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1.
Recent Research Progress in Taxol Biosynthetic Pathway and Acylation Reactions Mediated by Taxus Acyltransferases.
Wang, T, Li, L, Zhuang, W, Zhang, F, Shu, X, Wang, N, Wang, Z
Molecules (Basel, Switzerland). 2021;(10)
Abstract
Taxol is one of the most effective anticancer drugs in the world that is widely used in the treatments of breast, lung and ovarian cancer. The elucidation of the taxol biosynthetic pathway is the key to solve the problem of taxol supply. So far, the taxol biosynthetic pathway has been reported to require an estimated 20 steps of enzymatic reactions, and sixteen enzymes involved in the taxol pathway have been well characterized, including a novel taxane-10β-hydroxylase (T10βOH) and a newly putative β-phenylalanyl-CoA ligase (PCL). Moreover, the source and formation of the taxane core and the details of the downstream synthetic pathway have been basically depicted, while the modification of the core taxane skeleton has not been fully reported, mainly concerning the developments from diol intermediates to 2-debenzoyltaxane. The acylation reaction mediated by specialized Taxus BAHD family acyltransferases (ACTs) is recognized as one of the most important steps in the modification of core taxane skeleton that contribute to the increase of taxol yield. Recently, the influence of acylation on the functional and structural diversity of taxanes has also been continuously revealed. This review summarizes the latest research advances of the taxol biosynthetic pathway and systematically discusses the acylation reactions supported by Taxus ACTs. The underlying mechanism could improve the understanding of taxol biosynthesis, and provide a theoretical basis for the mass production of taxol.
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2.
A Compressive Review about Taxol®: History and Future Challenges.
Gallego-Jara, J, Lozano-Terol, G, Sola-Martínez, RA, Cánovas-Díaz, M, de Diego Puente, T
Molecules (Basel, Switzerland). 2020;(24)
Abstract
Taxol®, which is also known as paclitaxel, is a chemotherapeutic agent widely used to treat different cancers. Since the discovery of its antitumoral activity, Taxol® has been used to treat over one million patients, making it one of the most widely employed antitumoral drugs. Taxol® was the first microtubule targeting agent described in the literature, with its main mechanism of action consisting of the disruption of microtubule dynamics, thus inducing mitotic arrest and cell death. However, secondary mechanisms for achieving apoptosis have also been demonstrated. Despite its wide use, Taxol® has certain disadvantages. The main challenges facing Taxol® are the need to find an environmentally sustainable production method based on the use of microorganisms, increase its bioavailability without exerting adverse effects on the health of patients and minimize the resistance presented by a high percentage of cells treated with paclitaxel. This review details, in a succinct manner, the main aspects of this important drug, from its discovery to the present day. We highlight the main challenges that must be faced in the coming years, in order to increase the effectiveness of Taxol® as an anticancer agent.
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3.
Mortality Not Correlated With Paclitaxel Exposure: An Independent Patient-Level Meta-Analysis of a Drug-Coated Balloon.
Schneider, PA, Laird, JR, Doros, G, Gao, Q, Ansel, G, Brodmann, M, Micari, A, Shishehbor, MH, Tepe, G, Zeller, T
Journal of the American College of Cardiology. 2019;(20):2550-2563
Abstract
BACKGROUND Five years of prospective clinical trials confirm that the paclitaxel drug-coated balloon (DCB) (IN.PACT Admiral, Medtronic, Dublin, Ireland) is safe and effective to treat femoropopliteal artery disease. A recent meta-analysis of heterogeneous trials of paclitaxel-based balloons and stents reported that they are associated with increased mortality and that higher doses are linked to higher mortality from 2 to 5 years. OBJECTIVES The purpose of this study was to determine if there is a correlation between paclitaxel exposure and mortality by conducting an independent patient-level meta-analysis of 1,980 patients with up to 5-year follow-up. METHODS Data from 2 single-arm and 2 randomized independently adjudicated prospective studies of a paclitaxel DCB (n = 1,837) and uncoated percutaneous transluminal angioplasty (PTA) (n = 143) were included. Analyses of baseline, procedure, and follow-up data of individual patients were performed to explore correlations of paclitaxel dose with long-term mortality. Survival time by paclitaxel dose tercile was analyzed with adjustment of inverse probability weighting to correct baseline imbalances and study as random effect. A standard cohort was defined to compare DCB- and PTA-treated patients with similar characteristics by applying criteria from pivotal studies (n = 712 DCB, n = 143 PTA). RESULTS A survival analysis stratified nominal paclitaxel dose by low, mid, and upper terciles; mean doses were 5,019.0, 10,007.5, and 19,978.2 μg, respectively. Rates of freedom from all-cause mortality between the 3 groups through 5 years were 85.8%, 84.2%, and 88.2%, respectively (p = 0.731). There was no significant difference in all-cause mortality between DCB and PTA through 5 years comparing all patients (unadjusted p = 0.092) or patients with similar characteristics (adjusted p = 0.188). CONCLUSIONS This independent patient-level meta-analysis demonstrates that this paclitaxel DCB is safe. Within DCB patients, there was no correlation between level of paclitaxel exposure and mortality. (Randomized Trial of IN.PACT Admiral® Drug Coated Balloon vs Standard PTA for the Treatment of SFA and Proximal Popliteal Arterial Disease [INPACT SFA I], NCT01175850; IN.PACT Admiral Drug-Coated Balloon vs. Standard Balloon Angioplasty for the Treatment of Superficial Femoral Artery [SFA] and Proximal Popliteal Artery [PPA] [INPACT SFA II], NCT01566461; MDT-2113 Drug-Eluting Balloon vs. Standard PTA for the Treatment of Atherosclerotic Lesions in the Superficial Femoral Artery and/or Proximal Popliteal Artery [MDT-2113 SFA], NCT01947478; The IN.PACT SFA Clinical Study for the Treatment of Atherosclerotic Lesions in the Superficial Femoral Artery and/or Proximal Popliteal Artery Using the IN.PACT Admiral™ Drug-Eluting Balloon in a Chinese Patient Population, NCT02118532; and IN.PACT Global Clinical Study, NCT01609296).
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4.
[New progress in the treatment of locally advance pancreatic cancer].
de Santibañes, M, Sanchez Clariá, R, de Santibañes, E, Pekolj, J, Mazza, O
Medicina. 2019;(Spec 6/1):576-581
Abstract
Locally advanced pancreatic cancer (LAPC) has several definitions, but it is essentially a non-metastatic tumor, in which the initial surgical resection is not considered beneficial due to the extensive vascular involvement and consequent high chance of a nonradical resection. The introduction of chemotherapy with calcium leucovorin, fluorouracil, irinotecan hydrochloride and oxaliplatin (FOLFIRINOX) and gemcitabine-nab (nanoparticle albumin-bound)-paclitaxel (gem-nab) had very important implications for the management of patients with LAPC. After 4 to 6 months of induction chemotherapy, a large proportion of them have stable disease or even tumor regression, allowing to rescue those who initially were not candidates for surgery, with 30-35 months overall survival after surgery.
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5.
Paclitaxel's Mechanistic and Clinical Effects on Breast Cancer.
Abu Samaan, TM, Samec, M, Liskova, A, Kubatka, P, Büsselberg, D
Biomolecules. 2019;(12)
Abstract
Paclitaxel (PTX), the most widely used anticancer drug, is applied for the treatment of various types of malignant diseases. Mechanisms of PTX action represent several ways in which PTX affects cellular processes resulting in programmed cell death. PTX is frequently used as the first-line treatment drug in breast cancer (BC). Unfortunately, the resistance of BC to PTX treatment is a great obstacle in clinical applications and one of the major causes of death associated with treatment failure. Factors contributing to PTX resistance, such as ABC transporters, microRNAs (miRNAs), or mutations in certain genes, along with side effects of PTX including peripheral neuropathy or hypersensitivity associated with the vehicle used to overcome its poor solubility, are responsible for intensive research concerning the use of PTX in preclinical and clinical studies. Novelties such as albumin-bound PTX (nab-PTX) demonstrate a progressive approach leading to higher efficiency and decreased risk of side effects after drug administration. Moreover, PTX nanoparticles for targeted treatment of BC promise a stable and efficient therapeutic intervention. Here, we summarize current research focused on PTX, its evaluations in preclinical research and application clinical practice as well as the perspective of the drug for future implication in BC therapy.
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6.
Harnessing the Immune System in Pancreatic Cancer.
Das, S, Berlin, J, Cardin, D
Current treatment options in oncology. 2018;(10):48
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Abstract
Managing patients with metastatic pancreatic adenocarcinoma (mPDA) is a challenging proposition for any treating oncologist. Although the potency of first-line therapies has improved with the approvals of FOLFIRINOX and gemcitabine plus nab-paclitaxel, many patients are unable to derive significant benefit from later lines of therapy upon progression. Enrollment on clinical trials remains among the best options for patients with mPDA in all lines of therapy. At our institution, we routinely check for microsatellite instability (MSI-H) and perform next-generation sequencing (NGS) at the time of diagnosis in all good performance status mPDA patients. Although MSI-H status is only found in 1% of patients with mPDA, given pembrolizumab's tissue-agnostic approval for MSI-H tumors in later-line settings, it is a viable option when deciding on subsequent lines of therapy. Any use of immune therapy in mPDA is investigational outside the MSI-H setting. NGS can identify BRCA or other DNA damage response (DDR) defects in patients which can predict sensitivity to platinum-based therapies and influence choice of both initial and later lines of therapy. It can also identify rare actionable genomic alterations such as HER2 (2%) and TRK fusions (0.1%) and offer patients the option of enrollment on clinical trials with agents targeting these or other identified alterations. We believe enrolling mPDA patients on clinical trials with immune-modulating agents is critical to determine if there are other patient subsets, outside of the MSI-H setting, who would benefit from these approaches. Immunotherapy's general tolerability and potential to generate durable responses make it particularly appealing for mPDA patients. Although single-modality immunotherapy such as checkpoint inhibitors or vaccines have not demonstrated efficacy in this disease, combinatorial strategies targeting unique aspects of PDA including the tumor microenvironment and desmoplastic stroma have shown preclinical or early-phase success. Validating these treatments with later-phase prospective studies is essential to making immunotherapy a routine component of the treatment armamentarium for mPDA patients.
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Drug-Coated Balloons for Infrainguinal Peripheral Artery Disease.
Sethi, SS, Lee, MS
The Journal of invasive cardiology. 2016;(7):281-6
Abstract
Revascularization of infrainguinal peripheral artery disease has traditionally been accomplished via percutaneous transluminal angioplasty. However, long-term results have been hampered by high rates of restenosis. Along with the advent of stents, paclitaxel-coated balloons are an emerging therapeutic option for the invasive management of infrainguinal peripheral artery disease. Paclitaxel has been successful in inhibiting neointimal hyperplasia, the main mechanism for in-stent restenosis. Technological advances have facilitated the development of paclitaxel-coated balloons, which show promise in early trials for femoropopliteal stenosis relative to uncoated balloons. For infrapopliteal stenoses, the data remain scant and conflicted. Therefore, large-scale randomized clinical trials with long-term follow-up evaluating safety and effectiveness between various strategies need to be performed to determine the optimal invasive management strategy for infrainguinal peripheral artery disease.
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Critical appraisal of paclitaxel balloon angioplasty for femoral-popliteal arterial disease.
Herten, M, Torsello, GB, Schönefeld, E, Stahlhoff, S
Vascular health and risk management. 2016;:341-56
Abstract
Peripheral arterial disease, particularly critical limb ischemia, is an area with urgent need for optimized therapies because, to date, vascular interventions often have limited life spans. In spite of initial encouraging technical success after femoropopliteal percutaneous transluminal angioplasty or stenting, postprocedural restenosis remains the major problem. The challenging idea behind the drug-coated balloon (DCB) concept is the biological modification of the injury response after balloon dilatation. Antiproliferative drugs administered via DCBs or drug-eluting stents are able to suppress neointimal hyperplasia, the main cause of restenosis. This article reviews the results of DCB treatments of femoropopliteal and infrapopliteal lesions in comparison to standard angioplasty with uncoated balloons. A systematic literature search was performed in 1) medical journals (ie, MEDLINE), 2) international registers for clinical studies (ie, www.clinicaltrials.gov), and 3) abstracts of scientific sessions. Several controlled randomized trials with follow-up periods of up to 5 years demonstrated the efficacy of paclitaxel -DCB technology. However, calcified lesions seem to affect the efficacy of DCB. Combinations of preconditioning methods with DCBs showed promising results. Although the mechanical abrasion of calcium via atherectomy or laser ablation showed favorable periprocedural results, the long-term impact on restenosis and clinical outcome has to be demonstrated. Major advantages of the DCBs are the rapid delivery of drug at uniform concentrations with a single dose, their efficacy in areas wherein stents have been contraindicated until now (ie, bifurcation, ostial lesions), and in leaving no stent scaffold behind. Reinterventions are easier to perform because DCBs leave no metal behind. Various combinations of DCBs with other treatment modalities may prove to be viable options in future. The follow-up results of clinical studies will evaluate the long-term impact of DCBs.
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nab-Paclitaxel dose and schedule in breast cancer.
Martín, M
Breast cancer research : BCR. 2015;(1):81
Abstract
nab-Paclitaxel is approved for the treatment of metastatic breast cancer on an every-3-week schedule based on positive findings from a pivotal phase III trial in which nab-paclitaxel 260 mg/m(2) every 3 weeks was superior to solvent-based paclitaxel 175 mg/m(2) every 3 weeks for the primary endpoint of overall response rate (33 % vs 19 %; P = 0.001). Subsequently, a number of trials have examined different schedules, doses, and combinations in efforts to optimize nab-paclitaxel-based therapy for metastatic and early-stage breast cancer. The goal of this review is to evaluate the clinical experiences to date with nab-paclitaxel as a single agent or in combination with targeted agents in different treatment settings - with a focus on the feasibility of administration, adverse event profile, and standard efficacy endpoints, such as overall survival, progression-free survival, overall response rate, and pathologic complete response rate. In general, weekly dosing during the first 3 of 4 weeks appears to achieve the best clinical benefit in both the metastatic and early-stage settings. Furthermore, the data suggest that high doses of nab-paclitaxel, such as 150 mg/m(2) during first 3 of 4 weeks or 260 mg/m(2) every 2 weeks, may be more feasible and appropriate for treatment of early-stage disease compared with metastatic disease. Intense regimens of nab-paclitaxel may not be the best treatment approach for unselected patients with metastatic breast cancer, but may suit a subset of patients for whom immediate disease control is required. The growing number of nab-paclitaxel trials in breast cancer will lead to greater refinements in tailoring therapy to patients based on their individual disease and patient characteristics.
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10.
Nab-paclitaxel for metastatic pancreatic cancer: clinical outcomes and potential mechanisms of action.
Al-Batran, SE, Geissler, M, Seufferlein, T, Oettle, H
Oncology research and treatment. 2014;(3):128-34
Abstract
For almost 15 years there has been stagnation in the systemic treatment of patients with pancreatic ductal adenocarcinoma (PDAC). Recently, several developments seem to indicate clinically relevant improvements in the treatment of patients with metastatic disease. One of these developments is the introduction of nanoparticle albumin-bound paclitaxel (nab-paclitaxel) into the firstline treatment of metastatic disease. In this review, underlying preclinical and clinical data are discussed, with a special focus on mechanisms of action, the potential interaction with albumin and calcium-binding matricellular glycoproteins, such as the secreted protein acidic and rich in cysteine (SPARC), as well as the clinical outcome associated with the use of nab-paclitaxel.