Ixabepilone related angiographically silent macular edema.

INTRODUCTION: We present a single-eyed case with a previous diagnosis of breast cancer who had intraretinal cystoid changes associated with the systemic administration of ixabepilone in her only seeing eye. To our best knowledge, this is the first reported case describing this phenomenon related to the ixabepilone administration. CASE DESCRIPTION: A 54-year-old woman with a history of breast cancer was examined due to visual deterioration in her only good left eye. The patient had undergone cataract surgery and lens implantation in her right eye following a childhood accident, but subsequently had developed a refractory glaucoma and lost her right vision. Six cycles of 40 mg/m2 systemic ixabepilone (3-hly intravenous infusion once every 3 weeks) had been administered within the past six months. Her visual decline started two weeks following the last treatment session. She was offered intravitreal anti-vascular endothelial growth factor injection elsewhere. Fluorescein angiogram showed no dye leakage whereas spectral-domain optical coherence tomography demonstrated parafoveal intraretinal cystoid changes. En-face optical coherence tomography revealed petaloid type roundish hyporeflective areas at the level of superficial and deep vascular plexus. Ixabepilone-associated cystoid maculopathy was suspected as she received only ixabepilone for the chemotherapy in the last six months. We thus recommended her not to continue ixabepilone therapy. Ten weeks after the ixabepilone cessation, intraretinal cystoid changes had resolved completely. CONCLUSION: Angiographically silent intraretinal cystoid changes may develop in association with the use of ixabepilone. Referral to an ophthalmologist should be considered for the patients experiencing visual complaints as ixabepilone cessation may lead to visual improvement and avoid unnecessary treatment.

Bioprocessing of Epothilone B from Aspergillus fumigatus under solid state fermentation: Antiproliferative activity, tubulin polymerization and cell cycle analysis.

Epothilone derivatives have been recognized as one of the most powerful anticancer drugs towards solid tumors, for their unique affinity to bind with ß-tubulin microtubule arrays, stabilizing their disassembly, causing cell death. Sornagium cellulosum is the main source for Epothilone, however, the fermentation bioprocessing of this myxobacteria is the main challenge for commercial production of Epothilone. The metabolic biosynthetic potency of epothilone by Aspergillus fumigatus, an endophyte of Catharanthus roseus, raises the hope for commercial epothilone production, for their fast growth rate and feasibility of manipulating their secondary metabolites. Thus, nutritional optimization of A. fumigatus for maximizing their epothilone productivity under solid state fermentation process is the objective. The highest yield of epothilone was obtained by growing A. fumigatus on orange peels under solid state fermentation (2.2 µg/g), bioprocessed by the Plackett-Burman design. The chemical structure of the extracted epothilone was resolved from the HPLC and LC-MS/MS analysis, with molecular mass 507.2 m/z and identical molecular fragmentation pattern of epothilone B of S. cellulosum. The purified A. fumigatus epothilone had a significant activity towards HepG2 (IC50 0.98 µg/ml), Pancl (IC50 1.5 µg/ml), MCF7 (IC50 3.7 µg/ml) and WI38 (IC50 4.6 µg/ml), as well as a strong anti-tubulin polymerization activity (IC50 0.52 µg/ml) compared to Paclitaxel (2.0 µg/ml). The effect of A. fumigatus epothilone on the immigration ability of HepG2 cells was assessed, as revealed from the wound closure of the monolayer cells that was estimated by ~ 63.7 and 72.5%, in response to the sample and doxorubicin, respectively, compared to negative control. From the Annexin V-PI flow cytometry results, a significant shift of the normal cells to the apoptosis was observed in response to A. fumigatus epothilone by ~ 20 folds compared to control cells, with the highest growth arrest of the HepG2 cells at the G0-G1 stage.

Epothilone B loaded in acellular nerve allograft enhanced sciatic nerve regeneration in rats.

BACKGROUND: Epothilone B (EpoB) is a microtubule-stabilizing agent with neuroprotective properties. OBJECTIVES: This study examines the regenerative properties of ANA supplemented with EpoB on a sciatic nerve deficit in male Wistar rats. METHODS: For this purpose, the 10 mm nerve gap was filled with acellular nerve allografts (ANAs) containing EpoB at 0.1, 1, and 10 nM concentrations. The sensorimotor recovery was evaluated up to 16 weeks after the operation. Real-time PCR, histomorphometry analysis, and electrophysiological evaluation were also used to evaluate the process of nerve regeneration. RESULTS: ANA/EpoB (0.1 nM) significantly improved sensorimotor recovery in rats compared to ANA, ANA/EpoB (1 nM), and ANA/EpoB (10 nM) groups. This led to reduced muscle atrophy, improved sciatic functional index, and thermal paw withdrawal reflex latency, indicating nerve regeneration and target organ reinnervation. The electrophysiological and histomorphometry findings also confirmed the ANA/EpoB regenerative properties (0.1 nM). EpoB only enhanced ANA regenerative properties at 0.1 nM, with no therapeutic effects at higher concentrations. CONCLUSION: Totally, we concluded that ANA loaded with 0.1 nM EpoB can effectively reconstruct the transected sciatic nerve in rats, likely by enhancing axonal sprouting and extension.

Development of HPLC Method for Ixabepilone (Oncology Drug) in Bulk and Dosage Form: Quantification of Impurities and Forced Degradation Studies.

The objective of study is to develop a new stability-indicating HPLC method for quantifying ixabepilone degradation products and known process impurities (EPO-2 and Epothilone B) in bulk and injectable dose forms. A gradient stability-indicating RP-HPLC approach was developed to determine the known impurities of ixabepilone in ixabepilone API and ixabepilone for injection. Ixabepilone was subjected to base, acid, oxidation, photolytic and thermal degradations. The gradient approach was used to optimize the mobile phase-A [pH 4.8 acetate buffer (10 mM) and acetonitrile 90:10 v/v] and mobile phase-B [pH 4.8 acetate buffer (10 mM) and acetonitrile 20:80 v/v] of a USP L1 column. A wavelength of 250 nm was chosen based on known impurities and degradation products response, with a 1.0 mL/min flow rate. In compliance with ICH criteria Q2(R1), the developed technique was validated. The stability-indicating-related impurities technique was proven to be appropriate for estimating degrading impurities and known impurities in ixabepilone API and ixabepilone injection.

Tumor selective self-assembled nanomicelles of carbohydrate-epothilone B conjugate for targeted chemotherapy.

Epothilone B (Epo B) is a potent antitumor natural product with sub-nanomolar anti-proliferation action against several human cancer cells. However, poor selectivity to tumor cells and unacceptable therapeutic windows of Epo B and its analogs are the major obstacles to their development into clinical drugs. Herein, we present self-assembled nanomicelles based on an amphiphilic carbohydrate-Epo B conjugate that is inactive until converted to active Epo B within the tumor. Four Epo B-Rhamnose conjugates linked via two linkers containing a disulfide bond that is sensitive to GSH were synthesized. Conjugate 34 can self-assemble into nanomicelles with a high concentration of Rha on the surface, allowing for better tumor targeting. After internalization by cancer cells, the disulfide bond can be cleaved in the presence of high levels of GSH to release active Epo B, thereby exhibiting significant anticancer efficiency and selectivity in vitro and in vivo.

Epothilones as Natural Compounds for Novel Anticancer Drugs Development.

Epothilone is a natural 16-membered macrolide cytotoxic compound produced by the metabolism of the cellulose-degrading myxobacterium Sorangium cellulosum. This review summarizes results in the study of epothilones against cancer with preclinical results and clinical studies from 2010-2022. Epothilone have mechanisms of action similar to paclitaxel by inducing tubulin polymerization and apoptosis with low susceptibility to tumor resistance mechanisms. It is active against refractory tumors, being superior to paclitaxel in many respects. Since the discovery of epothilones, several derivatives have been synthesized, and most of them have failed in Phases II and III in clinical trials; however, ixabepilone and utidelone are currently used in clinical practice. There is robust evidence that triple-negative breast cancer (TNBC) treatment improves using ixabepilone plus capecitabine or utidelone in combination with capecitabine. In recent years innovative synthetic strategies resulted in the synthesis of new epothilone derivatives with improved activity against refractory tumors with better activities when compared to ixabepilone or taxol. These compounds together with specific delivery mechanisms could be developed in anti-cancer drugs.

The Improvement of Epothilone D Yield by the Disruption of epoK Gene in Sorangium cellulosum Using TALEN System.

Epothilones are a kind of 16-member macrolides with strong anticancer activity, which was produced by Sorangium cellulosum. Epothlione D shows better drug resistance and safety than taxol in clinical trials. However, the low yield of epothilone D in Sorangium cellulosum and thereof toxicity limited the application of epothilone D. In this study, the epoK gene in gene cluster for epothilone was firstly inactivated by the employment of TALEN gene knockout system. The qRT-PCR analysis and sequencing were performed to confirm the gene deletion of epoK, resulting in the epothilone D yield improvement by 34.9±1.6% and the decrease of epothilone B yield by 34.2±2.5%, which was demonstrated by LC-MS analysis. This study would lay a foundation for the yield improvement of epothilones D, B and thereof derivatives in S. cellulosum by genetic engineering, thus promoting the applications of epothilones in the field of anticancer.

System analysis based on the pyroptosis-related genes identifies GSDMC as a novel therapy target for pancreatic adenocarcinoma.

BACKGROUND: Pancreatic adenocarcinoma (PAAD) is one of the most common malignant tumors of the digestive tract. Pyroptosis is a newly discovered programmed cell death that highly correlated with the prognosis of tumors. However, the prognostic value of pyroptosis in PAAD remains unclear. METHODS: A total of 178 pancreatic cancer PAAD samples and 167 normal samples were obtained from The Cancer Genome Atlas (TCGA) and Genotype-Tissue Expression (GTEx) databases. The "DESeq2" R package was used to identify differntially expressed pyroptosis-related genes between normal pancreatic samples and PAAD samples. The prognostic model was established in TCGA cohort based on univariate Cox and the least absolute shrinkage and selection operator (LASSO) Cox regression analyses, which was validated in test set from Gene Expression Omnibus (GEO) cohort. Univariate independent prognostic analysis and multivariate independent prognostic analysis were used to determine whether the risk score can be used as an independent prognostic factor to predict the clinicopathological features of PAAD patients. A nomogram was used to predict the survival probability of PAAD patients, which could help in clinical decision-making. The R package "pRRophetic" was applied to calculate the drug sensitivity of each samples from high- and low-risk group. Tumor immune infiltration was investigated using an ESTIMATE algorithm. Finally, the pro-tumor phenotype of GSDMC was explored in PANC-1 and CFPAC-1 cells. RESULT: On the basis of univariate Cox and LASSO regression analyses, we constructed a risk model with identified five pyroptosis-related genes (IL18, CASP4, NLRP1, GSDMC, and NLRP2), which was validated in the test set. The PAAD samples were divided into high-risk and low-risk groups on the basis of the risk score's median. According to Kaplan Meier curve analysis, samples from high-risk groups had worse outcomes than those from low-risk groups. The time-dependent receiver operating characteristics (ROC) analysis revealed that the risk model could predict the prognosis of PAAD accurately. A nomogram accompanied by calibration curves was presented for predicting 1-, 2-, and 3-year survival in PAAD patients. More importantly, 4 small molecular compounds (A.443654, PD.173074, Epothilone. B, Lapatinib) were identified, which might be potential drugs for the treatment of PAAD patients. Finally, the depletion of GSDMC inhibits the proliferation, invasion, and migration of pancreatic adenocarcinoma cells. CONCLUSION: In this study, we developed a pyroptosis-related prognostic model based on IL18, CASP4, NLRP1, NLRP2, and GSDMC , which may be helpful for clinicians to make clinical decisions for PAAD patients and provide valuable insights for individualized treatment. Our result suggest that GSDMC may promote the proliferation and migration of PAAD cell lines. These findings may provide new insights into the roles of pyroptosis-related genes in PAAD, and offer  new therapeutic targets for the treatment of PAAD.

Single-cell transcriptomics reveals the role of Macrophage-Naïve CD4 + T cell interaction in the immunosuppressive microenvironment of primary liver carcinoma.

BACKGROUND: Liver carcinoma generally presents as an immunosuppressive microenvironment that promotes tumor evasion. The intercellular crosstalk of immune cells significantly influences the construction of an immunosuppressive microenvironment. This study aimed to investigate the important interactions between immune cells and their targeting drugs in liver carcinoma, by using single-cell and bulk transcriptomic data. METHODS: Single-cell and bulk transcriptomic data were retrieved from Gene Expression Omnibus (GSE159977, GSE136103, and GSE125449) and The Cancer Genome Atlas (TGCA-LIHC), respectively. Quality control, dimension reduction, clustering, and annotation were performed according to the Scanpy workflow based on Python. Cell-cell interactions were explored using the CellPhone database and CellChat. Trajectory analysis was executed using a partition-based graph abstraction method. The transcriptomic factors (TFs) were predicted using single-cell regulatory network inference and clustering (SCENIC). The target genes from TFs were used to establish a related score based on the TCGA cohort; this score was subsequently validated by survival, gene set enrichment, and immune cell infiltration analyses. Drug prediction was performed based on the Cancer Therapeutics Response Portal and PRISM Repurposing datasets. RESULTS: Thirty-one patients at four different states, including health, hepatitis, cirrhosis, and cancer, were enrolled in this study. After dimension reduction and clustering, twenty-two clusters were identified. Cell-cell interaction analyses indicated that macrophage-naive CD4 + T cell interaction significantly affect cancerous state. In brief, macrophages interact with naive CD4 + T cells via different pathways in different states. The results of SCENIC indicated that macrophages present in cancer cells were similar to those present during cirrhosis. A macrophage-naive CD4 + T cell (MNT) score was generated by the SCENIC-derived target genes. Based on the MNT score, five relevant drugs (inhibitor of polo-like kinase 1, inhibitor of kinesin family member 11, dabrafenib, ispinesib, and epothilone-b) were predicted. CONCLUSIONS: This study reveals the crucial role of macrophage-naive CD4 + T cell interaction in the immunosuppressive microenvironment of liver carcinoma. Tumor-associated macrophages may be derived from cirrhosis and can initiate liver carcinoma. Predictive drugs that target the macrophage-naive CD4 + T cell interaction may help to improve the immunosuppressive microenvironment and prevent immune evasion. The relevant mechanisms need to be further validated in experiments and cohort studies.

Preclinical Evaluation of Ixabepilone in Combination with VEGF Receptor and PARP Inhibitors in Taxane-Sensitive and Taxane-Resistant MDA-MB-231 Breast Cancer Cells.

Long-term use of cytotoxic agents promotes drug-resistance in triple-negative breast cancer (TNBC). The identification of new drug combinations with efficacy against drug-resistant TNBC cells in vitro is valuable in developing new clinical strategies to produce further cancer remissions. We undertook combination analysis of the cytotoxic agent ixabepilone with small molecule inhibitors of vascular endothelial growth factor receptor (VEGFR) and poly (ADP-ribose) polymerase (PARP) in taxane-sensitive (231C) and taxane-resistant (TXT) MDA-MB-231-derived cells. As single agents, the VEGFR inhibitors cediranib and bosutinib decreased both 231C and TXT cell viability, but four other VEGFR inhibitors and two PARP inhibitors were less effective. Combinations of ixabepilone with either cediranib or bosutinib synergistically decreased 231C cell viability. However, only the ixabepilone/cediranib combination was synergistic in TXT cells, with predicted 15.3-fold and 1.65-fold clinical dose reductions for ixabepilone and cediranib, respectively. Flow cytometry and immunoblotting were used to further evaluate the loss of cell viability. Thus, TXT cell killing by ixabepilone/cediranib was enhanced over ixabepilone alone, and expression of proapoptotic cleaved caspase-3 and the Bak/Bcl-2 protein ratio were increased. These findings suggest that the synergistic activity of the ixabepilone/cediranib combination in taxane-sensitive and taxane-resistant cells may warrant clinical evaluation in TNBC patients.

[Protective effect of Epothilone D against traumatic optic nerve injury in rats].

OBJECTIVE: To investigate the therapeutic effect of Epothilone D on traumatic optic neuropathy (TON) in rats. METHODS: Forty-two SD rats were randomized to receive intraperitoneal injection of 1.0 mg/kg Epothilone D or DMSO (control) every 3 days until day 28, and rat models of TON were established on the second day after the first administration. On days 3, 7, and 28, examination of flash visual evoked potentials (FVEP), immunofluorescence staining and Western blotting were performed to examine the visual pathway features, number of retinal ganglion cells (RGCs), GAP43 expression level in damaged axons, and changes of Tau and pTau-396/404 in the retina and optic nerve. RESULTS: In Epothilone D treatment group, RGC loss rate was significantly decreased by 19.12% (P=0.032) on day 3 and by 22.67% (P=0.042) on day 28 as compared with the rats in the control group, but FVEP examination failed to show physiological improvement in the visual pathway on day 28 in terms of the relative latency of N2 wave (P=0.236) and relative amplitude attenuation of P2-N2 wave (P=0.441). The total Tau content in the retina of the treatment group was significantly increased compared with that in the control group on day 3 (P < 0.001), showing a consistent change with ptau-396/404 level. In the optic nerve axons, the total Tau level in the treatment group was significantly lower than that in the control group on day 7 (P=0.002), but the changes of the total Tau and pTau-396/404 level did not show an obvious correlation. Epothilone D induced persistent expression of GAP43 in the damaged axons, detectable even on day 28 of the experiment. CONCLUSION: Epothilone D treatment can protect against TON in rats by promoting the survival of injured RGCs, enhancing Tau content in the surviving RGCs, reducing Tau accumulation in injured axons, and stimulating sustained regeneration of axons.

Epothilone D Modulates Autism-like Behaviors in the BTBR Mouse Model of Autism Spectrum Disorder.

Autism spectrum disorder (ASD) is a neurodevelopmental disorder, characterized by impaired social communication, abnormal repetitive behaviors and restricted interests and/or sensory behaviors. It has been widely accepted that ASD involves a complex interplay of both genetic and environmental risk factors. Existing medications are only symptomatic treatments, there are no effective treatments that can improve these core social behavior deficits. Recent studies indicated that synaptic development and abnormal myelination are linked to the pathogenesis of ASD. The stable tubule only polypeptide (STOP) protein, also known as microtubule-associated protein 6, plays an important role in neuronal development and synaptic plasticity. Our previous studies showed that STOP protein was significantly reduced in the plasma of autistic subjects and in the cortex of BTBR T+ Itpr3tf (BTBR) mouse model of ASD. Furthermore, studies have shown that Epothilone D, a taxol-like microtubule-stabilizing agent, could alleviate behavioral and synaptic deficits in STOP-null mice. Here, we further evaluate whether Epothilone D treatment is sufficient to modulate the autism-like behaviors in the BTBR mice, and explore the underlying mechanism. BTBR mice were treated either with Epothilone D dissolved in 99% dimethyl sulfoxide (DMSO) or with 99% DMSO vehicle. Our studies demonstrated that the restricted and repetitive behaviors of BTBR mice were improved after Epothilone D treatment, which could be achieved by improving microtubule stability and further regulating the expression of excitatory synapse-related and myelin-related proteins. These results indicate that microtubule stability may be a new and promising therapeutic target for treating patients with ASD.

Randomised phase II trial of weekly ixabepilone ± biweekly bevacizumab for platinum-resistant or refractory ovarian/fallopian tube/primary peritoneal cancer.

BACKGROUND: This multi-center RP2 study assessed activity/safety of ixabepilone + bevacizumab compared to ixabepilone in platinum-resistant/refractory ovarian/fallopian tube/primary peritoneal cancer. Additional objectives were to examine the role of prior bevacizumab and taxanes, and explore class III-ß-tubulin (TUBB3) as a predictive biomarker. METHODS: Participants were randomised to receive ixabepilone 20 mg/m2 days 1, 8, 15 with (IXA + BEV) or without (IXA) bevacizumab 10 mg/kg days 1, 15 every 28 days. Patients were stratified by prior BEV. The primary endpoint was PFS. OS, safety, and ORR served as secondary endpoints. RESULTS: Among 76 evaluable patients who received IXA + BEV (n = 39) compared to IXA (n = 37), the ORR was 33% (n = 13) versus 8% (n = 3)(P = 0.004), durable at 6 months in 37% (n = 14) and 3% (n = 1) (P < 0.001). BEV significantly improved PFS (median:5.5 vs 2.2 months, HR = 0.33, 95%CI 0.19-0.55, P < 0.001) and OS (median:10.0 vs 6.0 months, HR = 0.52, 95%CI 0.31-0.87, P = 0.006). Both regimens were well-tolerated. TUBB3 expression did not predict response. Subgroup analyses revealed minimal effect of prior BEV or taxane resistant/refractory status on response to IXA + BEV. CONCLUSIONS: IXA + BEV is a well-tolerated, effective combination for platinum/taxane-resistant ovarian cancer that extends PFS and likely OS relative to IXA monotherapy. Prior receipt of BEV should not preclude the use of IXA + BEV. TUBB3 is not a predictive biomarker. CLINICAL TRIAL REGISTRATION: NCT3093155.

Docking-guided rational engineering of a macrolide glycosyltransferase glycodiversifies epothilone B.

Glycosyltransferases typically display acceptor substrate flexibility but more stringent donor specificity. BsGT-1 is a highly effective glycosyltransferase to glycosylate macrolides, including epothilones, promising antitumor compounds. Here, we show that BsGT-1 has three major regions significantly influencing the glycodiversification of epothilone B based on structural molecular docking, "hot spots" alanine scanning, and site saturation mutagenesis. Mutations in the PSPG-like motif region and the C2 loop region are more likely to expand donor preference; mutations of the flexible N3 loop region located at the mouth of the substrate-binding cavity produce novel epothilone oligosaccharides. These "hot spots" also functioned in homologues of BsGT-1. The glycosides showed significantly enhanced water solubility and decreased cytotoxicity, although the glycosyl appendages of epothilone B also reduced drug permeability and attenuated antitumor efficacy. This study laid a foundation for the rational engineering of other GTs to synthesize valuable small molecules.

UPLC-PDA coupled HR-TOF ESI/MS2 -based identification of derivatives produced by whole-cell biotransformation of epothilone A using Nocardia sp. CS692 and a cytochrome P450 overexpressing strain.

Epothilone A, a microtubule-stabilizing agent used as therapeutics for the treatment of cancers, was biotransformed into three metabolites using Nocardia sp. CS692 and recombinant Nocardia overexpressing a cytochrome P450 from Streptomyces venezuelae (PikC). Among three metabolites produced in the biotransformation reaction mixtures, ESI/MS2 analysis predicted two metabolites (M1 and M2) as novel hydroxylated derivatives (M1 is hydroxylated at the C-8 position and M2 is hydroxylated at C-10 position), each with an opened-epoxide ring in their structure. Interestingly, metabolite M3 lacks an epoxide ring and is known as deoxyepothilone A, which is also called epothilone C. Metabolite M1 was produced only in PikC overexpressing strain. The endogenous enzymes of Nocardia sp. catalyzed hydroxylation of epothilone A to produce metabolite M2 and removed epoxide ring to produce metabolite M3. All the metabolites were identified based on UV-vis analysis and rigorous ESI/MS2 fragmentation based on epothilone A standard. The newly produced metabolites are anticipated to display novel cytotoxic effects and could be subjects of further pharmacological studies.

Photoswitchable Epothilone-Based Microtubule Stabilisers Allow GFP-Imaging-Compatible, Optical Control over the Microtubule Cytoskeleton.

Optical methods to modulate microtubule dynamics show promise for reaching the micron- and millisecond-scale resolution needed to decrypt the roles of the cytoskeleton in biology. However, optical microtubule stabilisers are under-developed. We introduce "STEpos" as GFP-orthogonal, light-responsive epothilone-based microtubule stabilisers. They use a novel styrylthiazole photoswitch in a design to modulate hydrogen-bonding and steric effects that control epothilone potency. STEpos photocontrol microtubule dynamics and cell division with micron- and second-scale spatiotemporal precision. They substantially improve potency, solubility, and ease-of-use compared to previous optical microtubule stabilisers, and the structure-photoswitching-activity relationship insights in this work will guide future optimisations. The STEpo reagents can contribute greatly to high-precision research in cytoskeleton biophysics, cargo transport, cell motility, cell division, development, and neuroscience.

Protective effect of Epothilone D against traumatic optic nerve injury in rats / 南方医科大学学报

OBJECTIVE@#To investigate the therapeutic effect of Epothilone D on traumatic optic neuropathy (TON) in rats.@*METHODS@#Forty-two SD rats were randomized to receive intraperitoneal injection of 1.0 mg/kg Epothilone D or DMSO (control) every 3 days until day 28, and rat models of TON were established on the second day after the first administration. On days 3, 7, and 28, examination of flash visual evoked potentials (FVEP), immunofluorescence staining and Western blotting were performed to examine the visual pathway features, number of retinal ganglion cells (RGCs), GAP43 expression level in damaged axons, and changes of Tau and pTau-396/404 in the retina and optic nerve.@*RESULTS@#In Epothilone D treatment group, RGC loss rate was significantly decreased by 19.12% (P=0.032) on day 3 and by 22.67% (P=0.042) on day 28 as compared with the rats in the control group, but FVEP examination failed to show physiological improvement in the visual pathway on day 28 in terms of the relative latency of N2 wave (P=0.236) and relative amplitude attenuation of P2-N2 wave (P=0.441). The total Tau content in the retina of the treatment group was significantly increased compared with that in the control group on day 3 (P < 0.001), showing a consistent change with ptau-396/404 level. In the optic nerve axons, the total Tau level in the treatment group was significantly lower than that in the control group on day 7 (P=0.002), but the changes of the total Tau and pTau-396/404 level did not show an obvious correlation. Epothilone D induced persistent expression of GAP43 in the damaged axons, detectable even on day 28 of the experiment.@*CONCLUSION@#Epothilone D treatment can protect against TON in rats by promoting the survival of injured RGCs, enhancing Tau content in the surviving RGCs, reducing Tau accumulation in injured axons, and stimulating sustained regeneration of axons.

Improving motor neuron-like cell differentiation of hEnSCs by the combination of epothilone B loaded PCL microspheres in optimized 3D collagen hydrogel.

Spinal cord regeneration is limited due to various obstacles and complex pathophysiological events after injury. Combination therapy is one approach that recently garnered attention for spinal cord injury (SCI) recovery. A composite of three-dimensional (3D) collagen hydrogel containing epothilone B (EpoB)-loaded polycaprolactone (PCL) microspheres (2.5 ng/mg, 10 ng/mg, and 40 ng/mg EpoB/PCL) were fabricated and optimized to improve motor neuron (MN) differentiation efficacy of human endometrial stem cells (hEnSCs). The microspheres were characterized using liquid chromatography-mass/mass spectrometry (LC-mas/mas) to assess the drug release and scanning electron microscope (SEM) for morphological assessment. hEnSCs were isolated, then characterized by flow cytometry, and seeded on the optimized 3D composite. Based on cell morphology and proliferation, cross-linked collagen hydrogels with and without 2.5 ng/mg EpoB loaded PCL microspheres were selected as the optimized formulations to compare the effect of EpoB release on MN differentiation. After differentiation, the expression of MN markers was estimated by real-time PCR and immunofluorescence (IF). The collagen hydrogel containing the EpoB group had the highest HB9 and ISL-1 expression and the longest neurite elongation. Providing a 3D permissive environment with EpoB, significantly improves MN-like cell differentiation and maturation of hEnSCs and is a promising approach to replace lost neurons after SCI.

Eficacia y seguridad de ixabepilona para el tratamiento de pacientes con cáncer de mama metastásico resistente a antraciclina, taxanos y capecitabina con estado funcional ECOG 0-1 / Efficacy and safety of ixabepilone for the treatment of patients with metastatic breast cancer resistant to anthracyclines, taxanes and capecitabine with ECOG performance status 0-1

INTRODUCCIÓN: El presente dictamen expone la evaluación de la eficacia y seguridad de ixabepilona, comparado con la mejor terapia de soporte, para el tratamiento de pacientes con cáncer de mama metastásico (CMM) resistente a antraciclinas, taxanos y capecitabina con estado funcional ECOG 0-1. El cáncer de mama es la neoplasia más frecuente en mujeres en todo el mundo. En Perú, el cáncer de mama es la tercera causa de muerte por cáncer, con una tasa de mortalidad estandarizada por edad de 9.1 muertes por cada 100,000 habitantes. El cáncer mama metastásico (CMM) es una condición incurable que ocurre cuando la enfermedad se ha diseminado más allá de la mama y los ganglios linfáticos ipsilaterales hacia otros órganos. Se estima que la tasa de sobrevida global (SG) en pacientes con CMM, hasta los 5 años, es de aproximadamente 27 % con una mediana de SG de dos a tres años. Sin embargo, la esperanza de vida es menor a 1 año en pacientes con CMM que ya han recibido tres líneas de quimioterápicos. Asimismo, el 62 % de las pacientes con CMM tienen afectación visceral (hígado, pulmón o pleura), lo que compromete el funcionamiento normal de los órganos y las pacientes pueden presentar crisis visceral. La quimioterapia, dentro de las terapias sistémicas, es la principal opción terapéutica para la mayoría de las pacientes con CMM. No obstante, en casos muy avanzados de la enfermedad (como el CMM) y/o en casos de resistencia a varias líneas de tratamiento, las opciones terapéuticas que se pueden ofrecer a estas pacientes son escasas. Actualmente, EsSalud dispone de agentes quimioterápicos como: antraciclinas (inhibidor de topoisomerasa II), taxanos (agente anti microtúbulo) y capecitabina (inhibidor de nucleósido metabólico) para el tratamiento de pacientes con CMM. No obstante, ciertos pacientes no responden favorablemente a estos tratamientos. Los especialistas sugieren que ixabepilona puede ser una alternativa de tratamiento para los pacientes con CMM resistente a otros agentes como: antraciclinas, taxanos y capecitabina. METODOLOGÍA: Se llevó a cabo una búsqueda de la literatura científica con el objetivo de identificar la mejor evidencia sobre la eficacia y seguridad de ixabepilona en pacientes con CMM resistente a antraciclinas, taxanos y capecitabina con estado funcional ECOG 0-1. La búsqueda sistemática se realizó en las principales bases de datos PubMed, The Cochrane Library y LILACS. Asimismo, se realizó una búsqueda manual dentro de las bases de datos pertenecientes a grupos que realizan evaluación de tecnologías sanitarias (ETS) y guías de práctica clínica (GPC); incluyendo el National Institute for Health and Care Excellence (NICE), la Canadian Agency for Drugs and Technologies in Health (CADTH), el Scottish Medicines Consortium (SMC), la Scottish Intercollegiate Guidelines Network (SIGN), el Institute for Clinical and Economic Review (ICER), el Institut für Qualität und Wirtschaftlichkeit im Gesundheitswese (IQWiG), la Base Regional de Informes de evaluación de tecnologías en Salud de las Américas (BRISA), la Organización Mundial de la Salud (OMS), el Ministerio de Salud del Perú (MINSA) y el Instituto de Evaluación de Tecnologías en Salud e Investigación (IETSI). Además, se realizó una búsqueda de GPC de las principales sociedades o instituciones especializadas en oncología como National Comprehensive Cancer Network (NCCN), European Society for Medical Oncology (ESMO) y American Society of Clinical Oncology (ASCO). Finalmente, se realizó una búsqueda manual en la página web de registro de EC de ClinicalTrials.gov del National Institutes of Health (https://clinicaltrials.gov/) para identificar EC en curso o de resultados que no hayan sido publicados aún. RESULTADOS: Se llevó a cabo una búsqueda de evidencia científica con respecto al uso de ixabepilona como tratamiento de pacientes con CMM resistente a antraciclinas, taxanos y capecitabina con estado funcional ECOG 0-1. CONCLUSIONES:  El presente dictamen tuvo como objetivo evaluar la mejor evidencia disponible hasta julio de 2021 sobre la eficacia y seguridad de ixabepilona como terapia para pacientes con CMM resistente a antraciclinas, taxanos y capecitabina con ECOG 0-1.  Luego de la búsqueda sistemática, se identificaron dos GPC elaboradas por la NCCN y por la ESO-ESMO y un ensayo clínico de fase II (NCT00080262). Sobre las GPC, la NCCN señala que la mayoría de pacientes serán candidatos a múltiples líneas de terapia sistémica en función de su estado funcional; sin embargo, no especifica el número de líneas tratamiento a brindar. Dentro estos tratamientos señalan algunos como preferentes (antraciclinas, taxanos, capecitabina, gemcitabina y vinorelbina) y a otros como no preferentes (otros quimioterápicos e ixabepilona). La NCCN y la ESO-ESMO recomiendan la terapia paliativa. La NCCN recomienda que se considere no continuar con la terapia sistémica citotóxica y ofrecer la terapia paliativa en paciente con CMM que ha recibido varias líneas de quimioterápicos. La ESO-ESMO recomienda la terapia paliativa en pacientes con CMM cuyo tratamiento activo (e.g. quimioterapia) ya no sea capaz de controlar la enfermedad metastásica y la toxicidad supere los beneficios. El ensayo clínico de fase II, sin grupo control, evaluó el efecto de ixabepilona en la SG y la seguridad en pacientes con CMM resistente a antraciclina, taxanos y capecitabina. Debido al sesgo de reporte de resultados y, principalmente, la falta de grupo control, no se puede establecer una relación causal entre los resultados observados y el tratamiento con ixabepilona. Por lo tanto, no se puede determinar la eficacia comparativa entre ixabepilona y la mejor terapia de soporte que consiste en continuar con el uso de quimioterápicos y brindar cuidado paliativo. La incidencia de EA de grado 4 (34 %), el 11 % de pacientes que descontinuaron el tratamiento y la una muerte asociada al uso de ixabepilona, reportados en el EC fase II, y que fueron el motivo por que cual la EMA no aprobó su uso, sugieren que el perfil de seguridad de ixabepilona no sería favorable. Las evaluaciones de ixabepilona por parte de la EMA y la DIGEMID, basados en el EC fase II, concluyeron que los riesgos de ixabepilona superan sus potenciales beneficios en el tratamiento de pacientes con CMM. Por lo tanto, para estas instituciones tampoco sería seguro el uso de ixabepilona en el subgrupo de pacientes con CMM resistente a antraciclinas, taxanos y capecitabina.  Por lo expuesto, el IETSI no aprueba el uso de ixabepilona para el tratamiento de paciente con cáncer de mama metastásico resistente a antraciclinas, taxanos y capecitabina con estado funcional ECOG 0-1.

Eficacia y seguridad de ixabepilona en el tratamiento médico oncológico del cáncer de mama triple negativo resistente a antraciclinas y taxanos / Efficacy and safety of ixabepilone in the medical oncological treatment of triple negative breast cancer resistant to anthracyclines and taxanes

INTRODUÇÃO: El cáncer de mama es una enfermedad con una alta incidencia y mortalidad a nivel mundial, latinoamericano y en Perú. Se describen cuatro subtipos de cáncer de mama según la expresión o no de cuatro marcadores (receptor de estrógeno, RE; receptor de progesterona, RP; HER2 y Ki67): Luminal, HER2 y triple negativo; representando este último un 21% de los casos según un estudio llevado a cabo en población institucional. - La ixabepilona es un antineoplásico perteneciente al grupo de las epotilonas que se encargan de estabilizar los microtúbulos causando una muerte celular por apoptosis. Es un medicamento que ha sido evaluado en estudios de fase II obteniendo resultados favorables en pacientes con cáncer de mama avanzando y además se han realizado estudios de fase III que avalan su uso en pacientes con cáncer de mama avanzado que han progresado a terapias con antraciclinas y taxanos. METODOLOGÍA: Se decidió realizar un informe de ETS que permita mostrar la eficacia y seguridad de la ixabepilona con capecitabina comparada con capecitabina sola para el tratamiento oncológico de pacientes con cáncer de mama triple negativo resistentes a antraciclinas y taxanos. Se encontró que una GPC internacional (NCCN) avala el uso de ixabepilona en pacientes con cáncer de mama avanzado y el documento institucional también menciona estudios que avalan su utilidad en estos pacientes; sin embargo, la guía de ESMO no menciona su uso lo cual se debe a que EMA no aprobó su incorporación en Europa y que disponen de otras alternativas como eribulina. Además, se encontraron 04 ETS o informes relacionados en los cuales se ha reportado evidencia sobre el uso de ixabepilona en pacientes con cáncer de mama avanzado. DISCUSIÓN: La discusión con el panel se llevó a cabo durante dos sesiones en las cuales se expuso la PICO, la estrategia de búsqueda, las evidencias con respecto a la guías de práctica clínica, informes de evaluación de tecnologías sanitarias y documentos relacionados. Además, los análisis comparativos de eficacia y seguridad así como los análisis de costos de los diferentes medicamentos disponibles para el tratamiento de cáncer de mama avanzado triple negativo. En la primera sesión se comentó que ixabepilona es un tratamiento que se ha estado usando a nivel institucional en monoterapia para el tratamiento de pacientes con cáncer de mama triple negativo localmente avanzado o metastasico que hayan recibido terapia previa incluyendo una antraciclina, un taxano y/o capecitabina. Los casos se aprueban a través de junta médica y se realiza una vigilancia periódica. A la fecha 18 pacientes han recibido el tratamiento. Además, un integrante del panel manifestó que está de acuerdo con la propuesta brindada por el informe de Instituto de Cáncer de Argentina que especifica "No se sugiere el uso rutinario de Ixabepilona como tratamiento en pacientes con CMM RH positivos HER2 negativos, ECOG 0-1 y enfermedad evaluable salvo en pacientes seleccionadas: resistentes a antraciclinas/taxanos sin neuropatía residual significativa, con enfermedad visceral sintomática. (Condicional, moderada)". Se comentó que se tiene conocimiento de los pacientes que están recibiendo el tratamiento y que es un grupo que presentan bajo riesgo de presentar neutropenia o neuropatía periférica. No ha habido reportes adversos serios hasta el momento a nivel institucional con respecto al uso de este medicamento. Se consultó si es que se disponía de otras terapias que puedan ser comparadas con ixabepilona con respecto a eficacia y seguridad de los pacientes con cáncer de mama triple negativo que progresan a antraciclinas y taxanos. Es necesario conocer que estudios existen y poder concluir si es que ixabepilona sería la mejor intervención farmacológica disponible para estos casos específicos de paciente o existiría alguna otra que esté disponible a nivel nacional y que pueda usarse. Durante segunda reunión se mencionó que a nivel internacional se tiene la disponibilidad del medicamento eribulina que ha reportado mejores resultados con respecto a otros tratamientos en el cáncer de mama avanzado triple negativo a nivel nacional pero no se cuenta con disponibilidad de este medicamento a nivel nacional además que los costos son muy elevados por ello se mencionó que es una necesidad que se continúe con la disponibilidad de este medicamento. Además, en base a lo reportado a nivel institucional se mencionó que es necesario ser más específico en la indicación y los pacientes a los cuales se les va a prescribir el medicamento. Además, ppdría considerarse que Ixabepilona asociado a Capecitabina podría ser utilizado en población mejor seleccionada: ECOG 0 ­ 1, expuestos a antraciclinas y taxanos, que no hayan sido expuesto a capecitabina, donde se haya descartado metástasis cerebral previa al inicio del tratamiento y en pacientes con sospecha de mutación BRCA ofrecerles terapia con sales de platino. Con respecto a la evidencia en supervivencia global, supervivencia libre de progresión, tasa de respuesta objetiva de otras intervenciones farmacológicas se encuentran valores similares a los reportados por ixabepilona. Con respecto al tratamiento brindado a los 11 pacientes a nivel institucional no se ha podido establecer beneficios: tres de 11 pacientes han fallecido, no se ha documentado algún tipo de respuesta parcial. Por otro lado, se mencionó que en base a lo reportado es difícil proponer continuar con la adquisición del medicamento ya que no ha demostrado superioridad en supervivencia global y que no se cuenta con estudios de evaluaciones económicas o análisis de impacto presupuestario que avalen contar con el medicamento además que el costo adicional que implica la prescripción del medicamento es elevado. Se mencionó que al actualmente el SIS no viene cubriendo todos los medicamentos no PNUME, por lo que solicita se considere un tratamiento alterno a Ixabepilona que si se encuentre disponible en la lista PNUME. CONCLUSIONES: En el Instituto Nacional de Enfermedades Neoplásicas (INEN) en base a la información del departamento de oncología médica se han proyectado de maneral anual un promedio de 18 a 35 casos de pacientes con cáncer de mama triple negativo resistentes a antraciclinas y taxanos. Se realizó una búsqueda sistemática y una búsqueda dirigida de la evidencia para evaluar la eficacia y seguridad del uso de ixabepilona con capecitabina comparado con capecitabina sola para el tratamiento médico oncológico de pacientes con cáncer de mama triple negativo resistente a antraciclinas y taxanos. Se incluyó 02 guías de práctica clínica internacionales y un documento técnico institucional, 05 evaluaciones de tecnologías sanitarias o informes relacionados y un estudio de análisis combinado de dos ensayos clínicos que analiza a ixabepilona en monodroga comparado con la combinación de ixabepilona con capecitabina. Adicionalmente, se han incluido 05 estudios de otras opciones terapéuticas disponibles para el tratamiento de cáncer de mama avanzado triple negativo. En las GPC; en una se menciona el uso de ixabepilona en el manejo de cáncer de mama avanzado, en otra GPC no se establece una recomendación pero si colocan otras opciones como capecitabina, gemcitabina, etc; y en el documento institucional se la menciona pero no se especifican recomendaciones dentro del grupo de cáncer de mama triple negativo resistente a antraciclinas y taxanos. n las 04 ETS. Se menciona que en los países donde está permitida su comercialización, su uso se permite para pacientes con características específicas siendo la ETS Argentina la que emite una recomendación débil en contra sobre su uso y reserva el uso de ixabepilona en pacientes con cáncer de mama avanzado con características específicas de manera excepcional. El estudio de Rugo que combina los datos reportados en 02 ensayos clínicos de fase III ha encontrado un aumento en la supervivencia libre de progresión en el grupo de ixabepilona más capecitabina y duplicación en la tasa de respuesta objetivo; sin embargo, no se encontró aumento en el desenlace crítico supervivencia global ni en calidad de vida, encontrándose también un aumento en la frecuencia de eventos adversos relacionados a toxicidad por la terapia combina, neutropenia y neuropatías periféricas. La calidad de evidencia global fue moderada. Con respecto a lo evidenciado por otros medicamentos en pacientes con cáncer de mama avanzado triple negativo resistentes a antraciclinas y/o taxanos no se ha encontrado alguno que logre impactar en supervivencia global, se reportan si otros desenlaces importantes con valores similares a los reportados por el medicamento ixabepilona. El medicamento está disponible a nivel nacional y ha sido aprobado tanto por FDA, y DIGEMID para su uso en pacientes con cáncer de mama metastásico. No está aprobado por EMA. Con respecto al costo, éste podría exceder en 30 mil nuevos soles comparado al resto de alternativas disponibles en la lista PNUME. Se estima que por cada paciente se requiere aproximadamente 8 UIT. Finalmente, el panel multidisciplinario debido a la evidencia mostrada y la experiencia institucional, no tiene como justificar la continuidad de la terapia brindando opinión en contra de la cobertura del medicamento Ixabepilona. Se elevará informe y acta a Comité Farmacoterapéutico sobre los acuerdos de reunión.