Clinical pharmacokinetics of docetaxel

Insights into interactions between taxanes and P-glycoprotein using biophysical and in silico methods

Multidrug resistance mediated by P-glycoprotein (Pgp) is a significant obstacle to cancer chemotherapy. Taxane drugs, including paclitaxel, docetaxel, and cabazitaxel, are used to treat multiple types of cancer. All taxane drugs are Pgp substrates, but cabazitaxel is also a Pgp inhibitor, indicating potential differential interactions between Pgp and different taxanes. Here, we showed for the first time that cabazitaxel had a partial inhibitory effect on the ATPase activity at concentrations higher than 10 µM. We found the KD of paclitaxel, docetaxel, and cabazitaxel to Pgp are 0.85 µM, 40.59 µM, and 13.53 µM, respectively. Based on acrylamide quenching, paclitaxel induced Pgp into a wide inward-facing open conformation at a high concentration but a slightly occluded conformation at lower concentrations. Both docetaxel and cabazitaxel shifted Pgp towards occluded states, each drug resulting in a unique degree of occlusion. Furthermore, molecular docking and energy calculations revealed that cabazitaxel binds with the "access tunnel" and blocks the subsequent nucleotide-binding domain dimerization. Our results indicate that the preference of taxanes for different binding sites on Pgp leads to distinct transport mechanisms. These results provide valuable insight into the interaction between taxanes and Pgp, which will enhance future drug development.

Opportunities for Precision Dosing of Cytotoxic Drugs in Non-Small Cell Lung Cancer: Bridging the Gap in Precision Medicine

Precision dosing of classical cytotoxic drugs in oncology remains underdeveloped, especially in treating non-small cell lung cancer (NSCLC). Despite advancements in targeted therapy and immunotherapy, classical cytotoxic agents continue to play a critical role in NSCLC treatment. However, the current body surface area (BSA)-based dosing of these agents fails to adequately address interindividual variability in pharmacokinetics. By better considering patient characteristics, treatment outcomes can be improved, reducing risks of under-exposure and over-exposure. This narrative review explores opportunities for precision dosing for key cytotoxic agents used in NSCLC treatment: cisplatin, carboplatin, pemetrexed, docetaxel, (nab-)paclitaxel, gemcitabine, and vinorelbine. A comprehensive review of regulatory reports and an extensive literature search were conducted to evaluate current dosing practices, pharmacokinetics, pharmacodynamics, and exposure-response relationships. Our findings highlight promising developments in precision dosing, although the number of directly implementable strategies remains limited. The most compelling evidence supports using the biomarker cystatin C for more precise carboplatin dosing and adopting weekly dosing schedules for docetaxel, paclitaxel, and nab-paclitaxel. Additionally, we recommend direct implementation of therapeutic drug monitoring (TDM)-guided dosing for paclitaxel. This review stresses the urgent need to reassess conventional dosing paradigms for classical cytotoxic agents to better align with the principles of the precision dosing framework. Our recommendations show the potential of precision dosing to improve NSCLC treatment, addressing gaps in the current dosing of classical cytotoxic drugs. Given the large NSCLC patient population, optimising the dosing of these agents could significantly improve treatment outcomes and reduce toxicity for many patients.

PLGA/TPGS nanoparticles for docetaxel delivery: The pegylation effect on nanoparticle physicochemical properties and uptake and cytotoxicity in prostate cancer cells

Prostate cancer is the most common malignancy in men worldwide and docetaxel (DTX) is the treatment of choice. However, both the drug and formulation excipients for drug solubilization can cause side effects. In this context, the development of polymeric nanoparticles offers advantages to improve drug delivery and reduce toxicity. In the present work, factorial design was used to evaluate the effect of the amount of poly(L-lactide-co-glycolide) (PLGA) or poly(L-lactide-co-glycolide acid-polyethylene glycol) (PLGA-PEG), D-Alpha-Tocopheryl Polyethylene Glycol Succinate (TPGS) and ratio between aqueous and oily phases on the nanoparticle characteristics. The nanocarriers were characterized regarding particle size, polydispersity, zeta potential, DTX encapsulation efficiency, morphology by transmission electron microscopy, DSC, TGA and FTIR. It was evaluated in vitro for cytotoxicity and cellular uptake in prostate cancer cells. Pegylated nanoparticles, which have a different composition (TPGS%, AP:OP ratio), reduced the nanoparticle size to 105.97 ± 5.16 nm, in PDI 0.13 ± 0.03, zeta potential of -34.73 ± 1.19 mV and increased the encapsulation efficiency to 96.78 ± 1.20%. Characterization by DSC, TGA and FTIR confirmed drug encapsulation and showed colloidal stability. Pegylated nanoparticles were more stable upon serum incubation and adsorbed less proteins. In conclusion, the pegylation of the nanoparticles affected the physicochemical parameters. Also, the pegylation of nanoparticles decreased uptake by macrophages. Finally, cellular uptake and cell cytotoxicity were higher in tumor cells when compared to non-tumor cells, although they were not affected by pegylation.

Novel insights into taxane pharmacology: An update on drug resistance mechanisms, immunomodulation and drug delivery strategies

Taxanes are effective in several solid tumors. Paclitaxel, the main clinically available taxane, was approved in the early nineties, for the treatment of ovarian cancer and later on, together with the analogs docetaxel and cabazitaxel, for other malignancies. By interfering with microtubule function and impairing the separation of sister cells at mitosis, taxanes act as antimitotic agents, thereby counteracting the high proliferation rate of cancer cells. The action of taxanes goes beyond their antimitotic function because their main cellular targets, the microtubules, participate in multiple processes such as intracellular transport and cell shape maintenance. The clinical efficacy of taxanes is limited by the development of multiple resistance mechanisms. Among these, extracellular vesicles have emerged as new players. In addition, taxane metronomic schedules shows an impact on the tumor microenvironment reflected by antiangiogenic and immunomodulatory effects, an aspect of growing interest considering their inclusion in treatment regimens with immunotherapeutics. Preclinical studies have paved the bases for synergistic combinations of taxanes both with conventional and targeted agents. A variety of drug delivery strategies have provided novel opportunities to increase the drug activity. The ability of taxanes to orchestrate different cellular effects amenable to modulation suggests novel options to improve cures in lethal malignancies.

Therapeutic drug monitoring of docetaxel administered for breast cancer in a patient receiving rifampicin and clarithromycin to treat nontuberculous mycobacteriosis: A case report

Docetaxel is metabolized by cytochrome P450 3A4 (CYP3A4), and is transported by organic anion transporting peptides (OATPs) and ABCB1, and its blood concentration is known to affect the risk of some docetaxel-related adverse drug reactions (ADRs). Thus, the concomitant use of docetaxel with drugs that inhibit or induce these transporters or CYP3A4 requires careful attention. A 58-year-old woman was receiving clarithromycin (400 mg twice daily), rifampicin (450 mg once daily) and ethambutol (500 mg once daily) for nontuberculous mycobacteriosis. The patient was diagnosed as having stage IV HER2-positive breast cancer, which was treated with a regimen of trastuzumab (8 mg/kg), pertuzumab (first dose: 840 mg; second dose onward: 420 mg) and docetaxel (75 mg/m2) every 3 weeks. To predict the risk of serious drug interactions with rifampicin and clarithromycin, the blood concentration of docetaxel was analyzed after administration of the first course. The docetaxel levels at 22 and 159 h after administration were 36.1 and 6.5 ng/ml, respectively, which were higher than previously reported data. In addition, the calculated elimination half-life of 55.7 h was ~3 times longer than previously reported data. Although the docetaxel level was high, the same dosage was used in subsequent courses because no serious ADRs were observed during the first course of therapy. After 4 months of chemotherapy, the patient received complete remission. In conclusion, concomitant use of rifampicin and clarithromycin may increase the blood concentration of docetaxel.

aPD-L1-facilitated theranostic and tumor microenvironment remodeling of pancreatic cancer via docetaxel-loaded phase-transformation nanoparticles triggered by low-intensity pulsed ultrasound

Early diagnosis of pancreatic ductal adenocarcinoma (PDAC) is challenging because of its depth, which often leads to misdiagnosis during ultrasound examinations. The unique PDAC tumor microenvironment (TME) is characterized by significant fibrous tissue growth, and high interstitial pressure hinders drug penetration into tumors. Additionally, hypoxia and immune suppression within the tumor contribute to poor responses to radiotherapy and chemotherapy, ultimately leading to an unfavorable prognosis. In this study, aPD-L1-modified docetaxel and perfluoropentane-loaded liquid‒vapor phase-transformation lipid nanoparticles (aPDL1-DTX/PFP@Lipid) were synthesized and had an average diameter of 61.63 nm with 84.3% antibody modification. We demonstrated that the nanoparticles (NPs) exhibited excellent PDAC-targeting capabilities both in vitro and in vivo. Upon exposure to low-intensity pulsed ultrasound (LIPUS) stimulation, the NPs underwent a phase transformation to form microbubbles with substantial molecular ultrasound diagnostic effects, and combined treatment resulted in a tumor growth inhibition rate of 88.91%. This treatment strategy also led to the infiltration of CD8+ T cells, the downregulation of Treg cells, the promotion of M1 macrophage polarization, the inhibition of fibrosis to reduce tumor stromal pressure, and the facilitation of perfluoropentane (PFP) gasification to release O2 and improve tumor hypoxia. In conclusion, aPD-L1-modified liquid‒vapor phase-transformation nanoparticles loaded with docetaxel (DTX) and PFP were successfully combined with ultrasound for the molecular diagnosis and targeted treatment of PDAC. aPDL1-DTX/PFP@Lipid could reshape the PDAC TME, offering a new approach for ultrasound-mediated diagnosis and treatment with promising clinical applications.

Clinical Implications of Co-administering Apixaban with Key Interacting Medications

With many available data sources, clinicians need to consider the benefit-risk profile of individual anticoagulants when balancing the need for anticoagulation, including evaluating the risks in patients with comorbidities and potential drug-drug interactions. This narrative review presents clinical data across multiple phases of drug development for the use of apixaban, a selective factor Xa inhibitor, when taken concomitantly with other agents, and evaluates the benefit-risk profile of apixaban with these interacting medications. Key subgroup analyses from the phase 3 ARISTOTLE trial (NCT00412984) are presented using data from patients who received either concomitant inhibitors or inducers of cytochrome P450 3A4 and/or P‑glycoprotein. We also review the available evidence for the use of apixaban in patients with cancer-associated thromboembolism, as well as the use of apixaban in patients with COVID-19.

A sub-pharmacological test dose does not predict individual docetaxel exposure in prostate cancer patients

PURPOSE

Docetaxel is a cytotoxic drug used for first-line treatment of various malignancies. It has a narrow therapeutic index and shows wide interpatient variability in clearance and toxicity. Tools for individual dose optimization are needed to maximize efficacy and avoid toxicity.

METHODS

We performed a proof-of-concept study (EudraCT 2016-003785-77) to evaluate whether pharmacokinetics after a sub-pharmacological test dose of 1000 µg docetaxel (millidose) could be used to predict therapeutic dose exposure. Thirty prostate cancer patients eligible for treatment with docetaxel as part of routine clinical care were included. An intravenous docetaxel millidose was administered 1-7 days prior to therapeutic docetaxel. After both doses plasma docetaxel concentrations were measured by ultra- high performance liquid chromatography-tandem mass spectrometry. The docetaxel clearance was estimated with non-linear mixed effects modeling.

RESULTS

Geometric mean docetaxel clearance was 57.9 L/h (GCV 78.6%) after admission of a millidose and 40.3 L/h (GCV 60.7%) after admission of a therapeutic dose. The millidose and therapeutic dose in a single patient were not significantly correlated (Spearman's rho R = 0.02, P = 0.92).

CONCLUSION

Docetaxel pharmacokinetics at milli- and therapeutic dose level showed insufficient correlation for individual dose optimization. However, the clearance of a docetaxel millidose and full dose are within the same order of magnitude. Therefore, docetaxel millidose pharmacokinetics could potentially facilitate prediction of docetaxel pharmacokinetics at a population level in situations where therapeutic dose levels are impractical, such as pharmacokinetic drug-drug interaction studies or pediatric studies.

Docetaxel, cyclophosphamide, and epirubicin: application of PBPK modeling to gain new insights for drug-drug interactions

The new adjuvant chemotherapy of docetaxel, epirubicin, and cyclophosphamide has been recommended for treating breast cancer. It is necessary to investigate the potential drug-drug Interactions (DDIs) since they have a narrow therapeutic window in which slight differences in exposure might result in significant differences in treatment efficacy and tolerability. To guide clinical rational drug use, this study aimed to evaluate the DDI potentials of docetaxel, cyclophosphamide, and epirubicin in cancer patients using physiologically based pharmacokinetic (PBPK) models. The GastroPlus™ was used to develop the PBPK models, which were refined and validated with observed data. The established PBPK models accurately described the pharmacokinetics (PKs) of three drugs in cancer patients, and the predicted-to-observed ratios of all the PK parameters met the acceptance criterion. The PBPK model predicted no significant changes in plasma concentrations of these drugs during co-administration, which was consistent with the observed clinical phenomenon. Besides, the verified PBPK models were then used to predict the effect of other Cytochrome P450 3A4 (CYP3A4) inhibitors/inducers on these drug exposures. In the DDI simulation, strong CYP3A4 modulators changed the exposure of three drugs by 0.71-1.61 fold. Therefore, patients receiving these drugs in combination with strong CYP3A4 inhibitors should be monitored regularly to prevent adverse reactions. Furthermore, co-administration of docetaxel, cyclophosphamide, or epirubicin with strong CYP3A4 inducers should be avoided. In conclusion, the PBPK models can be used to further investigate the DDI potential of each drug and to develop dosage recommendations for concurrent usage by additional perpetrators or victims.

Using maximum plasma concentration (Cmax) to personalize taxane treatment and reduce toxicity

Taxanes are a widely used class of anticancer agents that play a vital role in the treatment of a variety of cancers. However, toxicity remains a major concern of using taxane drugs as some toxicities are highly prevalent, they can not only adversely affect patient prognosis but also compromise the overall treatment plan. Among all kinds of factors that associated with taxane toxicity, taxane exposure has been extensively studied, with different pharmacokinetic (PK) parameters being used as toxicity predictors. Compared to other widely used predictors such as the area under the drug plasma concentration curve versus time (AUC) and time above threshold plasma drug concentration, maximum plasma concentration (Cmax) is easier to collect and shows promise for use in clinical practice. In this article, we review the previous research on using Cmax to predict taxane treatment outcomes. While Cmax and toxicity have been extensively studied, research on the relationship between Cmax and efficacy is lacking. Most of the articles find a positive relationship between Cmax and toxicity but several articles have contradictory findings. Future clinical trials are needed to validate the relationship between Cmax and treatment outcome and determine whether Cmax can serve as a useful surrogate endpoint of taxane treatment efficacy.

Boosting antitumor efficacy using docetaxel-loaded nanoplatforms: from cancer therapy to regenerative medicine approaches

The intersection of nanotechnology and pharmacology has revolutionized the delivery and efficacy of chemotherapeutic agents, notably docetaxel, a key drug in cancer treatment. Traditionally limited by poor solubility and significant side effects, docetaxel's therapeutic potential has been significantly enhanced through its incorporation into nanoplatforms, such as nanofibers and nanoparticles. This advancement offers targeted delivery, controlled release, and improved bioavailability, dramatically reducing systemic toxicity and enhancing patient outcomes. Nanofibers provide a versatile scaffold for the controlled release of docetaxel, utilizing techniques like electrospinning to tailor drug release profiles. Nanoparticles, on the other hand, enable precise drug delivery to tumor cells, minimizing damage to healthy tissues through sophisticated encapsulation methods such as nanoprecipitation and emulsion. These nanotechnologies not only improve the pharmacokinetic properties of docetaxel but also open new avenues in regenerative medicine by facilitating targeted therapy and cellular regeneration. This narrative review highlights the transformative impact of docetaxel-loaded nanoplatforms in oncology and beyond, showcasing the potential of nanotechnology to overcome the limitations of traditional chemotherapy and pave the way for future innovations in drug delivery and regenerative therapies. Through these advancements, nanotechnology promises a new era of precision medicine, enhancing the efficacy of cancer treatments while minimizing adverse effects.

Prostate cancer therapy outcome prediction: are miRNAs a suitable guide for therapeutic decisions?

BACKGROUND

Radical prostatectomy, radiotherapy, chemotherapy, and androgen-deprivation therapy are among the most common treatment options for different forms of prostate cancer (PCa). However, making therapeutic decisions is difficult due to the lack of reliable prediction markers indicating therapy outcomes in clinical practice. The involvement of miRNAs in all mechanisms of the PCa development and their easy detection characterize them as attractive PCa biomarkers. Although there are extensive data on the role of miRNAs in PCa therapy resistance and sensitivity development, the issues of whether they could be used as a guide for therapy choice and, if so, how we can progress toward this goal, remain unclear. Thus, generalizable reviews and studies which summarize, compare, and analyze data on miRNA involvement in responses to different types of PCa therapies are required.

OBJECTIVES

Data on the involvement of miRNAs in therapy responses, on the role of cross-miRNA expression in different therapies, and on miRNA targets were analyzed in order to determine the miRNA-related factors which can lend perspective to the future development of personalized predictors of PCa sensitivity/resistance to therapies.

MATERIALS AND METHODS

The data available on the miRNAs associated with different PCa therapies (resistance and sensitivity therapies) are summarized and analyzed in this study, including analyses using bioinformatics resources. Special attention was dedicated to the mechanisms of the development of therapy resistance.

RESULTS AND DISCUSSION

A comprehensive combined analysis of the current data revealed a panel of miRNAs that were shown to be most closely associated with the PCa therapy response and were found to regulate the genes involved in PCa development via cell proliferation regulation, epithelial-mesenchymal transition (EMT), apoptosis, cell-cycle progression, angiogenesis, metastasis and invasion regulation, androgen-independent development, and colony formation.

CONCLUSION

The selected miRNA-based panel has the potential to be a guide for therapeutic decision making in the effective treatment of PCa.

Overcoming the Blood-Brain Tumor Barrier with Docetaxel-Loaded Mesoporous Silica Nanoparticles for Treatment of Temozolomide-Resistant Glioblastoma

While temozolomide (TMZ) has been a cornerstone in the treatment of newly diagnosed glioblastoma (GBM), a significant challenge has been the emergence of resistance to TMZ, which compromises its clinical benefits. Additionally, the nonspecificity of TMZ can lead to detrimental side effects. Although TMZ is capable of penetrating the blood-brain barrier (BBB), our research addresses the need for targeted therapy to circumvent resistance mechanisms and reduce off-target effects. This study introduces the use of PEGylated mesoporous silica nanoparticles (MSN) with octyl group modifications (C8-MSN) as a nanocarrier system for the delivery of docetaxel (DTX), providing a novel approach for treating TMZ-resistant GBM. Our findings reveal that C8-MSN is biocompatible in vitro, and DTX@C8-MSN shows no hemolytic activity at therapeutic concentrations, maintaining efficacy against GBM cells. Crucially, in vivo imaging demonstrates preferential accumulation of C8-MSN within the tumor region, suggesting enhanced permeability across the blood-brain tumor barrier (BBTB). When administered to orthotopic glioma mouse models, DTX@C8-MSN notably prolongs survival by over 50%, significantly reduces tumor volume, and decreases side effects compared to free DTX, indicating a targeted and effective approach to treatment. The apoptotic pathways activated by DTX@C8-MSN, evidenced by the increased levels of cleaved caspase-3 and PARP, point to a potent therapeutic mechanism. Collectively, the results advocate DTX@C8-MSN as a promising candidate for targeted therapy in TMZ-resistant GBM, optimizing drug delivery and bioavailability to overcome current therapeutic limitations.

A Cross-sectional Comparative Analysis of Eleven Population Pharmacokinetic Models for Docetaxel in Chinese Breast Cancer Patients

OBJECTIVE

Various population pharmacokinetic (PPK) models have been established to help determine the appropriate dosage of docetaxel, however, no clear consensus on optimal dosing has been achieved. The purpose of this study is to perform an external evaluation of published models in order to test their predictive performance, and to find an appropriate PPK model for Chinese breast cancer patients.

METHODS

A systematic literature search of docetaxel PPK models was performed using PubMed, Web of Science, China National Knowledge Infrastructure, and WanFang databases. The predictive performance of eleven identified models was evaluated using prediction-based and simulation-based diagnostics on an independent dataset (112 docetaxel concentrations from 56 breast cancer patients). The -2×log (likelihood) and Akaike information criterion were also calculated to evaluate model fit.

RESULTS

The median prediction error of eight of the eleven models was less than 10%. The model fitting results showed that the three-compartment model of Bruno et al. had the best prediction performance and that the three compartment model of Wang et al. had the best simulation effect. Furthermore, although the covariates that significantly affect PK parameters were different between them, seven models demonstrated that docetaxel PK parameters were influenced by liver function.

CONCLUSIONS

Three compartment PPK models may be predictive of optimal docetaxel dosage for Chinese breast cancer patients. However, for patients with impaired liver function, the choice of which model to use to predict the blood concentration of docetaxel still requires great care.

Utility of Physiologically Based Pharmacokinetic Modeling to Investigate the Impact of Physiological Changes of Pregnancy and Cancer on Oncology Drug Pharmacokinetics

BACKGROUND

The treatment of cancer during pregnancy remains challenging with knowledge gaps in drug dosage, safety, and efficacy due to the under-representation of this population in clinical trials. Our aim was to investigate physiological changes reported in both pregnancy and cancer populations into a PBPK modeling framework that allows for a more accurate estimation of PK changes in pregnant patients with cancer.

METHODS

Paclitaxel and docetaxel were selected to validate a population model using clinical data from pregnant patients with cancer. The validated population model was subsequently used to predict the PK of acalabrutinib in pregnant patients with cancer.

RESULTS

The Simcyp pregnancy population model reasonably predicted the PK of docetaxel in pregnant patients with cancer, while a modified model that included a 2.5-fold increase in CYP2C8 abundance, consistent with the increased expression during pregnancy, was needed to reasonably predict the PK of paclitaxel in pregnant patients with cancer. Changes in protein binding levels of patients with cancer had a minimal impact on the predicted clearance of paclitaxel and docetaxel. PBPK modeling predicted approximately 60% lower AUC and Cmax for acalabrutinib in pregnant versus non-pregnant patients with cancer.

CONCLUSIONS

Our results suggest that PBPK modeling is a promising approach to investigate the effects of pregnancy and cancer on the PK of oncology drugs and potentially inform dosing for pregnant patients with cancer. Further evaluation and refinement of the population model are needed for pregnant patients with cancer with additional compounds and clinical PK data.

Differential immunomodulatory effects of epirubicin/cyclophosphamide and docetaxel in breast cancer patients

BACKGROUND

Epirubicin/cyclophosphamide (EC) and docetaxel (D) are commonly used in a sequential regimen in the neoadjuvant treatment of early, high-risk or locally advanced breast cancer (BC). Novel approaches to increase the response rate combine this treatment with immunotherapies such as PD-1 inhibition. However, the expected stimulatory effect on lymphocytes may depend on the chemotherapy backbone. Therefore, we separately compared the immunomodulatory effects of EC and D in the setting of a randomized clinical trial.

METHODS

Tumor and blood samples of 154 patients from the ABCSG-34 trial were available (76 patients received four cycles of EC followed by four cycles of D; 78 patients get the reverse treatment sequence). Tumor-infiltrating lymphocytes, circulating lymphocytes and 14 soluble immune mediators were determined at baseline and at drug change. Furthermore, six BC cell lines were treated with E, C or D and co-cultured with immune cells.

RESULTS

Initial treatment with four cycles of EC reduced circulating B and T cells by 94% and 45%, respectively. In contrast, no comparable effects on lymphocytes were observed in patients treated with initial four cycles of D. Most immune mediators decreased under EC whereas D-treatment resulted in elevated levels of CXCL10, urokinase-type plasminogen activator (uPA) and its soluble receptor (suPAR). Accordingly, only the exposure of BC cell lines to D induced similar increases as compared to E. While treatment of BC cells with E was associated with cell shrinkage and apoptosis, D induced cell swelling and accumulation of cells in G2 phase.

CONCLUSION

The deleterious effect of EC on lymphocytes indicates strong immunosuppressive properties of this combination therapy. D, in contrast, has no effect on lymphocytes, but triggers the secretion of stimulatory proteins in vivo and in vitro, indicating a supportive effect on the immune system. Underlying differences in the induced cell death might be causal. These divergent immunomodulatory effects of epirubicin/cyclophosphamide and docetaxel should be considered when planning future combinations with immunotherapies in breast cancer.

Medium-chain triglyceride-stabilized docetaxel-loaded HSA nanoparticles effectively inhibited metastatic non-small cell lung cancer

Metastatic non-small cell lung cancer (NSCLC) is refractory with a very poor prognosis. Docetaxel (DTX) injection (Taxotere®) has been approved for the treatment of locally advanced or metastatic NSCLC. However, its clinical application is restricted by severe adverse effects and non-selective tissue distribution. In this study, we successfully developed DTX-loaded human serum albumin (HSA) nanoparticles (DNPs) with modified Nab technology, by introducing medium-chain triglyceride (MCT) as a stabilizer. The optimized formulation had a particle size of approximately 130 nm and a favorable stabilization time of more than 24 h. DNPs dissociated in circulation in a concentration-dependent manner and slowly released DTX. Compared with DTX injection, DNPs were more effectively taken up by NSCLC cells, thus exerting stronger inhibitory effects on their proliferation, adhesion, migration, and invasion. In addition, DNPs showed prolonged blood retention and increased tumor accumulation relative to DTX injection. Ultimately, DNPs produced more potent inhibitory effects on primary or metastatic tumor foci than DTX injections but caused markedly lower organ toxicity and hematotoxicity. Overall, these results support that DNPs hold great potential for the treatment of metastatic NSCLC in clinical.

Pluronic F127 and P104 Polymeric Micelles as Efficient Nanocarriers for Loading and Release of Single and Dual Antineoplastic Drugs

The potential application of biodegradable and biocompatible polymeric micelles formed by Pluronic F127 and P104 as nanocarriers of the antineoplastic drugs docetaxel (DOCE) and doxorubicin (DOXO) is presented in this work. The release profile was carried out under sink conditions at 37 °C and analyzed using the Higuchi, Korsmeyer-Peppas, and Peppas-Sahlin diffusion models. The cell viability of HeLa cells was evaluated using the proliferation cell counting kit CCK-8 assay. The formed polymeric micelles solubilized significant amounts of DOCE and DOXO, and released them in a sustained manner for 48 h, with a release profile composed of an initial rapid release within the first 12 h followed by a much slower phase the end of the experiments. In addition, the release was faster under acidic conditions. The model that best fit the experimental data was the Korsmeyer-Peppas one and denoted a drug release dominated by Fickian diffusion. When HeLa cells were exposed for 48 h to DOXO and DOCE drugs loaded inside P104 and F127 micelles, they showed lower IC₅₀ values than those reported by other researchers using polymeric nanoparticles, dendrimers or liposomes as alternative carriers, indicating that a lower drug concentration is needed to decrease cell viability by 50%.

Chemotherapeutic properties and side-effects associated with the clinical practice of terpene alkaloids: paclitaxel, docetaxel, and cabazitaxel

Over the years, many biological and synthetic agents have been explored and tested in attempts to halt the spread of cancer and/or cure it. Currently, several natural compounds have and are being considered in this regard. For example, paclitaxel is a potent anticancer drug that originates from the tree Taxus brevifolia. Paclitaxel has several derivatives, namely, docetaxel and cabazitaxel. These agents work by disrupting microtubule assembling dynamics and inducing cell cycle arrest at the G2/M phase of the cell cycle, ultimately triggering apoptosis. Such features have helped to establish paclitaxel as an authoritative therapeutic compound against neoplastic disorders. After the completion of compound (hemi) synthesis, this drug received approval for the treatment of solid tumors either alone or in combination with other agents. In this review, we explore the mechanisms of action of paclitaxel and its derivatives, the different formulations available, as well as the molecular pathways of cancer resistance, potential risks, and other therapeutic applications. In addition, the role of paclitaxel in hematological malignancies is explored, and potential limitations in the therapeutic use of paclitaxel at the clinical level are examined. Furthermore, paclitaxel is known to cause increased antigen presentation. The immunomodulatory potential of taxanes, alone or in combination with other pharmacologic agents, is explored. Despite terpene-alkaloids derivatives' anti-mitotic potential, the impact of this class of drugs on other oncogenic pathways, such as epithelial-to-mesenchymal transition and the epigenetic modulation of the transcription profile of cancer cells, is also analyzed, shedding light on potential future chemotherapeutic approaches to cancer.

Autophagy and Breast Cancer: Connected in Growth, Progression, and Therapy

Despite an increase in the incidence of breast cancer worldwide, overall prognosis has been consistently improving owing to the development of multiple targeted therapies and novel combination regimens including endocrine therapies, aromatase inhibitors, Her2-targeted therapies, and cdk4/6 inhibitors. Immunotherapy is also being actively examined for some breast cancer subtypes. This overall positive outlook is marred by the development of resistance or reduced efficacy of the drug combinations, but the underlying mechanisms are somewhat unclear. It is interesting to note that cancer cells quickly adapt and evade most therapies by activating autophagy, a catabolic process designed to recycle damaged cellular components and provide energy. In this review, we discuss the role of autophagy and autophagy-associated proteins in breast cancer growth, drug sensitivity, tumor dormancy, stemness, and recurrence. We further explore how autophagy intersects and reduces the efficacy of endocrine therapies, targeted therapies, radiotherapy, chemotherapies as well as immunotherapy via modulating various intermediate proteins, miRs, and lncRNAs. Lastly, the potential application of autophagy inhibitors and bioactive molecules to improve the anticancer effects of drugs by circumventing the cytoprotective autophagy is discussed.

Boosting the Potential of Chemotherapy in Advanced Breast Cancer Lung Metastasis via Micro-Combinatorial Hydrogel Particles

Breast cancer cell colonization of the lungs is associated with a dismal prognosis as the distributed nature of the disease and poor permeability of the metastatic foci challenge the therapeutic efficacy of small molecules, antibodies, and nanomedicines. Taking advantage of the unique physiology of the pulmonary circulation, here, micro-combinatorial hydrogel particles (µCGP) are realized via soft lithographic techniques to enhance the specific delivery of a cocktail of cytotoxic nanoparticles to metastatic foci. By cross-linking short poly(ethylene glycol) (PEG) chains with erodible linkers within a shape-defining template, a deformable and biodegradable polymeric skeleton is realized and loaded with a variety of therapeutic and imaging agents, including docetaxel-nanoparticles. In a model of advanced breast cancer lung metastasis, µCGP amplified the colocalization of docetaxel-nanoparticles with pulmonary metastatic foci, prolonged the retention of chemotoxic molecules at the diseased site, suppressed lesion growth, and boosted survival beyond 20 weeks post nodule engraftment. The flexible design and modular architecture of µCGP would allow the efficient deployment of complex combination therapies in other vascular districts too, possibly addressing metastatic diseases of different origins.

Results of Phase III Randomized Trial for Use of Docetaxel as a Radiosensitizer in Patients With Head and Neck Cancer, Unsuitable for Cisplatin-Based Chemoradiation

PURPOSE

There is a lack of published literature on systemic therapeutic options in cisplatin-ineligible patients with locally advanced head and neck squamous cell carcinoma (LAHNSCC) undergoing chemoradiation. Docetaxel was assessed as a radiosensitizer in this situation.

METHODS

This was a randomized phase II/III study. Adult patients (age ≥ 18 years) with LAHNSCC planned for chemoradiation and an Eastern Cooperative Oncology Group performance status of 0-2 and who were cisplatin-ineligible were randomly assigned in 1:1 to either radiation alone or radiation with concurrent docetaxel 15 mg/m² once weekly for a maximum of seven cycles. The primary end point was 2-year disease-free survival (DFS).

RESULTS

The study recruited 356 patients between July 2017 and May 2021. The 2-year DFS was 30.3% (95% CI, 23.6 to 37.4) versus 42% (95% CI, 34.6 to 49.2) in the RT and Docetaxel-RT arms, respectively (hazard ratio, 0.673; 95% CI, 0.521 to 0.868; P value = .002). The corresponding median overall survival (OS) was 15.3 months (95% CI, 13.1 to 22.0) and 25.5 months (95% CI, 17.6 to 32.5), respectively (log-rank P value = .035). The 2-year OS was 41.7% (95% CI, 34.1 to 49.1) versus 50.8% (95% CI, 43.1 to 58.1) in the RT and Docetaxel-RT arms, respectively (hazard ratio, 0.747; 95% CI, 0.569 to 0.980; P value = .035). There was a higher incidence of grade 3 or above mucositis (22.2% v 49.7%; P < .001), odynophagia (33.5% v 52.5%; P < .001), and dysphagia (33% v 49.7%; P = .002) with the addition of docetaxel.

CONCLUSION

The addition of docetaxel to radiation improved DFS and OS in cisplatin-ineligible patients with LAHNSCC.[Media: see text].

Design, development and clinical translation of CriPec®-based core-crosslinked polymeric micelles

Nanomedicines are used to improve the efficacy and safety of pharmacotherapeutic interventions. Unraveling the biological behavior of nanomedicines, including their biodistribution and target site accumulation, is essential to establish design criteria that contribute to superior performance. CriPec® technology is based on amphiphilic methoxy-poly(ethylene glycol)-b-poly[N-(2-hydroxypropyl) methacrylamide lactate] (mPEG-b-pHPMAmLac_n) block copolymers, which are designed to upon self-assembly covalently entrap active pharmaceutical ingredients (API) in core-crosslinked polymeric micelles (CCPM). Key features of CCPM are a prolonged circulation time, high concentrations at pathological sites, and low levels of accumulation in the majority of healthy tissues. Proprietary hydrolysable linkers allow for tunable and sustained release of entrapped API, including hydrophobic and hydrophilic small molecules, as well as peptides and oligonucleotides. Preclinical imaging experiments provided valuable information on their tumor and tissue accumulation and distribution, as well as on uptake by cancer, healthy and immune cells. The frontrunner formulation CPC634, which refers to 65 nm-sized CCPM entrapping the chemotherapeutic drug docetaxel, showed excellent pharmacokinetic properties, safety, tumor accumulation and antitumor efficacy in multiple animal models. In the clinic, CPC634 also demonstrated favorable pharmacokinetics, good tolerability, signs of efficacy, and enhanced localization in tumor tissue as compared to conventional docetaxel. PET imaging of radiolabeled CPC634 showed quantifiable accumulation in ∼50 % of tumors and metastases in advanced-stage cancer patients, and demonstrated potential for use in a theranostic setting even when applied at a companion diagnostic dose. Altogether, the preclinical and clinical results obtained to date demonstrate that mPEG-b-pHPMAmLac_n CCPM based on CriPec® technology are a potent, tunable, broadly applicable and well-tolerable platform for targeted drug delivery and improved anticancer therapy.

Lean Body Mass and Total Body Weight Versus Body Surface Area as a Determinant of Docetaxel Pharmacokinetics and Toxicity

AIM

This study examined whether anthropometric and body composition parameters such as body surface area (BSA), lean body mass (LBM), and total body weight (TBW) are correlated with docetaxel clearance and exposure by analyzing area under the curve. In addition, LBM, TBW, and a fixed dose were compared with BSA as dosing parameters for dose individualization of docetaxel.

METHODS

Thirty-six patients receiving docetaxel chemotherapy for breast or metastatic castration-resistant prostate carcinoma were included. Before treatment, LBM was measured using a dual-energy X-ray absorptiometry scanner. Blood samples were collected up to 180 minutes after dosing to analyze docetaxel concentrations and determine individual pharmacokinetic parameters.

RESULTS

No significant correlations were found between docetaxel clearance and the anthropometric and body composition variables (BSA, LBM, and TBW). The area under the curve was significantly but poorly correlated with BSA [r = 0.452 ( P = 0.016)] and TBW [r = 0.476 ( P = 0.011)]. The mean absolute percentage error and mean error of simulated dosing based on LBM and fixed dosing were not significantly different from those of BSA. For TBW, only mean absolute percentage error was significantly higher compared with dosing based on BSA (24.1 versus 17.1, P = 0.001).

CONCLUSIONS

There was no clinically relevant correlation between docetaxel pharmacokinetics and the anthropometric and body composition variables BSA, LBM, and TBW. Therefore, dose individualization of docetaxel based on LBM, TBW, or fixed dosing cannot be recommended over BSA-based dosing.

Biodegradable Magnetic Molecularly Imprinted Anticancer Drug Carrier for the Targeted Delivery of Docetaxel

Molecularly imprinted biodegradable polymers are receiving considerable attention in drug delivery due to their ability of targeted recognition and biocompatibility. This study reports the synthesis of a novel fluorescence-active magnetic molecularly imprinted drug carrier (MIDC) using a glucose-based biodegradable cross-linking agent for the delivery of anticancer drug docetaxel. The magnetic molecularly imprinted polymer (MMIP) was characterized through scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction spectroscopy, and vibrating sample magnetometry (VSM). The MMIP presented a magnetization value of 0.0059 emu g^-1 and binding capacity of 72 mg g^-1 with docetaxel. In vitro and in vivo studies were performed to observe the effectiveness of the MIDC for drug delivery. The cell viability assay suggested that the MMIP did not present toxic effects on healthy cells. The magnetic property of the MMIP allowed quick identification of the drug carrier at the target site by applying the external magnetic field to mice (after 20 min of loading) and taking X-ray images. The novel MMIP-based drug carrier could thus deliver the drug at the target site without affecting the healthy cells.

A Rare Case of Life-Threatening Extensive Mucocutaneous Adverse Reaction Induced by Docetaxel in a Breast Cancer Patient: Toxic Epidermal Necrolysis, a Case Report with Review of Literature

Fever and extensive necrosis with 30% or more epidermal involvement along with mucous membrane is known as toxic epidermal necrolysis (TEN). It is a life-threatening mucocutaneous disease and is usually drug induced. We report a rare case of docetaxel-induced TEN. A patient with metastatic breast carcinoma received single agent docetaxel and developed severe skin and mucous membrane reaction involving more than 30% of the skin, and managed conservatively in intensive care unit but she succumbed to her illness. Although common toxicities reported with docetaxel include alopecia, nail damage, myelosuppression, and erythema multiforme major, TEN after docetaxel is very rare and can be a life-threatening complication as in our case.

Interaction of Docetaxel with Phosphatidylcholine Membranes: A Combined Experimental and Computational Study

The antineoplastic drug Docetaxel is a second generation taxane which is used against a great variety of cancers. The drug is highly lipophilic and produces a great array of severe toxic effects that limit its therapeutic effectiveness. The study of the interaction between Docetaxel and membranes is very scarce, however, it is required in order to get clues in relation with its function, mechanism of toxicity and possibilities of new formulations. Using phosphatidylcholine biomimetic membranes, we examine the interaction of Docetaxel with the phospholipid bilayer combining an experimental study, employing a series of biophysical techniques like Differential Scanning Calorimetry, X-Ray Diffraction and Infrared Spectroscopy, and a Molecular Dynamics simulation. Our experimental results indicated that Docetaxel incorporated into DPPC bilayer perturbing the gel to liquid crystalline phase transition and giving rise to immiscibility when the amount of the drug is increased. The drug promotes the gel ripple phase, increasing the bilayer thickness in the fluid phase, and is also able to alter the hydrogen-bonding interactions in the interfacial region of the bilayer producing a dehydration effect. The results from computational simulation agree with the experimental ones and located the Docetaxel molecule forming small clusters in the region of the carbon 8 of the acyl chain palisade overlapping with the carbonyl region of the phospholipid. Our results support the idea that the anticancer drug is embedded into the phospholipid bilayer to a limited amount and produces structural perturbations which might affect the function of the membrane.

PET-CT Imaging of Polymeric Nanoparticle Tumor Accumulation in Patients

Several FDA/EMA-approved nanomedicines have demonstrated improved pharmacokinetics and toxicity profiles compared to their conventional chemotherapeutic counterparts. The next step to increase therapeutic efficacy depends on tumor accumulation, which can be highly heterogeneous. A clinical tool for patient stratification is urgently awaited. Therefore, a docetaxel-entrapping polymeric nanoparticle (⁸⁹ Zr-CPC634) is radiolabeled, and positron emission tomography/computed tomography (PET/CT) imaging is performed in seven patients with solid tumors with two different doses of CPC634: an on-treatment (containing 60 mg m^-2 docetaxel) and a diagnostic (1-2 mg docetaxel) dose (NCT03712423). Pharmacokinetic half-life for ⁸⁹ Zr-CPC634 is mean 97.0 ± 14.4 h on-treatment, and 62.4 ± 12.9 h for the diagnostic dose (p = 0.003). At these doses accumulation is observed in 46% and 41% of tumor lesions with a median accumulation in positive lesions 96 h post-injection of 4.94 and 4.45%IA kg^-1 (p = 0.91), respectively. In conclusion, PET/CT imaging with a diagnostic dose of ⁸⁹ Zr-CPC634 accurately reflects on-treatment tumor accumulation and thus opens the possibility for patient stratification in cancer nanomedicine with polymeric nanoparticles.

Combination treatment of docetaxel with caffeic acid phenethyl ester suppresses the survival and the proliferation of docetaxel-resistant prostate cancer cells via induction of apoptosis and metabolism interference

BACKGROUND

Docetaxel has been approved by USFDA as a first-line treatment for castration-resistant prostate cancer (CRPC) patients. Patients receiving androgen deprivation therapy along with docetaxel result in superior survival, lower serum prostate specific antigen (PSA) level, and better quality of life. However, a significant proportion of these patients ultimately develop resistance to docetaxel within months. Caffeic acid phenethyl ester (CAPE), one of the main bioactive components extracted from the propolis, has been reported to be effective for repressing the tumor growth, the migration and invasion of prostate cancer (PCa) cells, as well as the downstream signaling and stability of androgen receptor (AR). We hence determined if combination treatment of docetaxel with CAPE can suppress the proliferation and the survival of docetaxel-resistant PCa cells.

METHODS

We established docetaxel-resistant PC/DX25 and DU/DX50 CRPC cell lines from PC-3 and DU-145 human PCa cells, respectively. Proliferation assay, MTT assay, flow cytometry with Annexin V staining, Comet Assay, and nude mice xenograft model were applied to determine the effects of combination treatment on cell proliferation and survival of the docetaxel-resistant PCa cells. Micro-Western Array (MWA) and qRT-PCR were used to investigate the molecular mechanism lying underneath.

RESULTS

Combination treatment effectively suppressed the proliferation, survival and tumor growth of docetaxel-resistant PCa cells both in vitro and in nude mice. Comet assay and flow cytometry indicated that combination treatment induced apoptosis in docetaxel-resistant PCa cells. MWA and Western blotting assay revealed that combination treatment suppressed protein expression of Bcl-2, AKT2, c-Myc, apoptosis and caspase activation inhibitor (AVEN), pyruvate kinase M2 (PKM2) but increased protein expression of Bax, caspase 3, cytochrome c, glucose-6-phosphate dehydrogenase (G6PD) and acylglycerol kinase (AGK). Overexpression of Bcl-2 in the docetaxel-resistant PCa cells enhanced cell proliferation of docetaxel-resistant PCa cells under combination treatment. Analysis with qRT-PCR suggested that combination treatment decreased cholesterol biosynthesis genes DHCR24 (24-dehydrocholesterol reductase) and LSS (lanosterol synthase) but increased genes involved in glycolysis and TCA cycle.

CONCLUSIONS

Combination treatment of docetaxel with CAPE effectively suppressed the proliferation and survival of docetaxel-resistant PCa cells via inhibition of Bcl-2 and c-Myc as well as induction of metabolism interference. Combination treatment can be beneficial for patients with docetaxel-resistant PCa.

Synthesis and Characterization of Carboxymethyl Chitosan Nanosponges with Cyclodextrin Blends for Drug Solubility Improvement

This study aimed to enhance the solubility and release characteristics of docetaxel by synthesizing highly porous and stimuli responsive nanosponges, a nano-version of hydrogels with the additional qualities of both hydrogels and nano-systems. Nanosponges were prepared by the free radical polymerization technique and characterized by their solubilization efficiency, swelling studies, sol-gel studies, percentage entrapment efficiency, drug loading, FTIR, PXRD, TGA, DSC, SEM, zeta sizer and in vitro dissolution studies. In vivo toxicity study was conducted to assess the safety of the oral administration of prepared nanosponges. FTIR, TGA and DSC studies confirmed the successful grafting of components into the stable nano-polymeric network. A porous and sponge-like structure was visualized through SEM images. The particle size of the optimized formulation was observed in the range of 195 ± 3 nm. The fabricated nanosponges noticeably enhanced the drug loading and solubilization efficiency of docetaxel in aqueous media. The drug release of fabricated nanosponges was significantly higher at pH 6.8 as compared to pH 1.2 and 4.5. An acute oral toxicity study endorsed the safety of the system. Due to an efficient preparation technique, as well as its enhanced solubility, excellent physicochemical properties, improved dissolution and non-toxic nature, nanosponges could be an efficient and a promising approach for the oral delivery of poorly soluble drugs.

Inhibition of the HIF-1 Survival Pathway as a Strategy to Augment Photodynamic Therapy Efficacy

Photodynamic therapy (PDT) is a non-to-minimally invasive treatment modality that utilizes photoactivatable drugs called photosensitizers to disrupt tumors with locally photoproduced reactive oxygen species (ROS). Photosensitizer activation by light results in hyperoxidative stress and subsequent tumor cell death, vascular shutdown and hypoxia, and an antitumor immune response. However, sublethally afflicted tumor cells initiate several survival mechanisms that account for decreased PDT efficacy. The hypoxia inducible factor 1 (HIF-1) pathway is one of the most effective cell survival pathways that contributes to cell recovery from PDT-induced damage. Several hundred target genes of the HIF-1 heterodimeric complex collectively mediate processes that are involved in tumor cell survival directly and indirectly (e.g., vascularization, glucose metabolism, proliferation, and metastasis). The broad spectrum of biological ramifications culminating from the activation of HIF-1 target genes reflects the importance of HIF-1 in the context of therapeutic recalcitrance. This chapter elaborates on the involvement of HIF-1 in cancer biology, the hypoxic response mechanisms, and the role of HIF-1 in PDT. An overview of inhibitors that either directly or indirectly impede HIF-1-mediated survival signaling is provided. The inhibitors may be used as pharmacological adjuvants in combination with PDT to augment therapeutic efficacy.

Smart design approaches for orally administered lipophilic prodrugs to promote lymphatic transport

Challenges to effective delivery of drugs following oral administration has attracted growing interest over recent decades. Small molecule drugs (<1000 Da) are generally absorbed across the gastrointestinal tract into the portal blood and further transported to the systemic circulation via the liver. This can result in a significant reduction to the oral bioavailability of drugs that are metabolically labile and ultimately lead to ineffective exposure and treatment. Targeting drug delivery to the intestinal lymphatics is attracting increased attention as an alternative route of drug transportation providing multiple benefits. These include bypassing hepatic first-pass metabolism and selectively targeting disease reservoirs residing within the lymphatic system. The particular physicochemical requirements for drugs to be able to access the lymphatics after oral delivery include high lipophilicity (logP>5) and high long-chain triglyceride solubility (> 50 mg/g), properties required to enable drug association with the lipoprotein transport pathway. The majority of small molecule drugs, however, are not this lipophilic and therefore not substantially transported via the intestinal lymph. This has contributed to a growing body of investigation into prodrug approaches to deliver drugs to the lymphatic system by chemical manipulation. Optimised lipophilic prodrugs have the potential to increase lymphatic transport thereby improving oral pharmacokinetics via a reduction in first pass metabolism and may also target of disease-specific reservoirs within the lymphatics. This may provide advantages for current pharmacotherapy approaches for a wide array of pathological conditions, e.g. immune disease, cancer and metabolic disease, and also presents a promising approach for advanced vaccination strategies. In this review, specific emphasis is placed on medicinal chemistry strategies that have been successfully employed to design lipophilic prodrugs to deliberately enable lymphatic transport. Recent progress and opportunities in medicinal chemistry and drug delivery that enable new platforms for efficacious and safe delivery of drugs are critically evaluated.

Comparison and quantification of different concurrent chemotherapy regimens with radiotherapy in locally advanced non-small cell lung cancer: Clinical outcomes and theoretical results from an extended LQ and TCP model

PURPOSE

To develop a new radiobiological model and compare the efficacy of four concurrent chemotherapy regimens administered with radiotherapy in locally advanced non-small-cell lung cancer (LANSCLC) by in-field locoregional progression-free survival (LPFS).

MATERIALS AND METHODS

151 LANSCLC patients were reviewed and divided into 5 groups according to their concurrent chemotherapy regimens, including 24 patients treated with radiotherapy alone, 30 treated with concurrent 4-week etoposide-cisplatin (EP), 26 with 3-week pemetrexed-cisplatin (AP), 37 with weekly paclitaxel-cisplatin (TP) and 34 with weekly docetaxel-cisplatin (DP). In-field LPFS and toxicities were compared among groups. A novel tumor control probability (TCP) model, LQRGC, incorporating four "R"s of radiobiology, Gompertzian tumor growth and chemotherapeutic effect, was related to in-field LPFS. Chemo-induced biologically effective doses (BEDs) in LQRGC/TCP model were used to quantify the concurrent chemotherapeutic efficacy.

RESULTS

The median follow-up time was 54.5 months. The weekly DP and 4-week EP groups had favorable median in-field LPFS (EP:46.2 months, AP:30.3 months, TP:12.2 months, DP: not reached, radiotherapy alone: 12.2 months, p = 0.001). The 4-week EP group had a higher incidence of ≥grade 3 leukopenia (EP:76.7%, AP:15.4%, TP:24.3%, DP:14.7%, radiotherapy alone: 12.5%, p < 0.001) than the other four. The LQRGC/TCP model fitted well with the in-field LPFS with the average absolute and relative fitting errors of 6.36% and 12.12%. The chemo-induced BEDs of EP, AP, TP and DP were 5.17, 0.63, 1.89 and 2.52 Gy, respectively.

CONCLUSION

The LQRGC/TCP model achieved promising fitting accuracy for in-field LPFS. As quantified by the model, the 4-week EP and weekly DP showed higher chemo-induced BEDs when concurrently administered with radiotherapy in LANSCLC.

Single-Shot Local Injection of Microfragmented Fat Tissue Loaded with Paclitaxel Induces Potent Growth Inhibition of Hepatocellular Carcinoma in Nude Mice

Hepatocellular carcinoma (HCC) is poorly beneficiated by intravenous chemotherapy due to inadequate availability of drugs at the tumor site. We previously demonstrated that human micro-fragmented adipose tissue (MFAT) and its devitalized counterpart (DMFAT) could be effective natural scaffolds to deliver Paclitaxel (PTX) to tumors in both in vitro and in vivo tests, affecting cancer growth relapse. Here we tested the efficacy of DMFAT-PTX in a well-established HCC in nude mice. MFAT-PTX and DMFAT-PTX preparations were tested for anti-cancer activity in 2D and 3D assays using Hep-3B tumor cells. The efficacy of DMFAT-PTX was evaluated after a single-shot subcutaneous injection near a Hep-3B growing tumor by assessing tumor volumes, apoptosis rate, and drug pharmacokinetics in an in vivo model. Potent antiproliferative activity was seen in both in vitro 2D and 3D tests. Mice treated with DMFAT-PTX (10 mg/kg) produced potent Hep-3B growth inhibition with 33% complete tumor regressions. All treated animals experienced tumor ulceration at the site of DMFAT-PTX injection, which healed spontaneously. Lowering the drug concentration (5 mg/kg) prevented the formation of ulcers, maintaining statistically significant efficacy. Histology revealed a higher number of apoptotic cancer cells intratumorally, suggesting prolonged presence of PTX that was confirmed by the pharmacokinetic analysis. DMFAT may be a potent and valid new tool for local chemotherapy of HCC in an advanced stage of progression, also suggesting potential effectiveness in other human primary inoperable cancers.

Effect of docetaxel on mechanical properties of ovarian cancer cells

Docetaxel could inhibit the proliferation of tumor cells by targeting microtubules. The extension of cellular microtubules plays an important role in the invasion and metastasis of tumor cells. This paper aims to study the distribution and mechanical properties of cytoskeletal proteins with low concentration of docetaxel. MTT assay was used to detect the minimum drug activity concentration of docetaxel on SKOV-3 cells, fluorescence staining was used to analyze the distribution of cytoskeleton proteins, scanning electron microscopy(SEM) was used to observe the morphology of single cells, and atomic force microscopy(AFM) was used to determine the microstructure and mechanical properties of cells. The results showed that the IC₁₀ of docetaxel was 1 ng/ml. Docetaxel can effectively inhibit the formation of cell pseudopodia, hinder the indirectness between cells, reduce the cell extension area, and make the cells malformed. In addition, when AFM analyzes the effects of drugs on cell microstructure and mechanical properties, the average cell surface roughness and cell height are positively correlated with the concentration of docetaxel. Especially when the concentration was 100 ng/ml, the adhesion decreased by 37.04% and Young's modulus increased by 1.57 times compared with the control group. This may be because docetaxel leads to microtubule remodeling and membrane protein aggregation, which affects cell microstructure and increases cell strength, leading to significant changes in the mechanical properties of ovarian cells. This is of great significance to the study of the formation mechanism of tumor cell invasion and migration activities mediated by actin.

PSMA-targeted small-molecule docetaxel conjugate: Synthesis and preclinical evaluation

Prostate cancer is one of the most commonly diagnosed men's cancers and remains one of the leading causes of cancer death. The development of approaches to the treatment of this oncological disease is an ongoing process. In this work, we have carried out the selection of ligands for the creation of conjugates based on the drug docetaxel and synthesized a series of three docetaxel conjugates. In vitro cytotoxicity of these molecules was evaluated using the MTT assay. Based on the assay results, we selected the conjugate which showed cytotoxic potential close to unmodified docetaxel. At the same time, the molar solubility of the resulting compound increased up to 20 times in comparison with the drug itself. In vivo evaluation on 22Rv1 (PSMA+) xenograft model demonstrated a good potency of the synthesized conjugate to inhibit tumor growth: the inhibition turned out to be more than 80% at a dose of 30 mg/kg. Pharmacokinetic parameters of conjugate distribution were analyzed. Also, it was found that PSMA-targeted docetaxel conjugate is less toxic than docetaxel itself, the decrease of molar acute toxicity in comparison with free docetaxel was up to 20%. Obtained conjugate PSMA-DOC is a good candidate for further expanded preclinical trials because of high antitumor activity, fewer side toxic effects and better solubility.

Polysorbate-Based Drug Formulations for Brain-Targeted Drug Delivery and Anticancer Therapy

Polysorbates (PSs) are synthetic nonionic surfactants consisting of polyethoxy sorbitan fatty acid esters. PSs have been widely employed as emulsifiers and stabilizers in various drug formulations and food additives. Recently, various PS-based formulations have been developed for safe and efficient drug delivery. This review introduces the general features of PSs and PS-based drug carriers, summarizes recent progress in the development of PS-based drug formulations, and discusses the physicochemical properties, biological safety, P-glycoprotein inhibitory properties, and therapeutic applications of PS-based drug formulations. Additionally, recent advances in brain-targeted drug delivery using PS-based drug formulations have been highlighted. This review will help researchers understand the potential of PSs as effective drug formulation agents.

The miRNAs involved in prostate cancer chemotherapy response as chemoresistance and chemosensitivity predictors

BACKGROUND

Reliable molecular markers that allow the rational prescription of an effective chemotherapy type for each prostate cancer patient are still needed. Since microRNAs expression is associated with the response to different types of prostate cancer therapy, microRNAs represent a pool of perspective markers of therapy effectiveness comprising chemotherapy.

OBJECTIVES

The available data on microRNAs associated with chemotherapy response (resistance and sensitivity) are summarized and analyzed in the article.

MATERIALS AND METHODS

A review of the published data, as well as their analysis by current bioinformatics resources, was conducted. The molecular targets of microRNAs, as well as the reciprocal relationships between the microRNAs and their targets, were studied using the DIANA, STRING, and TransmiR databases. Special attention was dedicated to the mechanisms of prostate cancer chemoresistance development.

RESULTS AND DISCUSSION

The combined analysis of bioinformatics resources and the available literature indicated that the expression of eight microRNAs that are associated with different responses to chemotherapy have a high potential for the prediction of the prostate cancer chemotherapy response, as found in the experiments and confirmed by the functions of regulated genes.

CONCLUSION

An overview on the published data and bioinformatics resources, with respect to predictive microRNA markers of chemotherapy response, is presented in this review. The selected microRNA and gene panel has a high potential for predicting the chemosensitivity or chemoresistance of prostate cancer and could represent a set of markers for subsequent study using samples of cell-free microRNAs from different patient groups.

Differences between the quality aspects of various generic and branded docetaxel formulations

Docetaxel is a widely prescribed chemotherapy drug in oncology and post expiry of its patent, the drug has been marketed as a generic by multiple manufacturers. It is also classified as a narrow therapeutic window drug. Through enhanced permeability and retention effect, polymeric micelles can passively target agents to tumor tissue, thereby decreasing toxicity of the drug in normal tissue. However, various studies have raised concerns that generic docetaxel leads to greater incidences of toxicities among patients with cancer. Thus, we herein review the pharmaceutical challenges associated with different docetaxel formulations and provide insights into the dissimilarities in the quality and safety of branded and generic docetaxel formulations. Literature review reported that 90% of the generic formulations of docetaxel contain inadequate quantity of active drug and high levels of impurities. Higher amounts of solvents such as polysorbate 80 and ethanol in docetaxel formulation lead to severe toxicities such as febrile neutropenia, hematological, and cutaneous toxicities. In most of the studies, even minor changes in excipients, solvents, unbound fraction of docetaxel were associated with adverse events, while in few, the source of docetaxel remained unidentified. One study reported incidence of febrile neutropenia due to a switch in the formulation from branded to generic. The quality, safety, and efficacy of medicines will directly affect the life of patients, and therefore, use of docetaxel formulations that guarantee safety of patients are the necessity of the hour. Being an injectable anti-cancer drug, it is important to determine the consistency of the various formulations of docetaxel globally, conduct bioequivalence studies as per the regulatory standards, taking into account the permissible limits of the excipients or the presence of such unapproved excipients.

Triple Negative Breast Cancer: A Mountain Yet to Be Scaled Despite the Triumphs

Metastatic progression and tumor recurrence pertaining to TNBC are certainly the leading cause of breast cancer-related mortality; however, the mechanisms underlying TNBC chemoresistance, metastasis, and tumor relapse remain somewhat ambiguous. TNBCs show 77% of the overall 4-year survival rate compared to other breast cancer subtypes (82.7 to 92.5%). TNBC is the most aggressive subtype of breast cancer, with chemotherapy being the major approved treatment strategy. Activation of ABC transporters and DNA damage response genes alongside an enrichment of cancer stem cells and metabolic reprogramming upon chemotherapy contribute to the selection of chemoresistant cells, majorly responsible for the failure of anti-chemotherapeutic regime. These selected chemoresistant cells further lead to distant metastasis and tumor relapse. The present review discusses the approved standard of care and targetable molecular mechanisms in chemoresistance and provides a comprehensive update regarding the recent advances in TNBC management.

Docetaxel encapsulation in nanoscale assembly micelles of folate-PEG-docetaxel conjugates for targeted fighting against metastatic breast cancer in vitro and in vivo

Due to the high frequency and mortality of breast cancer, developing efficient targeted drug delivery systems for frightening against this malignancy is among cancer research priorities. The aim of this study was to synthesize a targeted micellar formulation of docetaxel (DTX) using DTX, folic acid (FA) and polyethylene glycol (PEG) conjugates as building blocks. In the current study, two therapeutic polymers consisting of FA-PEG-DTX and PEG-DTX conjugates were synthesized and implemented to form folate-targeted and non-targeted micelles. Dissipative particle dynamics (DPD) method was used to simulate the behavior of the nanoparticle. The anti-cancer drug, DTX was loaded in to the micelles via solvent switching method in order to increase its solubility and stability. The cytotoxicity of the targeted and non-targeted formulations was evaluated against 4T1 and CHO cell lines. In vivo therapeutic efficiency was studied using ectopic tumor model of metastatic breast cancer, 4T1, in Female BALB/c mice. The successful synthesis of therapeutic polymers, FA-PEG-DTX and PEG-DTX were confirmed implementing ¹HNMR spectral analysis. The size of DTX-loaded non-targeted and targeted micelles were 176.3 ± 8.3 and 181 ± 10.1 nm with PDI of 0.23 and 0.17, respectively. Loading efficiencies of DTX in non-targeted and targeted micelles were obtained to be 85% and 82%, respectively. In vitro release study at pH = 7.4 and pH = 5.4 showed a controlled and continuous drug release for both formulations, that was faster at pH = 5.4 (100% drug release within 120 h) than at pH = 7.4 (80% drug release within 150 h). The targeted formulation showed a significant higher cytotoxicity against 4T1 breast cancer cells (high expression of folate receptor) within the range of 12.5 to 200 μg/mL in comparison with no-targeted one. However, there was no significant difference between the cytotoxicity of the targeted and non-targeted formulations against CHO cell line as low-expressed cell line. In accordance with in vitro investigation, in vivo studies verified the ideal anti-tumor efficacy of the targeted formulation compared to Taxotere and non-targeted formulation. Based on the obtained data, FA-targeted DTX-loaded nano-micelles significantly increased the therapeutic efficacy of DTX and therefore can be considered as a new potent platform for breast cancer chemotherapy.

Tongue conservation treatment for oral tongue squamous cell carcinoma with induction chemotherapy, surgery, and risk-adapted adjuvant therapy: A phase II trial

BACKGROUND

To assess the feasibility of tongue conservation treatment with induction chemotherapy (ICT), tongue conservation surgery, and risk-adapted postoperative adjuvant therapy in oral tongue squamous cell carcinoma (OTSCC).

METHODS

Patients with newly diagnosed OTSCC cT2-4 N0-2 M0 were recruited. The ICT with a regimen of docetaxel, cisplatin, and oral tegafur/uracil (DCU) was administrated every 21 days. After the first cycle of ICT (DCU1), patients with a more than 30% decrease in the longest diameter of primary tumor underwent a second cycle of ICT (DCU2). Tongue conservation surgery was performed after ICT, and risk-adapted adjuvant therapy was organized based on pathological features.

RESULTS

From July 2011 to December 2015, a total of 23 patients were enrolled, 87% of whom were classified as stage III-IV. Clinical responders to DCU1 and DCU2 were determined in 90.5% (19/21) and 88.2% (15/17) of patients. Tongue conservation surgery was performed in 16 responders to ICT. Only one patient had a positive margin (6.3%), and a complete pathologic response was achieved in eight patients (50%). Only one patient developed local recurrence after a median follow-up of 58.6 months (range, 7.9-105.2). The 5-year overall survival (0% vs. 87.5%, P = 0.001) and disease-specific survival (0% vs. 93.3%, P = 0.000) were significantly different between the DCU1 nonresponders and responders.

CONCLUSION

Tongue conservation treatment with ICT, followed by conservation surgery and risk-adapted adjuvant therapy, is feasible for patients with OTSCC who are good responders to ICT. However, the outcomes of nonresponders are dismal. Further study in a larger patient population is warranted.

Identification of Docetaxel as a Potential Drug to Promote HDL Biogenesis

Objective: Our recent studies showed that desmocollin 1 (DSC1) binds to apoA-I in order to inhibit apoA-I-mediated high density lipoprotein (HDL) biogenesis in atherosclerotic plaques. To promote HDL biogenesis in the plaque, here we search for small molecules that block apoA-I-DSC1 interactions. Approach and Results: We combined mutational and computational mapping methods to show that amino acid residues 442-539 in the mature DSC1 protein form an apoA-I binding site (AIBS). Using a crystal structure of the AIBS, we carried out virtual screening of 10 million small molecules to estimate their binding affinities to the AIBS, followed by the selection of 51 high-affinity binding molecules as potential inhibitors of apoA-I-DSC1 interactions. Among the 51, the chemotherapy drug docetaxel showed the highest potency in promoting apoA-I-mediated HDL biogenesis in primary human skin fibroblasts with the half-maximal effective concentration of 0.72 nM. In silico docking studies suggest that the taxane ring in docetaxel binds to the AIBS and that the carbon-13 sidechain of the taxane tightens/stabilizes the binding. The HDL biogenic effect of docetaxel was also observed in two predominant cell types in atherosclerosis, macrophages and smooth muscle cells. Importantly, docetaxel promoted HDL biogenesis at concentrations much lower than those required for inducing cytotoxicity. Conclusion: Determination of the AIBS in DSC1 and AIBS structure-based virtual screening allowed us to identify docetaxel as a strong HDL biogenic agent. With the remarkable potency in promoting HDL biogenesis, a chemotherapy drug docetaxel may be repurposed to enhance atheroprotective HDL functions.

Optimum multi-drug regime for compartment model of tumour: cell-cycle-specific dynamics in the presence of resistance

This work is focused on multi-objective optimisation of a multi-drug chemotherapy schedule for cell-cycle-specific cancer treatment under the influence of drug resistance. The acquired drug resistance to chemotherapeutic agents is incorporated into the existing compartmental model of breast cancer. Furthermore, the toxic effect of drugs on healthy cells and overall drug concentration in the patient body are also constrained in the proposed model. The objective is to determine the optimal drug schedule according to the patient's physiological condition so that the tumour burden is minimised. A multi-objective optimisation algorithm, non-dominated sorting genetic algorithm-II (NSGA-II) is utilised to solve the problem. The obtained results are thoroughly analysed to illustrate the impact of drug resistance on the treatment. The capability of optimised schedules to deal with parametric uncertainty is also analysed. The drug schedules obtained in this work align well with the clinical standards. It is also revealed that the NSGA-II optimised drug schedule with proper rest period between successive dosages yields the minimum cancer load at the end of the treatment.

Prognostic Impact of Sphingosine Kinase 1 in Nonsmall Cell Lung Cancer

Bioactive sphingolipid is clearly relevant to lung physiology. The relationship of the bioactive sphingolipid pathway to pulmonary disease has been studied in cellular, tissue, and animal model, including lung cancer models. The samples of 53 patients diagnosed with nonsmall cell lung carcinoma (NSCLC) between June 2009 and May 2014 at our hospital were analyzed. Immunohistochemical (IHC) analysis was performed. The degree of immunostaining was reviewed and scored. Using this method of assessment, we evaluated the IHC score of sphingosine kinase 1 (SPHK1), vimentin, E-cadherin, and Ki-67. Both invasive adenocarcinoma cell and squamous cell carcinoma cell were well stained by SPHK1, and fibroblasts were also well stained by SPHK1. Although the IHC score of SPHK1 was not significantly differed between invasive adenocarcinoma and squamous cell carcinoma, the IHC scores of fibroblast, vimentin, and Ki-67 were higher in squamous cell carcinoma than invasive adenocarcinoma. Correlation among IHC scores in each of invasive adenocarcinoma and squamous cell carcinoma was performed. SPHK1 had positive correlation with both fibroblast and Ki-67, and fibroblast and Ki-67 had also positive correlation in invasive adenocarcinoma. On the contrary, SPHK1 had no significant correlation with fibroblast, and had negative correlation with Ki-67 in squamous cell carcinoma. Although there was not significant prognostic difference in SPHK1 score (P = .09), IHC score high group tended to be worse on relapse-free survival. SPHK1 might be prognostic factor in lung-invasive adenocarcinoma and novel target for drug against lung-invasive adenocarcinoma.

Abdulbaqi I, Parumasivam T, Mohtar N, A. Wahab H. Advances in Nanocarriers for Effective Delivery of Docetaxel in the Treatment of Lung Cancer: An Overview

Docetaxel (DCX) is a highly effective chemotherapeutic drug used in the treatment of different types of cancer, including non-small cell lung cancer (NSCLC). The drug is known to have low oral bioavailability due to its low aqueous solubility, poor membrane permeability and susceptibility to hepatic first-pass metabolism. To mitigate these problems, DCX is administered via the intravenous route. Currently, DCX is commercially available as a single vial that contains polysorbate 80 and ethanol to solubilize the poorly soluble drug. However, this formulation causes short- and long-term side effects, including hypersensitivity, febrile neutropenia, fatigue, fluid retention, and peripheral neuropathy. DCX is also a substrate to the drug efflux pump P-glycoprotein (P-gp) that would reduce its concentration within the vicinity of the cells and lead to the development of drug resistance. Hence, the incorporation of DCX into various nanocarrier systems has garnered a significant amount of attention in recent years to overcome these drawbacks. The surfaces of these drug-delivery systems indeed can be functionalized by modification with different ligands for smart targeting towards cancerous cells. This article provides an overview of the latest nanotechnological approaches and the delivery systems that were developed for passive and active delivery of DCX via different routes of administration for the treatment of lung cancer.

Role of TDM-based dose adjustments for taxane anticancer drugs

The classical taxanes (paclitaxel, docetaxel), the newer taxane cabazitaxel and the nanoparticle-bound nab-paclitaxel are among the most widely used anticancer drugs. Still, the optimal use and the value of pharmacological personalization of the taxanes is still controversial. We give an overview on the pharmacological properties of the taxanes, including metabolism, pharmacokinetics-pharmacodynamic relations and aspects in the clinical use of taxanes. The latter includes the ongoing debate on the most effective and safe regimen, the recommended initial dose, and pharmacological dosing individualization. The taxanes are among the most widely used anticancer drugs in patients with solid malignancies. Despite their longtime use in clinical routine, the optimal dosing strategy (weekly versus 3-weekly) or optimal average dose (cabazitaxel, nab-paclitaxel) has not been fully resolved, as it may differ according to tumour entity and line of treatment. The value of pharmacological individualization of the taxanes (TDM, TCI) has been partly explored for 3-weekly paclitaxel and docetaxel, but remains mostly unexplored for cabazitaxel and nab-paclitaxel at present.

Association of plasma docetaxel levels with ABCB1 gene polymorphisms and tumour response in locally advanced breast cancer patients of South India on neo-adjuvant chemotherapy

BACKGROUND

Genetic factors could be attributed to the variability in docetaxel plasma levels and its subsequent therapeutic response. The objectives of this study were to assess the effect of ABCB1 gene polymorphisms [SNPs rs1045642 (C3435T) and rs1128503 (C1236T)] on docetaxel plasma levels and also to analyze the influence of docetaxel plasma levels on tumour response in the ethnically distinct South Indian population.

METHODS

104 locally advanced breast cancer (LABC) patients on docetaxel-based neo-adjuvant chemotherapy (NACT) were included. The plasma docetaxel levels were estimated using the validated reverse phase liquid chromatography with mass spectrometry (LC-MS/MS). DNA was extracted (phenol-chloroform extraction method) and the real-time PCR system using validated TaqMan® SNP genotyping assay method was used for genotyping. Tumour response was assessed by RECIST criteria based on the MRI images.

RESULTS

Patients with "CT/TT" genotype of the SNP C1236T had a C₀/C_t ratio of 1.6 times higher than those with "CC" genotype (13.5 ± 6.5 vs 8.3 ± 3.1, p = 0.002). Though not significant, patients with "CT/TT" genotype had greater initial plasma concentration (C₀) and area under the plasma concentration-time curve (AUC_0-t). Conversely, the SNP C3435T was not associated with the plasma docetaxel levels. Furthermore, the C₀ and normalized C₀ were found to be higher in tumour responders compared to non-responders (p < 0.05).

CONCLUSIONS

The plasma levels of docetaxel were significantly influenced by the SNP C1236T of ABCB1 gene coding for the MDR1 transporter (P-glycoprotein). The plasma levels of docetaxel were also found to influence its therapeutic effect.