Ensuring the safety of new pharmaceuticals and therapies is paramount in drug discovery. Takeda’s Discovery Toxicology plays a crucial role in reducing safety-related risks by focusing on the quality of drug discovery targets. This involves identifying potential toxicities early in the development phase, enabling the mitigation of risks before they impact later stages of drug development. The Target Safety Review (TSR) initiates the Target Safety Assessment (TSA) process, providing a strategic assessment of safety concerns arising from target modulation. The TSR types range from comprehensive evaluations to simplified versions, assessing on-target and off-target effects, project background, biological information, and chemistry. Importantly, the TSR includes risk ranking and de-risking plans. Risks are ranked based on their probability and impact, enabling informed decision-making throughout the drug development process. This minireview discusses several case studies at Takeda, illustrating the importance of early risk identification. Of course, challenges remain, such as the appropriate timing of TSR creation, limited human on-target information, the need for effective risk assessment methods, incorporation of safety indicators into pharmacological studies, and addressing specific background risks in patient populations. Nonetheless, utilizing the TSR and TSA processes ensures a streamlined and safer drug development journey and provides a comprehensive approach to effectively address potential safety risks.

Neonatal growth and development are significantly influenced by maternal care and breastfeeding. Our previous research showed that maternal exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in dams reduced prolactin (PRL) levels, nursing behavior, and milk production during lactation. Intracerebroventricular infusion of PRL in TCDD-exposed dams partially reversed these defects in mothers and offspring. However, the mechanism by which maternal TCCD exposure causes reduced PRL levels and multigenerational effects remains unclear. This study aimed to investigate the multigenerational effects of maternal TCDD exposure and sought solutions to the developmental issues arising from low PRL levels due to TCDD exposure during gestation. Oral administration of TCDD (1 µg/kg) to pregnant rats on gestational day 15 (F₀ dams) led to decreased PRL concentrations in female offspring (F₁/F₂) and impaired maternal licking behavior when F₁ females had given birth, resulting in adverse effects on body weight and short-term memory in F₂/F₃ offspring. Aripiprazole (ARI), a partial dopamine D2 receptor (D2R) agonist, increases PRL levels by inhibiting the effect of dopamine during PRL synthesis and secretion. Importantly, administration of ARI to F₀ dams not only restored PRL levels, nursing behavior, and milk volume in the treated mothers but also mitigated the developmental deficits observed in F₂/F₃ offspring. These findings highlight the critical role of PRL in maternal care and offspring development and suggest that ARI could be a potential therapeutic intervention to mitigate the effects of TCDD-induced multi-generational developmental disruptions.

Background: Acute inflammation is induced by lipopolysaccharide (LPS), accompanied by activation of platelets. Carbon monoxide (CO), an endogenous bioactive gas, has been shown to bind to mitochondria and exert anti-inflammatory effects. In this study, we investigated the effect of CO on the mitochondrial membrane potential of platelets activated by LPS. Methods: To elucidate the mechanism of the LPS-induced platelet response, human platelets were stimulated with LPS (10 μg/mL). Human platelet concentrates were divided into four groups: Untreated (Control), LPS-treated (LPS), LPS and CO-dissolved solution-treated (LPS + CO), and LPS and exogenous carbon monoxide releasing molecule-2-treated (LPS + CORM-2) groups. After 30 minutes, lactate levels and mitochondrial membrane potential (ΔΨm) in the platelets were measured. Morphological changes of the platelets were also observed using transmission electron microscopy. Results: In the LPS group, the proportion of platelets with depolarized ΔΨm increased, accompanied by elevated lactate levels compared with the control group. On the other hand, in the LPS+CO and LPS+CORM-2 groups, the proportion of depolarized platelets did not significantly increase, and lactate levels were not significantly elevated. Morphologically, elongating pseudopods and cell condensation were observed in the LPS group, however, these changes were not induced in the LPS+CO and LPS+CORM-2 groups. Conclusion: These results suggest that CO prevents a decrease in the platelet ΔΨm and thereby inhibits platelet activation by LPS treatment.

Osteoarthritis (OA) is a degenerative joint condition characterized by an increased density of the subchondral osseous tissue, cartilage degradation, and synovial membrane inflammation. Ginkgetin, a bioactive compound derived from Ginkgo biloba, exhibits notable anti-inflammatory properties in various disease models. In the current study, we aimed to determine the therapeutic potential of ginkgetin in mitigating IL-1β-induced inflammatory responses in human osteoarthritis chondrocytes. Our findings demonstrated that ginkgetin significantly inhibited the IL-1β-induced production of prostaglandin E2 (PGE2) and nitric oxide (NO). Additionally, ginkgetin downregulated the expression of IL-1β-induced proinflammatory mediators and cartilage-degrading enzymes. Furthermore, ginkgetin attenuated the degradation of key extracellular matrix components, including aggrecan and type II collagen. Mechanistically, ginkgetin exerted its protective effects by markedly suppressing the activation of the PI3K/AKT/NF-κB signaling pathway. Taken together, our findings demonstrated that ginkgetin ameliorates IL-1β-stimulated inflammation via modulation of the PI3K/AKT/NF-κB cascade, underscoring its viability as a promising therapeutic strategy for managing OA.

Morphological observation and classification of bone marrow cells in smear specimens is an important examination in toxicity studies for pharmaceuticals. However, acquiring the expertise for classifying bone marrow cells using light microscopy requires years of training, resulting in significant labor and time. To efficiently acquire accurate and objective data without oversight, a system for the automated detection and morphological classification of rat bone marrow cells was developed through machine learning using whole slide images (WSIs) obtained from smear specimens. Our system integrates SSD300 for object detection, VDSR for image super-resolution, and EfficientNetV2B0 for classification. WSIs of rat bone marrow smear specimens were obtained at 40× magnification using a WSI scanner. The fine-tuning of the bone marrow cell detection model using SSD300 was performed with 720 images obtained from WSIs of rat bone marrow smear specimens. The morphological classification model for 13 types of bone marrow cells using VDSR-EfficientNetV2B0 was optimized with a total of 144,000 cell images. The system for detection of bone mallow cells achieved an average precision of 79%. Additionally, the morphological classification achieved an accuracy of 98% when compared to expert classification. Our algorithm enabled the automated classification of cells on rat bone marrow smear specimens with extremely high accuracy and in a short time, approximately 80 sec, to classify 5,000 cells per image, without oversight. This capability suggests that the algorithm could potentially be utilized as a supportive tool for the toxicity evaluation of bone marrow smear specimens.