With the identification of vascular endothelial growth factor (VEGF) and the confirmation of its pathophysiologic link to retinal and choroidal angiogenesis, numerous agents have been designed to ...inhibit its activity. It is noteworthy that anatomic and visual benefits have been associated with the use of anti-VEGF agents such as pegaptanib (Macugen) and to a greater extent, ranibizumab (Lucentis) and bevacizumab (Avastin), particularly in the management of neovascular age-related macular degeneration (AMD). Clinical trials and case series have confirmed the utility of these agents. However, shortcomings of the current drugs such as short half-life, intraocular dosing, limited effectiveness in some patients, and potential systemic side effects continue to drive the development of new agents. In this article, we review current anti-VEGF therapies and discuss future developments.
Age-related macular degeneration (AMD) is a leading cause of visual impairment in aging populations in industrialized countries. Here we investigated whether the genotype of vascular endothelial ...growth factor A (VEGFA) gene is associated with response to anti-VEGF therapy. 223 eyes with neovascular AMD were treated with intravitreal anti-VEGF therapy. Responders were defined as patients who had an improvement in best corrected visual acuity (BCVA) of at least 5 letters or one line on the EDTRS visual acuity chart along with resolution of intraretinal or subretinal fluid over 12 months. Patients who did not meet the definition of responders were classified as poor-responders. The vision of responders (n = 148) improved while the vision of poor-responders (n = 75) worsened (P<0.001). Responders on average had a decrease in central foveal thickness (CFT), while poor-responders had an increase in CFT (P <0.001). Compared with the responder group, the poor-responder group had a higher frequency of the risk (T) allele (Allelic P = 0.019) and TT genotype (P = 0.002 under a recessive model) for the VEGFA-rs943080 polymorphism. VEGFA expression was 1.8-fold higher in cells with the VEGFA rs943080 TT genotype than in cells with the VEGFA rs943080 CC genotype (P = 0.012). Age, gender, smoking, diabetes mellitus, and hypertension did not play a significant role in treatment response, but BMI was found to be significantly different between responders and poorresponders (P = 0.033). In conclusion, we demonstrated a potential pharmacogenetic relationship between the VEGFA gene and treatment response to anti-VEGF therapy.The studies are registered at ClinicalTrials.gov under the identifiers NCT00474695 (http://clinicaltrials. gov/ct2/show/NCT00474695) and NCT01464723 (http://clinicaltrials.gov/ct2/show/NCT01464723).
To compare the efficacy of ranibizumab 0.5-mg and 2.0-mg intravitreal injections for persistent diabetic macular edema (DME) previously treated with bevacizumab.
In all, 43 patients with residual ...center-involved DME following intravitreal bevacizumab were included in this 12-month prospective, nonrandomized, multicenter study. Enrolled patients received three monthly ranibizumab 0.5-mg injections. At month 3, patients with residual macular edema switched to three monthly injections of ranibizumab 2.0-mg. Assessments included monthly visual acuity and spectral-domain optical coherence tomography.
Mean visual acuity improved by +6.4 letters at month 3 and +8.8 letters at month 6. Mean central subfield thickness (CST) decreased by -113 μm at month 3 and -165 μm at month 6. Before enrollment, 29/43 (67.4%) patients showed <10% CST reduction following monthly bevacizumab treatment. After three monthly ranibizumab 0.5-mg injections, 22/29 (75.9%) patients showed >10% reduction in CST, whereas 6 showed <10% reduction. Of these six, three (50%) showed >10% reduction in CST after switching to three monthly ranibizumab 2.0-mg doses. No serious adverse events were observed to month 6.
Ranibizumab 0.5-mg or 2.0-mg may improve visual and anatomic outcomes in patients with DME who demonstrated minimal or no response to bevacizumab therapy. Moreover, increased dosage of ranibizumab (2.0-mg) may provide additional benefit over ranibizumab 0.5-mg in some patients. However, 2.0-mg ranibizumab is not currently commercially licensed or available.
To report the short-term safety, biologic effect, and a possible mechanism of action of intravitreal bevacizumab in patients with neovascular age-related macular degeneration (AMD).
Interventional, ...consecutive, retrospective case series.
Eighty-one eyes of 79 patients with subfoveal neovascular AMD.
Patients received intravitreal bevacizumab (1.25 mg) on a monthly basis until macular edema, subretinal fluid (SRF), and/or pigment epithelial detachment (PED) resolved. Ophthalmic evaluations included nonstandardized Snellen visual acuity (VA), complete ophthalmic examination, fluorescein angiography, and optical coherence tomography (OCT).
Assessments of safety, changes in Snellen VA, OCT retinal thickness, and angiographic lesion characteristics were performed.
No significant ocular or systemic side effects were observed. Most patients (55%) had a reduction of >10% of baseline retinal thickness at 1 week after the injection. At 4 weeks after injection, 30 of 81 eyes demonstrated complete resolution of retinal edema, SRF, and PEDs. Of the 51 eyes with 8 weeks' follow-up, 25 had complete resolution of retinal thickening, SRF, and PEDs. At 1, 4, 8,and 12 weeks, the mean retinal thickness of the central 1 mm was decreased by 61, 92, 89, and 67 mum, respectively (P<0.0001 for 1, 4, and 8 weeks and P<0.01 for 12 weeks). At 4 and 8 weeks, mean VA improved from 20/200 to 20/125 (P<0.0001). Median vision improved from 20/200 to 20/80(-) at 4 weeks and from 20/200 to 20/80 at 8 weeks.
Short-term results suggest that intravitreal bevacizumab (1.25 mg) is well tolerated and associated with improvement in VA, decreased retinal thickness by OCT, and reduction in angiographic leakage in most patients, the majority of whom had previous treatment with photodynamic therapy and/or pegaptanib. Further evaluation of intravitreal bevacizumab for the treatment of choroidal neovascularization is warranted.
To solve a statistical decision problem from a Bayesian viewpoint, the decision maker must specify a probability distribution on the parameter space, his prior distribution. In order to analyze the ...influence of this prior distribution on the solution of the problem, Bernardo (1981) proposed to compare the results with those that one would obtain by using that prior distribution which maximizes the useful experimental information, thus introducing the concept of reference decision. This definition is too involved for most of the problems usually found in practice. Here we analyze situations in which it is possible to simplify the definition of the reference decision, and we provide conditions guaranteeing the existence of such decisions.PUBLICATION ABSTRACT
Deriving Reference Decisions Rabena, M
TEST: An Official Journal of the Spanish Society of Statistics and Operations Research,
1998, Letnik:
7, Številka:
1
Journal Article
Collective metastasis is defined as the cohesive migration and metastasis of multicellular tumor cell clusters. Disrupting various cell adhesion genes markedly reduces cluster formation and ...colonization efficiency, yet the downstream signals transmitted by clustering remain largely unknown. Here, we use mouse and human breast cancer models to identify a collective signal generated by tumor cell clusters supporting metastatic colonization. We show that tumor cell clusters produce the growth factor epigen and concentrate it within nanolumina—intercellular compartments sealed by cell-cell junctions and lined with microvilli-like protrusions. Epigen knockdown profoundly reduces metastatic outgrowth and switches clusters from a proliferative to a collective migratory state. Tumor cell clusters from basal-like 2, but not mesenchymal-like, triple-negative breast cancer cell lines have increased epigen expression, sealed nanolumina, and impaired outgrowth upon nanolumenal junction disruption. We propose that nanolumenal signaling could offer a therapeutic target for aggressive metastatic breast cancers.
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•Breast tumor cell clusters contain nanolumina—sealed, intercellular cavities•Clusters produce the growth factor epigen and concentrate it in nanolumina•Epigen is regulated during metastasis, and its suppression reduces outgrowth•Basal-like 2 breast cancer clusters highly express epigen and form nanolumina
Nanolumina encased within clusters of tumor cells harbor signaling molecules that promote metastasis.
Stroke represents an attractive target for stem cell therapy. Although different types of cells have been employed in animal models, a direct comparison between cell sources has not been performed. ...The aim of our study was to assess the effect of human multipotent adult progenitor cells (hMAPCs) and human mesenchymal stem cells (hMSCs) on endogenous neurogenesis, angiogenesis and inflammation following stroke. BALB/Ca-RAG 2(-/-) γC(-/-) mice subjected to FeCl(3) thrombosis mediated stroke were intracranially injected with 2 × 10(5) hMAPCs or hMSCs 2 days after stroke and followed for up to 28 days. We could not detect long-term engraftment of either cell population. However, in comparison with PBS-treated animals, hMSC and hMAPC grafted animals demonstrated significantly decreased loss of brain tissue. This was associated with increased angiogenesis, diminished inflammation and a glial-scar inhibitory effect. Moreover, enhanced proliferation of cells in the subventricular zone (SVZ) and survival of newly generated neuroblasts was observed. Interestingly, these neuroprotective effects were more pronounced in the group of animals treated with hMAPCs in comparison with hMSCs. Our results establish cell therapy with hMAPCs and hMSCs as a promising strategy for the treatment of stroke.
Assessment of biological effect, visual acuity changes, and safety of intravitreal (IVT) ranibizumab in patients with macular edema associated with perfused central retinal vein occlusion (CRVO).
...Ongoing, prospective, open-label, single-center, uncontrolled study.
Ten adult patients with macular edema associated with perfused CRVO.
Patients were randomly assigned to receive 3 monthly IVT injections of either 0.3 or 0.5 mg ranibizumab (n = 5 at each dose). Additional injections were administered quarterly as needed over the ensuing 21 months at the physician's discretion for recurrent or persistent macular edema.
The predetermined primary endpoint was the percentage of patients gaining >or=15 letters of best-corrected Early Treatment of Diabetic Retinopathy Study visual acuity (BCVA). The secondary endpoints include the mean change in BCVA and central retinal thickness (CRT) measured by optical coherence tomography, the rate of progression to ischemic CRVO, extent of intraocular hemorrhage, retinal vein diameter, optic nerve head swelling, and the incidence and severity of ocular and nonocular adverse events.
After 3, 6, and 9 months of follow-up, 40%, 10%, and 30% of patients, respectively, gained >or=15 letters in BCVA; mean BCVA improved by 12+/-20 letters, 3+/-21 letters, and 1+/-24 letters, respectively, compared with baseline; CRT showed a mean decrease of 272+/-244 microm, 88+/-178 microm, and 119+/-153 microm, compared with baseline. No significant differences were observed between the 0.3- and 0.5-mg doses. Most patients experienced decreases in the extent of retinal hemorrhage, retinal vein diameter, and optic nerve head swelling at months 3 and 6 compared with baseline. No patients progressed to ischemic CRVO or experienced a severe adverse event that was attributed to ranibizumab.
Ranibizumab is generally well-tolerated and may improve BCVA and decrease CRT. The improvements in BCVA and CRT observed during the initial monthly injection period (0 to 3 months) were possibly lost to the recurrence of macular edema in between ranibizumab injection during the quarterly treatments (3 to 9 months). The extent of retinal hemorrhage, retinal vein diameter, and nerve swelling continued to normalize for most of the patients from baseline to 6 months. Follow-up is ongoing, and alternative dosing regimens are being evaluated.
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