treatment (one control group and three different dosages of rHGAL-1 to supplement both IVM and SOF media using 2, 20, and 40 µg·mL-1, respectively. A total of 967 (Experiment 1) and 1213 (Experiment 2) oocytes were aspirated and submitted to the IVP procedure. There was no damage to the in vitro bovine embryo growth when considering cleavage percentage (%CLE), blastocyst development (Bl, Bx, Bh, and B) at Days 7 and 8, or an amount of rHGAL-1 supplementation ≤20 µg·mL-1. The immunohistochemistry assay with D8 embryos cultivated using rHGAL-1 supplementation on the culture medium (SOF medium) demonstrated the presence of exogenous GAL-1 distributed in mass cell and trophoblastic cells, and the profile observed was dependent on exogenous supplementation, which was most evident in hatched embryos. The findings confirmed the use of a reasonable amount of rHGAL-1 for in vitro embryonic development and would make the use of rHGAL-1 in assisted reproduction in humans more reliable and safer. Even though it was not the objective of the study, we verified that supplementation with 2 µg·mL-1 significantly improved some of the evaluated parameters of embryonic development (%BlD7, %BD7, %BlD8, %BhD8, and %BD8).

An evaluation of reproductive toxicity studies and data interpretation of N-methylpyrrolidone for risk assessment: An expert panel review

An expert panel was assembled to evaluate reproductive toxicology study data and their application to health risk assessment to provide input on the data quality, interpretation, and application of data from three multi-generation reproductive toxicity studies of N-methylpyrrolidone (NMP). Panelists were engaged using a double-blinded, modified Delphi format that consisted of three rounds. Key studies were scored using the U.S. Environmental Protection Agency's (EPA) questions and general considerations to guide the evaluation of experimental animal studies for systematic review. The primary conclusions of the panel are that one of the studies (Exxon, 1991) is not a high-quality study due to several design flaws that includes: (1) exceedance of the maximum tolerable dose in the high dose group; (2) failure to adjust feed concentrations of NMP during the lactation period, resulting in NMP doses that were 2- to 3-fold higher than nominal levels; and/or (3) underlying reproductive performance problems in the strain of rats used. For these reasons, the panel recommended that this study should not be considered for quantitative risk assessment of NMP. Exclusion of this study, and its corresponding data for male fertility and female fecundity, from the quantitative risk assessment results in a change in the identification of the most sensitive endpoint. Instead, changes in rat fetal/pup body weight, an endpoint previously selected by EPA, was identified as an appropriate basis for human health risk assessment based on a consideration of the best available science and weight of scientific evidence supported by the NMP toxicity database.

Does environmental pollution affect male reproductive system in naturally exposed vertebrates? A systematic review

Due to environmental contamination, the environment constantly receives pollutants from various anthropic actions. These pollutants put ecological health at risk due to contamination and accumulation in living organisms, including wild animals and humans. Exposure can cause physiological, morphological, and behavioral changes in living beings. In this context, laboratory studies have frequently investigated how environmental contaminants affect the male reproductive system and gametes. However, few studies have examined how these contaminants affect male reproduction in naturally exposed animals. To better understand this topic, we conducted a systematic review of the effects of exposing male vertebrate animals to polluted environments on their reproductive functions. After an extensive search using the PubMed/MEDLINE, Scopus, and Web of Science databases, 39 studies met our inclusion criteria and were eligible for this review. This study showed that reproductive damages were frequent in fishes, amphibians, reptiles, birds, and mammals exposed to contaminated environments. Wild animals are exposed mainly to endocrine-disrupting compounds (EDCs), toxic metals, and radiation. Exposure to pollutants causes a reduction in androgen levels, impaired spermatogenesis, morphological damage to reproductive organs, and decreased sperm quality, leading to reduced fertility and population decline. Although several species have been studied, the number of studies is limited for some groups of vertebrates. Wildlife has proven valuable to our understanding of the potential effects of environmental contaminants on human and ecosystem health. Thus, some recommendations for future investigations are provided. This review also creates a baseline for the understanding state of the art in reproductive toxicology studies.

Effect of vinpocetine on embryonic heart rate in vitro

Vinpocetine is a readily available nutritional supplement claimed to improve memory and weight loss.However, it blocks the Ikr current essential for cardiac action potential repolarisation and Ikr inhibition can cause “torsade de pointes” arrhythmias and sudden death. Moreover, Ikr blockers have exhibited teratogenic effects in reproductive toxicology studies, leading to increased birth defects and embryonic mortality. The FDA advises against vinpocetine use in pregnant and prospective mothers based on animal studies showing dose-dependent fetal mortality in rats and rabbits, and cardiovascular malformations in surviving fetuses. However, the mechanisms responsible for vinpocetine's fetal toxicity remain unclear.The present study used rat embryo culture to evaluate vinpocetine and its major metabolite, apovincaminic acid, on embryonic heart rate, a possible causative factor behind its adverse effects. Both compounds induced embryonic bradycardia in a concentration-dependent manner, with vinpocetine proving more potent.The minimum vinpocentine concentration to induce bradycardia was 100 nM, a level unlikely to be reached in humans following typical doses. Embryonic arrhythmias were also observed at the highest concentrations.These results suggest that the FDA's cautionary statement may generate undue anxiety, although re-evaluation of teratogenicity risk associated with vinpocetine should be revisited if a link to cardiac arrhythmias in adults is established.

Reproductive and developmental toxicology studies of iminosugar UV-4

UV-4 (N‐(9‐methoxynonyl)‐1‐deoxynojirimycin) is a host-targeted antiviral agent, which targets mammalian proteins (endoplasmic reticulum glucosidases) rather than virally encoded proteins. This mechanism confers both broad-spectrum activity and low potential for generation of viral drug resistance mutations. Reproductive and developmental studies of UV-4 evaluated effects on fertility and early embryonic development in rats, embryo-fetal development in rats and rabbits, and pre- and postnatal development including maternal function in rats. All reproductive and developmental studies conducted achieved dose levels where parental toxicity (generally decreased body weight, decreased food consumption and adverse clinical signs) were observed. Toxicokinetic evaluations confirmed UV-4 crossed the placenta exposing fetal rats and rabbits in utero. Adverse findings in reproductive and developmental studies included decreases in sperm motility with histopathology correlates, visceral and skeletal malformations, changes in eye opening, air drop reflex, vaginal opening and preputial separation. The combined results of the fertility and early embryonic developmental study and pre- and postnatal study suggested that there may be an increased risk for male fertility. These effects are similar to those reported in pre-clinical studies of the structurally related drug Miglustat (N-butyl-1-deoxynojirimycin), therefore UV-4 may have risk of developmental or reproductive adverse outcomes in humans similar to existing approved agents in this drug class.

Non-clinical considerations for supporting accelerated inclusion of pregnant women in pre-licensure clinical trials with anti-HIV agents.

IntroductionTo allow the continued participation of women enrolled in pre‐licensure clinical trials who become pregnant, and to potentially enrol pregnant women in clinical trials, non‐clinical developmental and reproductive toxicology studies (DART) are essential. Generally during pharmaceutical development, DART studies are conducted late during clinical development, leading to the exclusion of pregnant women from enrolment and withdrawal of women becoming pregnant during pre‐licensure trials.DiscussionCompleting all DART studies prior to or early during the conduct of phase 3 trials (i.e. earlier than current common practice) can accelerate and facilitate the inclusion of women who become pregnant during pre‐licensure trials to remain on study drug and to potentially enrol pregnant women more rapidly. Promoting complementary strategies, such as alternative combinations of DART study designs and physiologically based pharmacokinetic modelling, could better inform drug dosing and safety in pregnancy at an earlier stage in drug development. The interpretation of the results of non‐clinical DART studies is often complex. Institutional review boards/ethics committees should have access to relevant expertise for interpretation and application of results of non‐clinical developmental and reproductive toxicity studies. Clear communication and thorough understanding of non‐clinical findings and the overall benefit–risk profile of the product are critical to review protocols and determine if women who become pregnant during a clinical trial could continue on study drug and/or to enrol pregnant women in the trial. The informed consent document should be well written so that participants can make an informed decision to stay on study drug or participate in a trial during pregnancy. Ultimately, the decision to allow women who become pregnant during pre‐licensure trials to remain on study will depend on the totality of the evidence and benefit–risk considerations.ConclusionsWe propose that industry completes non‐clinical reproductive toxicity studies prior to or early during the conduct of phase 3 trials in HIV drug development, especially for priority agents, and potentially uses alternative DART study design strategies to achieve this goal.

A comparative study of the effects of 3 testicular toxicants in cultures of seminiferous tubules of rats or of domestic cats (veterinary waste): An alternative method for reprotoxicology

In response to the EU cosmetics directive regulation and REACH legislation which encourage cell culture methods in order to reduce or replace the use of animals in toxicology studies, we settled the culture of prepubertal domestic cat seminiferous tubules in our validated BioAlter® model, usually used with prepubertal rat, called here BioAlter®-rat, by opposition to BioAlter®-cat settled here. We carried out a comparative study on the effects of 3 testicular toxicants, 1,3-dinitrobenzene at 60 μM, 2-methoxyacetic acid at 2.5 mM and carbendazim at 50 nM or 500 nM in both BioAlter®-cat and BioAlter®-rat over a 3-week culture period. Sertoli cell or each germ cell populations as well as the levels of Sertoli cell or germ cell specific mRNAs were studied. The harmful effects of the 3 toxicants on pre-meiotic, meiotic and post-meiotic cell numbers and on Sertoli or germ cell specific mRNAs were clearly observed in the two species, even if there might be some small differences in the intensity of the effects on some of the studied parameters. Hence, BioAlter®-cat might be a solution to the requirements of the EU cosmetics directive and REACH legislation for male reproductive toxicology studies.

Prioritise research on vaccines for pregnant and breastfeeding women

Prioritise research on vaccines for pregnant and breastfeeding women

Brief Synopsis: "Instruction Manual for Juvenile Clinical Pathology".

This symposium synopsis summarizes key points discussed related to clinical pathology data interpretation for reproduction and juvenile toxicology studies. In pregnant and growing animals, several changes in clinical pathology parameters linked to growth/maturation of organ and physiological functions can occur, and understanding these changes is important to enable accurate interpretation of clinical pathology data. A brief overview of the general approach to clinical pathology data analysis according to contemporary practices is provided, followed by a discussion focused specifically on reproductive and juvenile clinical pathology. In this context, the approach to recognize and differentiate changes that may be related to pregnancy and growth as opposed to those that may be related to test article effects is highlighted.

COVID-19 Vaccine in Pregnant and Lactating Women: A Review of Existing Evidence and Practice Guidelines.

Coronavirus 2019 (COVID-19) has created a global pandemic that is devastating human lives, public healthcare systems, and global economies. Multiple effective and safe COVID-19 vaccines have been developed at an unprecedented speed due to the efforts of the scientific community, and collaboration between the federal government and pharmaceutical companies. However, the continued exclusion of pregnant and lactating women from the COVID anti-viral and vaccine trials has created the paradox of a lack of empirical evidence in a high-risk population. Based on the experience of similar prior vaccines, animal developmental and reproductive toxicology studies, and preliminary findings from human studies, various healthcare professional advisory committees (Advisory Committee on Immunization Practices, American College of Obstetricians and Gynecologists, Society for Maternal-Fetal Medicine, and Academy of Breastfeeding Medicine) have issued guidance supporting COVID-19 vaccination in pregnant and lactating women. In this article, we summarize the available data on the efficacy and safety profile of COVID-19 vaccination in pregnant and lactating women, review the challenges of vaccine hesitancy, and include recommendations for healthcare providers.

Coronavirus Disease 2019 (COVID-19) Vaccines and Pregnancy: What Obstetricians Need to Know.

Coronavirus disease 2019 (COVID-19) vaccines have begun to be distributed across the United States and to be offered initially to priority groups including health care personnel and persons living in long-term care facilities. Guidance regarding whether pregnant persons should receive a COVID-19 vaccine is needed. Because pregnant persons were excluded from the initial phase 3 clinical trials of COVID-19 vaccines, limited data are available on their efficacy and safety during pregnancy. After developmental and reproductive toxicology studies are completed, some companies are expected to conduct clinical trials in pregnant persons. Until then, pregnant persons and their obstetricians will need to use available data to weigh the benefits and risks of COVID-19 vaccines. Issues to be considered when counseling pregnant persons include data from animal studies and inadvertently exposed pregnancies during vaccine clinical trials when available, potential risks to pregnancy of vaccine reactogenicity, timing of vaccination during pregnancy, evidence for safety of other vaccines during pregnancy, risk of COVID-19 complications due to pregnancy and the pregnant person's underlying conditions, and risk of exposure to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and potential for risk mitigation. The Centers for Disease Control and Prevention, the American College of Obstetricians and Gynecologists, and the Society for Maternal-Fetal Medicine have each issued guidance supportive of offering COVID-19 vaccine to pregnant persons. As additional information from clinical trials and from data collected on vaccinated pregnant persons becomes available, it will be critical for obstetricians to keep up to date with this information.

Repeated Dose Toxicity Study and Developmental and Reproductive Toxicology Studies of a Respiratory Syncytial Virus Candidate Vaccine in Rabbits and Rats.

Respiratory syncytial virus (RSV) is a leading cause of acute lower respiratory tract infections, and vaccines are needed to treat young children and older adults. One of GSK's candidate vaccines for RSV contains recombinant RSVPreF3 protein maintained in the prefusion conformation. The differences in immune function of young children and older adults potentially require different vaccine approaches. For young children, anti-RSV immunity can be afforded during the first months of life by vaccinating the pregnant mother during the third trimester with unadjuvanted RSVPreF3, which results in protection of the infant due to the transplacental passage of anti-RSV maternal antibodies. For older adults with a waning immune response, the approach is to adjuvant the RSVPreF3 vaccine with AS01 to elicit a more robust immune response.The local and systemic effects of biweekly intramuscular injections of the RSVPreF3 vaccine (unadjuvanted, adjuvanted with AS01, or coadministered with a diphtheria-tetanus-acellular pertussis vaccine) was tested in a repeated dose toxicity study in rabbits. After three intramuscular doses, the only changes observed were those commonly related to a vaccine-elicited inflammatory reaction. Subsequently, the effects of unadjuvanted RSVPreF3 vaccine on female fertility, embryo-fetal, and postnatal development of offspring were evaluated in rats and rabbits. There were no effects on pregnancy, delivery, lactation, or the pre- and postnatal development of offspring.In conclusion, the RSVPreF3 vaccine was well-tolerated locally and systemically and was not associated with any adverse effects on female reproductive function or on the pre- and postnatal growth and development of offspring.

Ethical and Regulatory Considerations of Placental Therapeutics

PurposePlacental therapeutics aim to treat placental disease; however, ethical and regulatory issues should be considered if the drug also potentially affects the fetus. Drugs that might transfer or edit genes carry a specific challenge because currently fetal gene editing and fetal gene therapy are considered unethical. MethodsThis article reviews the literature on ethical and regulatory considerations for placental therapeutics. FindingsProposals for maternal gene therapy, directed to the maternal side of the placenta, have been discussed with patients and stakeholders. No absolute ethical, legal, or regulatory barriers to this potential treatment were identified. Patients who have experienced placental disease, such as fetal growth restriction, are interested in these therapies; some would participate in first-in-human trials. Such trials need careful regulatory considerations, such as the steps required to indicate tolerability and efficacy in preclinical models and the optimal animals for reproductive toxicology studies. Ex vivo dual human placenta perfusion experiments and villous explant in vitro studies allow drugs to be tested in normal and diseased human placenta, providing short-term tolerability and toxicologic assessment. Testing drugs in nonhuman primates is an option but carries ethical and feasibility considerations. Selection of inclusion and exclusion criteria for clinical trial participants is important to ensure that the most suitable patients are exposed to a first-in-human drug. These patients will almost certainly be pregnant women with a high risk of perinatal loss and/or perinatal and maternal morbidity. Criteria should identify sufficient numbers of patients to make a trial feasible as well as a phenotype that will respond to the mechanism of action. How to dose escalate and to capture information on adverse events are also key to optimal clinical trial design. ImplicationsDeveloping placental therapeutics requires input from scientists, practitioners, and regulators and close liaison with patients to ensure that new drugs are tested as carefully as possible.

Growth of Japanese Quail Testes in Relation to Age: Morphological and Immunohistochemical Observation

Objective: The purpose of this research was to observe the age-related growth and histomorphological changes in Japanese quail testes from post-hatching to sexual maturity as well as spermatogenesis.Materials and Methods: After collection, the testes weight, length, width, and index analysis were performed, and histomorphological, histological and immunohistochemical observations were conducted using hematoxylin-eosin, PAS-hematoxylin, and anti-Hsc70t staining, respectively at different ages.Results: The weight of the testes increased gradually with age and reached a peak at 70 days. The length and width of the testes were maximal at 70 days. The testis index was positively correlated with age and body weight (BW) toward sexual maturity. Histologically, at 15 days of age, the seminiferous tubules (STs) remained in immature state with undifferentiated spermatogenic cells of only one to two layers of epithelial cells. At 28 days, the spermatogenic cells were differentiated from spermatogonia to spermatocytes. At 42 days, remarkable enlargement of STs with a series of spermatogenic cell development up to the round spermatids and Leydig cells in the interstitial region. Finally, at 70 days, extremely enlarged STs containing all stages of spermatogenic cells. The diameter and height of STs were maximal at 70 days than that of 42 days of age. A strong Hsc 70t immunoreaction was found in the round to elongated spermatids/spermatozoa near to the lumen of STs, clearly indicating well-characterized spermatogenesis in quail testis at 70 days of age.Conclusion: The findings may contribute to our understanding of quail’s spermatology and provide basic knowledge for reproductive toxicology, physiology and pathology studies.

The need for a global COVID-19 maternal immunisation research plan

The need for a global COVID-19 maternal immunisation research plan

Optimizing Pharmacology Studies in Pregnant and Lactating Women Using Lessons From HIV: A Consensus Statement.

Information on the extent of drug exposure to mothers and infants during pregnancy and lactation normally becomes available years after regulatory approval of a drug. Clinicians face knowledge gaps on drug selection and dosing in pregnancy and infant exposure during breastfeeding. Physiological changes during pregnancy often result in lower drug exposures of antiretrovirals, and in some cases a risk of reduced virologic efficacy. The International Maternal Pediatric Adolescent AIDS Clinical Trials (IMPAACT) network and the World Health Organization (WHO)–convened Pediatric Antiretrovirals Working Group collaboratively organized a workshop of key stakeholders in June 2019 to define key standards to generate pharmacology data for antiretrovirals to be used among pregnant and lactating women; review the antiretroviral product pipeline; describe key gaps for use in low‐income and middle‐income countries; and identify opportunities to undertake optimal studies allowing for rapid implementation in the clinical field. We discussed ethical and regulatory principles, systemic approaches to obtaining data for pregnancy pharmacokinetic/pharmacodynamic (PK/PD) studies, control groups, optimal sampling times during pregnancy, and pharmacokinetic parameters to be considered as primary end points in pregnancy PK/PD studies. For lactation studies, the type of milk to collect, ascertainment of maternal adherence, and optimal PK methods to estimate exposure were discussed. Participants strongly recommended completion of preclinical reproductive toxicology studies prior to phase III, to allow study protocols to include pregnant women or to allow women who become pregnant after enrolment to continue in the trial. The meeting concluded by developing an algorithm for design and interpretation of results and noted that recruitment of pregnant and lactating women into clinical trials is critical.

Secnidazole, an Approved Single Dose Drug for Bacterial Vaginosis, Does Not Cause Reproductive Toxicity in Animals [16A

INTRODUCTION: Single-dose oral secnidazole 2 g, has recently been approved in the US for treatment of bacterial vaginosis (BV) in adult women. BV is associated with an increased risk of several pathological gynecological conditions as well as major adverse outcomes during pregnancy, where it is associated with a two-fold increased risk of preterm birth and a six-fold increased risk of miscarriage. In order to inform patient labeling, reproductive toxicology studies have been conducted. METHODS: A complete reproductive toxicology program required for patient labeling was conducted. Rats and rabbits were fed varying doses of secnidazole, 0 to 1000 mg/kg/day and 0 to 100 mg/kg/day, respectively, leading up to and throughout gestation. Maternal examinations included clinical observations and survival, food consumption, and parturition. Data obtained from the first-generation (F1) pups included viability, body weight, neurobehavioral and reproductive function. Data including clinical signs, survival and body weights were also obtained for the second generation pups derived from F1 offspring. Adverse events associated secnidazole were measured. RESULTS: Secnidazole showed no reproductive toxicity in animal models. There was no effect on weight, growth, and food consumption for animals administered secnidazole, up to 300 mg/kg/day. There were no effects on survival, intrauterine growth, or external fetal morphology at any dose. CONCLUSION: There was no evidence of secnidazole toxicity in fertility and pre- and postnatal reproductive toxicology. In addition, there were no adverse developmental outcomes when secnidazole was administered orally to pregnant rats and rabbits during organogenesis at doses up to 4 times the clinical dose.

Re-evaluation of name of hydrogenated poly-1-decene (E 907) as food additive.

The Panel on Food Additives and Flavourings added to food (FAF) provided a scientific opinion re‐evaluating the safety of hydrogenated poly‐1‐decene (E 907) when used as a food additive. Hydrogenated poly‐1‐decene (E 907) is authorised as a food additive in the EU in accordance with Annex II to Regulation (EC) No 1333/2008. Hydrogenated poly‐1‐decene is of low acute toxicity and does not raise concern for genotoxicity. Toxicity and carcinogenicity, as well as reproductive and developmental toxicological studies, were not available; therefore, the Panel based the derivation of the acceptable daily intake (ADI) on the no observed adverse effect level (NOAEL) identified in the subchronic study in rats and established an ADI of 20 mg/kg bw per day. Dietary exposure to hydrogenated poly‐1‐decene (E 907) from its use as a food additive was calculated based on regulatory maximum level exposure assessment scenario. Mean exposure to hydrogenated poly‐1‐decene (E 907) from its use as a food additive ranged from no exposure in infants to 2.35 mg/kg bw per day in toddlers. The high exposure to hydrogenated poly‐1‐decene (E 907) ranged from 0 mg/kg bw per day in infants and adults to 6.69 mg/kg bw per day in toddlers. The exposure estimates in the regulatory maximum level exposure assessment scenario did not exceed the ADI of 20 mg/kg bw per day for all population groups. The Panel concluded that the exposure to hydrogenated poly‐1‐decene (E 907) does not raise a safety concern when used at the maximum permitted levels.