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Tumor Discovery A comprehensive review of bexarotene

The incorporation of bexarotene into nanomatrix solid stimulation tests is needed to understand bexarotene’s
dispersions with natural and synthetic polymers like locust role in central hypothyroidism (CH). These findings
bean gum has demonstrated a substantial enhancement contribute to understanding and imply the importance of
in solubility, suggesting their suitability for personalized TSH monitoring during bexarotene treatment for CTCL,
medicine applications . In addition, the utilization of requiring additional investigation for optimal monitoring
[60]
predictive models, such as the CocrystalGCN model, and treatment approaches .
[63]
facilitated the discovery of new bexarotene cocrystals
with superior solubility and dissolution properties. 8.2.2. Characteristics and strategies of using
These cocrystals exhibited higher bioavailability than bexarotene
commercially available bexarotene powder, addressing The study provides the first report on bexarotene-induced
[61]
absorption challenges for water-insoluble drugs . CH in Japanese CTCL patients. Despite limitations such as
To conclude, these formulations offer promising small sample size and retrospective analysis, the findings
strategies to overcome the limitations associated with are valuable for an Asian population. Notably, TSH
bexarotene, such as poor solubility, bioavailability, and values significantly decreased after 1 week of bexarotene
targeted drug delivery. They provide enhanced therapeutic treatment, indicating the potential for an early decline in
effectiveness in the treatment of various disorders, paving thyroid function parameters. Correlations between pre-
the way for improved patient outcomes. treatment TSH values and subsequent FT4 levels highlight
the sensitivity of TSH as a marker for thyroid capacity. The
8. Recent pharmacological findings study suggests that a preventive levothyroxine regimen
8.1. Bexarotene cytotoxicity may be appropriate for patients with lower normal range
FT4 or higher pre-treatment TSH values. The observed
Bexarotene, possessing a polyaromatic structure, displayed occurrence of hypothyroidism after relatively low doses
stability in an ethanol solution under experimental of bexarotene and the potential influence of RXRγ1
conditions following ultraviolet (UV) exposure, except genetic polymorphism warrants further investigation.
when TiO2 and ZnO were present. The concentration of In addition, iodine sufficiency may mitigate bexarotene-
bexarotene in gel formulation remained unchanged when induced hypothyroidism. Importantly, the study proposes
subjected to BP-1, BP-2, 4-MBC, and BP-4 chemical filters, that TSH values at 1 week post-treatment could predict
but degradation occurred in the presence of avobenzone thyroid function at 1 month, emphasizing the need for
or physical UV filters. This investigation highlighted the regular monitoring. These findings have implications for
influence of UV absorbers on bexarotene’s stability in the managing thyroid function in CTCL patients undergoing
formulation. Non-cancerous murine fibroblasts exhibited bexarotene treatment in Japan .
[64]
notable inhibition in a concentration-dependent manner
when exposed to bexarotene, while the solution resulting 8.3. Myelin repair and cognitive restoration
from bexarotene’s photodegradation demonstrated a more In this study, the authors investigated the neurological
pronounced antiproliferative effect, particularly at the impairments associated with cancer treatment and
highest concentration employed . explored potential interventions to mitigate these effects.
[62]
8.2. Bexarotene-induced hypothyroidism They used a mouse model to show that cisplatin treatment,
commonly used in chemotherapy, resulted in cognitive and
8.2.1. Thyrotropin-releasing hormone (TRH) sensorimotor deficits, along with changes in white matter
stimulation test density and myelin structure. To address these deficits,
The study demonstrated that bexarotene treatment the researchers administered the RXR agonist bexarotene
in patients with CTCL leads to a blunted response of and found that it effectively restored cognitive function,
thyroid-stimulating hormone (TSH) to TRH stimulation, sensorimotor performance, and myelin structure after
supporting the hypothesis of pituitary hypothyroidism. cisplatin treatment. RNA sequencing analysis confirmed
TSH levels after TRH stimulation were correlated with LT4 the activation of pathways involved in myelination,
replacement dosage. However, the study has limitations, axon guidance, and synaptic function with bexarotene
including a small sample size and a lack of criteria treatment. Importantly, bexarotene is already approved for
to differentiate between pituitary and hypothalamic other medical conditions, indicating its potential for rapid
hypothyroidism. Nonetheless, the study suggests that TSH clinical translation. The study also identified myelination-
levels from TRH stimulation accurately reflect residual associated genes, such as CDH1, prostaglandin D2
pituitary-thyroid function during bexarotene treatment. synthase (PTGDS), and MAL, which may contribute to
Further, research with larger studies and serial TRH myelin decompaction. The beneficial effects of bexarotene

Volume 2 Issue 2 (2023) 9 https://doi.org/10.36922/td.0436