Oligonucleotide aptamers against tyrosine kinase receptors: Prospect for anticancer applications.

Transmembrane receptor tyrosine kinases (RTKs) play crucial roles in cancer cell proliferation, survival, migration and differentiation. Area of intense research is searching for effective anticancer therapies targeting these receptors and, to date, several monoclonal antibodies and small-molecule tyrosine kinase inhibitors have entered the clinic. However, some of these drugs show limited efficacy and give rise to acquired resistance. Emerging highly selective compounds for anticancer therapy are oligonucleotide aptamers that interact with their targets by recognizing a specific three-dimensional structure. Because of their nucleic acid nature, the rational design of advanced strategies to manipulate aptamers for both diagnostic and therapeutic applications is greatly simplified over antibodies. In this manuscript, we will provide a comprehensive overview of oligonucleotide aptamers as next generation strategies to efficiently target RTKs in human cancers.

Olaptesed pegol (NOX-A12) with bendamustine and rituximab: a phase IIa study in patients with relapsed/refractory chronic lymphocytic leukemia.

Olaptesed pegol (NOX-A12) is a pegylated structured L-oligoribonucleotide that binds and neutralizes CXCL12, a chemokine tightly regulating the life cycle of chronic lymphocytic leukemia cells. The resulting inhibition of CXCR4 and CXCR7 signaling reduces the protective activity of the bone marrow and lymph node microenvironment. CXCL12 inhibition mobilizes chronic lymphocytic leukemia cells into the circulation and prevents their homing into the protective niches. In this phase I/II study, 28 patients with relapsed/refractory chronic lymphocytic leukemia were treated with olaptesed pegol in combination with bendamustine and rituximab. Combination treatment was preceded by single escalating pilot doses of olaptesed pegol in the first ten patients for evaluation of safety and pharmacokinetics. Peak concentrations and systemic exposure of olaptesed pegol were dose-linear; plasma elimination was monophasic with a 53.2 h half-life. A rapid increase in circulating chronic lymphocytic leukemia cells was observed already 1 h after administration of olaptesed pegol and lasted for at least 72 h. Single-agent treatment was well tolerated and no dose-limiting toxicity was observed. The combination regimen yielded an overall response rate of 86%, with 11% of patients achieving a complete response and 75% a partial response. Notably, all ten high-risk patients, including four with a 17p deletion, responded to treatment. The median progression-free survival was 15.4 (95% confidence interval: 12.2, 26.2) months while the median overall survival was not reached with >80% of patients alive after a median follow-up of 28 months. Olaptesed pegol was well tolerated and did not result in additional toxicity when combined with bendamustine and rituximab (ClinicalTrials.gov identifier: NCT01486797). Further clinical development of this novel CXCL12 inhibitor is thus warranted.

Emerging applications of aptamers for anticoagulation and hemostasis.

PURPOSE OF REVIEW: Since the selection of the first thrombin-binding aptamer in 1992, the use of nucleic acid aptamers to target specific coagulation factors has emerged as a valuable approach for generating novel anticoagulant and procoagulant therapeutics. Herein, we highlight the most recent discoveries involving application of aptamers for those purposes. RECENT FINDINGS: Learning from the successes and pitfalls of the FIXa-targeting aptamer pegnivacogin in preclinical and clinical studies, the latest efforts to develop antidote-controllable anticoagulation strategies for cardiopulmonary bypass that avoid unfractionated heparin involve potentiation of the exosite-binding factor X (FX)a aptamer 11F7t by combination with either a small molecule FXa catalytic site inhibitor or a thrombin aptamer. Recent work has also focused on identifying aptamer inhibitors of contact pathway factors such as FXIa and kallikrein, which may prove to be well tolerated and effective antithrombotic agents in certain clinical settings. Finally, new approaches to develop procoagulant aptamers to control bleeding associated with hemophilia and other coagulopathies involve targeting activated protein C and tissue plasminogen activator. SUMMARY: Overall, these recent findings exemplify the versatility of aptamers to modulate a variety of procoagulant and anticoagulant factors, along with their capacity to be used complementarily with other aptamers or drugs for wide-ranging applications.

Anti-vascular endothelial growth factor (VEGF) drugs for treatment of retinopathy of prematurity.

BACKGROUND: Vascular endothelial growth factor (VEGF) plays a key role in angiogenesis in foetal life. Researchers have recently attempted to use anti-VEGF agents for the treatment of retinopathy of prematurity (ROP), a vasoproliferative disorder. The safety and efficacy of these agents in preterm infants with ROP is currently uncertain. OBJECTIVES: To evaluate the efficacy and safety of anti-VEGF drugs when used either as monotherapy, that is without concomitant cryotherapy or laser therapy, or in combination with planned cryo/laser therapy in preterm infants with type 1 ROP (defined as zone I any stage with plus disease, zone I stage 3 with or without plus disease, or zone II stage 2 or 3 with plus disease). SEARCH METHODS: We searched the Cochrane Central Register of Controlled Trials (CENTRAL 2016, Issue 11), MEDLINE (1966 to 11 December 2016), Embase (1980 to 11 December 2016), CINAHL (1982 to 11 December 2016), and conference proceedings. SELECTION CRITERIA: Randomised or quasi-randomised controlled trials that evaluated the efficacy or safety of administration, or both, of anti-VEGF agents compared with conventional therapy in preterm infants with ROP. DATA COLLECTION AND ANALYSIS: We used standard Cochrane and Cochrane Neonatal methods for data collection and analysis. We used the GRADE approach to assess the quality of the evidence. MAIN RESULTS: Six trials involving a total of 383 infants fulfilled the inclusion criteria. Five trials compared intravitreal bevacizumab (n = 4) or ranibizumab (n = 1) with conventional laser therapy (monotherapy), while the sixth study compared intravitreal pegaptanib plus conventional laser therapy with laser/cryotherapy (combination therapy).When used as monotherapy, bevacizumab/ranibizumab did not reduce the risk of complete or partial retinal detachment (3 studies; 272 infants; risk ratio (RR) 1.04, 95% confidence interval (CI) 0.21 to 5.13; risk difference (RD) 0.00, 95% CI -0.04 to 0.04; very low-quality evidence), mortality before discharge (2 studies; 229 infants; RR 1.50, 95% CI 0.26 to 8.75), corneal opacity requiring corneal transplant (1 study; 286 eyes; RR 0.34, 95% CI 0.01 to 8.26), or lens opacity requiring cataract removal (3 studies; 544 eyes; RR 0.15, 95% CI 0.01 to 2.79). The risk of recurrence of ROP requiring retreatment also did not differ between groups (2 studies; 193 infants; RR 0.88, 95% CI 0.47 to 1.63; RD -0.02, 95% CI -0.12 to 0.07; very low-quality evidence). Subgroup analysis showed a significant reduction in the risk of recurrence in infants with zone I ROP (RR 0.15, 95% CI 0.04 to 0.62), but an increased risk of recurrence in infants with zone II ROP (RR 2.53, 95% CI 1.01 to 6.32). Pooled analysis of studies that reported eye-level outcomes also revealed significant increase in the risk of recurrence of ROP in the eyes that received bevacizumab (RR 5.36, 95% CI 1.22 to 23.50; RD 0.10, 95% CI 0.03 to 0.17). Infants who received intravitreal bevacizumab had a significantly lower risk of refractive errors (very high myopia) at 30 months of age (1 study; 211 eyes; RR 0.06, 95% CI 0.02 to 0.20; RD -0.40, 95% CI -0.50 to -0.30; low-quality evidence).When used in combination with laser therapy, intravitreal pegaptanib was found to reduce the risk of retinal detachment when compared to laser/cryotherapy alone (152 eyes; RR 0.26, 95% CI 0.12 to 0.55; RD -0.29, 95% CI -0.42 to -0.16; low-quality evidence). The incidence of recurrence of ROP by 55 weeks' postmenstrual age was also lower in the pegaptanib + laser therapy group (76 infants; RR 0.29, 95% CI 0.12 to 0.7; RD -0.35, 95% CI -0.55 to -0.16; low-quality evidence). There was no difference in the risk of perioperative retinal haemorrhages between the two groups (152 eyes; RR 0.62, 95% CI 0.24 to 1.56; RD -0.05, 95% CI -0.16 to 0.05; very low-quality evidence). However, the risk of delayed systemic adverse effects with any of the three anti-VEGF drugs is not known. AUTHORS' CONCLUSIONS: Implications for practice: Intravitreal bevacizumab/ranibizumab, when used as monotherapy, reduces the risk of refractive errors during childhood but does not reduce the risk of retinal detachment or recurrence of ROP in infants with type 1 ROP. While the intervention might reduce the risk of recurrence of ROP in infants with zone I ROP, it can potentially result in higher risk of recurrence requiring retreatment in those with zone II ROP. Intravitreal pegaptanib, when used in conjunction with laser therapy, reduces the risk of retinal detachment as well as the recurrence of ROP in infants with type 1 ROP. However, the quality of the evidence was very low to low for most outcomes due to risk of detection bias and other biases. The effects on other critical outcomes and, more importantly, the long-term systemic adverse effects of the drugs are not known. Insufficient data precludes strong conclusions favouring routine use of intravitreal anti-VEGF agents - either as monotherapy or in conjunction with laser therapy - in preterm infants with type 1 ROP. IMPLICATIONS FOR RESEARCH: Further studies are needed to evaluate the effect of anti-VEGF agents on structural and functional outcomes in childhood and delayed systemic effects including adverse neurodevelopmental outcomes.

Anti-vascular endothelial growth factor for diabetic macular oedema: a network meta-analysis.

BACKGROUND: Diabetic macular oedema (DMO) is a common complication of diabetic retinopathy. Antiangiogenic therapy with anti-vascular endothelial growth factor (anti-VEGF) can reduce oedema, improve vision and prevent further visual loss. These drugs have replaced laser photocoagulation as the standard of care for people with DMO. OBJECTIVES: The 2014 update of this review found high-quality evidence of benefit with anti-VEGF modalities, compared to laser photocoagulation, for the treatment of DMO. The objective of this updated review is to compare the effectiveness and safety of the different anti-VEGF drugs using network meta-analysis methods. SEARCH METHODS: We searched various electronic databases on 26 April 2017. SELECTION CRITERIA: We included randomised controlled trials (RCTs) that compared any anti-angiogenic drug with an anti-VEGF mechanism of action versus another anti-VEGF drug, another treatment, sham or no treatment in people with DMO. DATA COLLECTION AND ANALYSIS: We used standard Cochrane methods for pair-wise meta-analysis and we augmented this evidence using network meta-analysis methods. We focused on the relative efficacy and safety of the three most commonly used drugs as interventions of direct interest for practice: aflibercept and ranibizumab, used on-label; and off-label bevacizumab.We collected data on three efficacy outcomes (gain of 15 or more Early Treatment Diabetic Retinopathy Study (ETDRS) letters; mean change in best-corrected visual acuity (BCVA); mean change in central retinal thickness (CRT)), three safety outcomes (all severe systemic adverse events (SSAEs); all-cause death; arterial thromboembolic events) and quality of life.We used Stata 'network' meta-analysis package for all analyses. We investigated the risk of bias of mixed comparisons based on the variance contribution of each study, having assigned an overall risk of bias to each study. MAIN RESULTS: Twenty-four studies included 6007 participants with DMO and moderate vision loss, of which two studies randomised 265 eyes of 230 participants and one was a cross-over study on 56 participants (62 eyes) that was treated as a parallel-arm trial. Data were collected on drugs of direct interest from three studies on aflibercept (975 eyes), eight studies on bevacizumab (515 eyes), and 14 studies on ranibizumab (1518 eyes). As treatments of indirect interest or legacy treatment we included three studies on pegaptanib (541 eyes), five studies on ranibizumab plus prompt laser (557 eyes), one study on ranibizumab plus deferred laser (188 eyes), 13 studies on laser photocoagulation (936 eyes) and six studies on sham treatment (793 eyes).Aflibercept, bevacizumab and ranibizumab were all more effective than laser for improving vision by 3 or more lines after one year (high-certainty evidence). Approximately one in 10 people improve vision with laser, and about three in 10 people improve with anti-VEGF treatment: risk ratio (RR) versus laser 3.66 (95% confidence interval (CI) 2.79 to 4.79) for aflibercept; RR 2.47 (95% CI 1.81 to 3.37) for bevacizumab; RR 2.76 (95% CI 2.12 to 3.59) for ranibizumab. On average there was no change in visual acuity (VA) with laser after one year, compared with a gain of 1 or 2 lines with anti-VEGF treatment: laser versus aflibercept mean difference (MD) -0.20 (95% CI -0.22 to -0.17) logMAR; versus bevacizumab MD -0.12 (95% CI -0.15 to -0.09) logMAR; versus ranibizumab MD -0.12 (95% CI -0.14 to -0.10) logMAR. The certainty of the evidence was high for the comparison of aflibercept and ranibizumab with laser and moderate for bevacizumab comparison with laser due to inconsistency between the indirect and direct evidence.People receiving ranibizumab were less likely to gain 3 or more lines of VA at one year compared with aflibercept: RR 0.75 (95% CI 0.60 to 0.94), moderate-certainty evidence. For every 1000 people treated with aflibercept, 92 fewer would gain 3 or more lines of VA at one year if treated with ranibizumab (22 to 148 fewer). On average people receiving ranibizumab had worse VA at one year (MD 0.08 logMAR units, 95% CI 0.05 to 0.11), moderate-certainty evidence; and higher CRT (MD 39 µm, 95% CI 2 µm to 76 µm; low-certainty evidence). Ranibizumab and bevacizumab were comparable with respect to aflibercept and did not differ in terms of VA: RR of gain of 3 or more lines of VA at one year 1.11 (95% CI 0.87 to 1.43), moderate-certainty evidence, and difference in change in VA was 0.00 (95% CI -0.02 to 0.03) logMAR, moderate-certainty evidence. CRT reduction favoured ranibizumab by -29 µm (95% CI -58 µm to -1 µm, low-certainty evidence). There was no evidence of overall statistical inconsistency in our analyses.The previous version of this review found moderate-certainty evidence of good safety of antiangiogenic drugs versus control. This update used data at the longest available follow-up (one or two years) and found that aflibercept, ranibizumab and bevacizumab do not differ regarding systemic serious adverse events (SSAEs) (moderate- or high-certainty evidence). However, risk of bias was variable, loop inconsistency could be found and estimates were not precise enough on relative safety regarding less frequent events such as arterial thromboembolic events or death (low- or very low-certainty evidence).Two-year data were available and reported in only four RCTs in this review. Most industry-sponsored studies were open-label after one year. One large publicly-funded study compared the three drugs at two years and found no difference. AUTHORS' CONCLUSIONS: Anti-VEGF drugs are effective at improving vision in people with DMO with three to four in every 10 people likely to experience an improvement of 3 or more lines VA at one year. Aflibercept may confer some advantage over ranibizumab and bevacizumab in people with DMO at one year in visual and anatomic terms but it is unclear whether this applies to the long-term. There is a need for more evidence on the long-term (greater than two years) comparative effects of these anti-VEGF agents. Evidence from RCTs may not apply to real-world practice, where people in need of antiangiogenic treatment are often under-treated and under-monitored.We found no signals of differences in overall safety between the three antiangiogenic drugs that are currently available to treat DMO, but our estimates are imprecise for cardiovascular events and death.

Novel Drugs Implicated in Pigmented Purpuric Dermatoses.

We describe two cases of cutaneous eruptions of pigmented purpuric dermatoses (PPDs) arising after exposure to medications not previously reported in the literature as causing these reactions. Specifically, two women had biopsy-proven PPDs, one after exposure to an over-the-counter iodine supplement marketed as an extract from "Norwegian kelp," and the other after intraocular injections of pegaptanib, a vascular endothelial growth factor inhibitor. The eruption occurred shortly after beginning the medication and resolved upon discontinuation. This highlights the importance of considering over-the-counter and intraocular medications when assessing cutaneous eruptions that may be medication related, such as PPDs.

Anti-vascular endothelial growth factor for diabetic macular oedema: a network meta-analysis.

BACKGROUND: Diabetic macular oedema (DMO) is a common complication of diabetic retinopathy. Antiangiogenic therapy with anti-vascular endothelial growth factor (anti-VEGF) modalities can reduce oedema and thereby improve vision and prevent further visual loss. These drugs have replaced laser photocoagulation as the standard of care for people with DMO. OBJECTIVES: The 2014 update of this review found high-quality evidence of benefit with antiangiogenic therapy with anti-VEGF modalities, compared to laser photocoagulation, for the treatment of DMO.The objective of this updated review is to compare the effectiveness and safety of the different anti-VEGF drugs in preserving and improving vision and quality of life using network meta-analysis methods. SEARCH METHODS: We searched various electronic databases on 26 April 2017. SELECTION CRITERIA: We included randomised controlled trials (RCTs) that compared any anti-angiogenic drug with an anti-VEGF mechanism of action versus another anti-VEGF drug, another treatment, sham or no treatment in people with DMO. DATA COLLECTION AND ANALYSIS: We used standard Cochrane methods for pair-wise meta-analysis and we augmented this evidence using network meta-analysis methods. We focused on the relative efficacy and safety of the three most commonly used drugs as interventions of direct interest for practice: aflibercept and ranibizumab, used on-label; and off-label bevacizumab.We collected data on three efficacy outcomes (gain of 15 or more Early Treatment Diabetic Retinopathy Study (ETDRS) letters; mean change in best-corrected visual acuity (BCVA); mean change in central retinal thickness (CRT)), three safety outcomes (all severe systemic adverse events (SSAEs); all-cause death; arterial thromboembolic events) and quality of life.We used Stata 'network' meta-analysis package for all analyses. We investigated the risk of bias of mixed comparisons based on the variance contribution of each study, having assigned an overall risk of bias to each study. MAIN RESULTS: Twenty-four studies included 6007 participants with DMO and moderate vision loss, of which two studies randomised 265 eyes of 230 participants and one was a cross-over study on 56 participants (62 eyes) that was treated as a parallel-arm trial. Data were collected on drugs of direct interest from three studies on aflibercept (975 eyes), eight studies on bevacizumab (515 eyes), and 14 studies on ranibizumab (1518 eyes). As treatments of indirect interest or legacy treatment we included three studies on pegaptanib (541 eyes), five studies on ranibizumab plus prompt laser (557 eyes), one study on ranibizumab plus deferred laser (188 eyes), 13 studies on laser photocoagulation (936 eyes) and six studies on sham treatment (793 eyes).Aflibercept, bevacizumab and ranibizumab were all more effective than laser for improving vision by 3 or more lines after one year (high-certainty evidence). Approximately one in 10 people improve vision with laser, and about three in 10 people improve with anti-VEGF treatment: risk ratio (RR) versus laser 3.66 (95% confidence interval (CI) 2.79 to 4.79) for aflibercept; RR 2.47 (95% CI 1.81 to 3.37) for bevacizumab; RR 2.76 (95% CI 2.12 to 3.59) for ranibizumab. On average there was no change in visual acuity (VA) with laser after one year, compared with a gain of 1 or 2 lines with anti-VEGF treatment: laser versus aflibercept mean difference (MD) -0.20 (95% CI -0.22 to -0.17) logMAR; versus bevacizumab MD -0.12 (95% CI -0.15 to -0.09) logMAR; versus ranibizumab MD -0.12 (95% CI -0.14 to -0.10) logMAR. The certainty of the evidence was high for the comparison of aflibercept and ranibizumab with laser and moderate for bevacizumab comparison with laser due to inconsistency between the indirect and direct evidence.People receiving ranibizumab were less likely to gain 3 or more lines of VA at one year compared with aflibercept: RR 0.75 (95% CI 0.60 to 0.94), moderate-certainty evidence. For every 1000 people treated with aflibercept, 92 fewer would gain 3 or more lines of VA at one year if treated with ranibizumab (22 to 148 fewer). On average people receiving ranibizumab had worse VA at one year (MD 0.08 logMAR units, 95% CI 0.05 to 0.11), moderate-certainty evidence; and higher CRT (MD 39 µm, 95% CI 2 µm to 76 µm; low-certainty evidence). Ranibizumab and bevacizumab were comparable with respect to aflibercept and did not differ in terms of VA: RR of gain of 3 or more lines of VA at one year 1.11 (95% CI 0.87 to 1.43), moderate-certainty evidence, and difference in change in VA was 0.00 (95% CI -0.02 to 0.03) logMAR, moderate-certainty evidence. CRT reduction favoured ranibizumab by -29 µm (95% CI -58 µm to -1 µm, low-certainty evidence). There was no evidence of overall statistical inconsistency in our analyses.The previous version of this review found moderate-certainty evidence of good safety of antiangiogenic drugs versus control. This update used data at the longest available follow-up (one or two years) and found that aflibercept, ranibizumab and bevacizumab do not differ regarding systemic serious adverse events (SSAEs) (moderate- or high-certainty evidence). However, risk of bias was variable, loop inconsistency could be found and estimates were not precise enough on relative safety regarding less frequent events such as arterial thromboembolic events or death (low- or very low-certainty evidence).Two-year data were available and reported in only four RCTs in this review. Most industry-sponsored studies were open-label after one year. One large publicly-funded study compared the three drugs at two years and found no difference. AUTHORS' CONCLUSIONS: Anti-VEGF drugs are effective at improving vision in people with DMO with three to four in every 10 people likely to experience an improvement of 3 or more lines VA at one year. There is moderate-certainty evidence that aflibercept confers some advantage over ranibizumab and bevacizumab in people with DMO at one year in visual and anatomic terms. Relative effects among anti-VEGF drugs at two years are less well known, since most studies were short term. Evidence from RCTs may not apply to real-world practice, where people in need of antiangiogenic treatment are often under-treated and under-monitored.We found no signals of differences in overall safety between the three antiangiogenic drugs that are currently available to treat DMO, but our estimates are imprecise for cardiovascular events and death.

Therapies for macular edema associated with central retinal vein occlusion: a report by the American Academy of Ophthalmology.

PURPOSE: To review the available evidence regarding the safety and efficacy of therapies for the treatment of macular edema (ME) associated with central retinal vein occlusion (CRVO). METHODS: A literature search of the PubMed database was last conducted in March 2014 with no date restrictions but limited to articles published in English. A literature search of the Cochrane Library was also conducted in March 2014 with no date restrictions and without a language limitation. The combined searches yielded 108 citations, of which 20 were deemed clinically relevant for the Ophthalmic Technology Assessment Committee Retina/Vitreous panel to review in full text. Three additional studies were also identified for panel review. The level of evidence of these selected studies was reviewed by the panel methodologist. RESULTS: There were 7 citations representing 4 clinical trials that provided level I evidence supporting the use of anti-vascular endothelial growth factor (VEGF) pharmacotherapies for ME associated with CRVO, including intravitreal ranibizumab (2), aflibercept (3), and bevacizumab (2). There were 3 citations representing 2 studies with level I evidence for intravitreal corticosteroid injection with dexamethasone intravitreal implant (2 citations) or triamcinolone (1 citation), although cataract and glaucoma were observed in these studies. Level I evidence is available on the limited benefit of macular grid-pattern laser photocoagulation (1 citation). Eight other citations reviewed were rated as level II, and 4 citations were rated as level III. Long-term efficacy results (≥2 years of follow-up) are limited to intravitreal ranibizumab at this time, and few studies have evaluated combination therapy with anti-VEGF and corticosteroid versus monotherapy of either class of drug. CONCLUSIONS: Level I evidence indicates that intravitreal anti-VEGF pharmacotherapy is safe and effective over 2 years for ME associated with CRVO and that delay in treatment is associated with worse visual outcomes. In addition, level I evidence demonstrates short-term efficacy of intravitreal corticosteroid but also an association with a higher frequency of adverse events.

Intravitreal inhibition of complement C5a reduces choroidal neovascularization in mice.

PURPOSE: To investigate the influence of complement component C5a inhibition on laser-induced choroidal neovascularization (CNV) in mice using a C5a specific L-aptamer. METHODS: In C57BL/6 J mice CNV was induced by argon-laser, C5a-inhibitor (NOX-D20) was intravitreally injected in three concentrations: 0.3, 3.0, and 30 mg/ml. The unPEGylated derivate (NOX-D20001) was applied at 3.0 mg/ml; the vehicle (5 % glucose) was injected in controls. Vascular leakage was evaluated using fluorescence angiography, CNV area was examined immunohistochemically. Activated immune cells surrounding the CNV lesion and potential cytotoxicity were analyzed. RESULTS: Compared to controls, CNV areas were significantly reduced after NOX-D20 injection at a concentration of 0.3 and 3.0 mg/ml (p = 0.042; p = 0.016). NOX-D20001 significantly decreased CNV leakage but not the area (p = 0.007; p = 0.276). At a concentration of 30 mg/ml, NOX-D20 did not reveal significant effects on vascular leakage or CNV area (p = 0.624; p = 0.121). The amount of CD11b positive cells was significantly reduced after treatment with 0.3 and 3.0 mg/ml NOX-D20 (p = 0.027; p = 0.002). No adverse glial cell proliferation or increased apoptosis were observed at effective dosages. CONCLUSIONS: Our findings demonstrate that the targeted inhibition of complement component C5a reduces vascular leakage and neovascular area in laser-induced CNV in mice. NOX-D20 was proven to be an effective and safe agent that might be considered as a therapeutic candidate for CNV treatment. The deficiency of activated immune cells highlights promising new aspects in the pathology of choroidal neovascularization, and warrants further investigations.

Biodistribution and in vivo toxicity of aptamer-loaded gold nanostars.

This paper reports an in vivo evaluation of toxicology and biodistribution of a highly anisotropic Au nanoconstruct composed of a gold nanostar (AuNS) core and a ligand shell of a G-quadruplex DNA aptamer AS1411 (Apt) supporting both targeting and therapy capabilities. We examined the toxicity of the nanoconstructs (Apt-AuNS) at four different injected concentrations. At the highest dose tested (48 mg/kg), maximal tolerated dose was not reached. Clinical pathology showed no apparent signs of acute toxicity. Interestingly, the nanoconstructs circulated longer in female rats compared to male rats. In two different tumor models, the biodistribution of Apt-AuNS, especially tumor accumulation, was different. Accumulation of Apt-AuNS was 5 times higher in invasive breast cancer tumors compared to fibrosarcoma tumors. These results provide insight on identifying a tumor model and nanoconstruct for in vivo studies, especially when an in vitro therapeutic response is observed in multiple cancer cell lines. From the clinical editor: This study investigated the toxicity and distribution of aptamer loaded gold nanostars in a rodent model of invasive breast cancer and fibrosarcoma. Acute toxicity was not identified even in the highest studied doses. Fivefold accumulation was demonstrated in the breast cancer model compared to the fibrosarcoma model. Studies like this are critically important in further clarifying the potential therapeutic use of these nanoconstructs, especially when ex vivo effects are clearly demonstrated.

Comparative safety profiles of intravitreal bevacizumab, ranibizumab and pegaptanib: the analysis of the WHO database of adverse drug reactions.

PURPOSE: The purpose of this study is to conduct a comparative analysis of the suspected adverse drug reactions (ADRs) associated with intravitreal bevacizumab, ranibizumab and pegaptanib in the WHO database in order to have a real-life information on these drugs, which now is only based on data coming from clinical trials. METHODS: ADR reports for intravitreal use of bevacizumab, ranibizumab and pegaptanib from January 2002 to December 2012 were selected from the WHO-VigiBase. Reporting odds ratio (ROR) with confidence interval of 95 % and p value was calculated. The analysis was performed for drug-reaction pairs. The Medical Dictionary for Regulatory Activities (MedDRA) terminology for ADRs was used. RESULTS: The analysis was performed on 3180 reports corresponding to 7753 drug-reaction pairs. Significant RORs for endophthalmitis and uveitis (1.90, 95 % confidence interval (CI) 1.48-2.43, and 10.62, 6.62-17.05, respectively) were retrieved for bevacizumab, and cerebrovascular accident and myocardial infarction produced significant ROR (1.54, 1.14-2.10 and 1.73, 1.18-2.53, respectively) for ranibizumab. Pegaptanib was significantly associated with visual impairment (1.98, 1.12-3.5, p = 0.02), nausea (3.29, 1.57-6.86, p < 0.001), vomiting (2.91, 1.2-7.07, p = 0.01) and drug hypersensitivity (8.75, 3.1-24.66, p < 0.001). CONCLUSIONS: Our data showed an elevated disproportionality for cardiovascular ADRs in patients treated with ranibizumab and for infective ocular reactions in those treated with bevacizumab. No relevant safety issues were identified for pegaptanib. These findings suggest bevacizumab as a suitable choice for AMD therapy due to its effectiveness similar to that of ranibizumab, its favourable safety profile and for its lower cost.

Integrating disease progression models, non-clinical pharmacokinetic data and treatment response endpoints to optimize intravitreal dosing regimens.

OBJECTIVE: To rapidly identify patients who will ultimately respond to 1 year of therapy, and optimize their inter dose interval. MATERIALS AND METHODS: An intravitreal (IVT) ophthalmic dosing paradigm was designed based on clinical efficacy, nonclinical pharmacokinetics (PK), and disease progression modeling. Relevant non-clinical PK models were used to extrapolate IVT drug concentrations to patients. RESULTS: Modeling predicted that > 80% of patients who would respond to 1 year of IVT treatment with an improvement in best-corrected visual acuity (BCVA) could be identified after the first 2 doses of treatment. These 2 initial doses produced ~ 75% of the maximum improvement in BCVA attainable. Moreover, the models also predicted those patients who responded after 1 year of treatment may tolerate an extension of the inter dose interval to 12 weeks without significant deterioration of BCVA. In contrast, > 70% of responsive patients who did not respond to 1 year of treatment showed inadequate responses after 2 doses. CONCLUSIONS: These models use data from 2 doses to identify those patients likely to benefit after 1 year of treatment, and thereafter can lengthen their inter dose interval without deleterious effects. This method identifies potential treatment responders early, and lengthens the inter dose interval during long-term administration while allowing non-responders to pursue alternative therapies earlier, thereby minimizing risk to the patient.

Incidence of presumed endophthalmitis after intravitreal injection performed in the operating room: a retrospective multicenter study.

PURPOSE: To evaluate the incidence of presumed endophthalmitis (EO) after intravitreal injection (IVI) of anti-vascular endothelial growth factor agents performed in the operating room. METHODS: Retrospective study at 2 Swiss eye hospitals between 2004 and 2012. Hospital records were used to identify patients treated with an IVI of an anti-vascular endothelial growth factor agent between 2004 and 2012 and those treated for EO, defined as any intraocular inflammation treated with intravitreal antibiotics. All IVIs were performed using standard sterile technique in a Swiss Class 1 operating room. No patient received preinjection topical antibiotics. Postinjection topical antibiotics were used only in one hospital. RESULTS: A total of 40,011 IVIs were performed at the 2 centers during the study period. Of the IVIs, ranibizumab was injected in 36,398 (91%), bevacizumab in 3,518 (9%), aflibercept in 89 (0.2%), and pegaptanib in 6 (<0.1%). Three cases of post-IVI presumed EO occurred, yielding a combined incidence of 0.0075% per injection (95% confidence interval: 0.0026-0.0220%) or 1 case per 13,337 IVIs. Two of the three cases of EO occurred in patients using post-IVI antibiotics. All three cases followed ranibizumab injection and were culture negative by anterior chamber tap or vitreous biopsy. CONCLUSION: The risk of EO after IVI performed under the sterile conditions of the operating room was very low.

[Japan phase 3 study of pegaptanib sodium in patients with diabetic macular edema].

PURPOSE: To evaluate the efficacy and safety of intravitreal injections of pegaptanib sodium in subjects with diabetic macular edema (DME). METHODS: There were 243 subjects with DME who were randomized to receive, every 6 weeks, either an intravitreal injection of pegaptanib sodium or a sham injection. The study was double-masked for the first 24 weeks, and then an open label phase continued to week 54. The primary efficacy endpoint was evaluated at week 24, and safety was assessed throughout the 54 weeks. RESULTS AND CONCLUSION: The proportion of subjects who experienced more than 10 letters improvement of visual acuity in ETDRS chart from baseline to week 24 was statistically significantly greater (p-value = 0.0003) in the pegaptanib sodium group, 20.3%, than in the sham group, 5.0%. The incidence of treatment-related adverse events was similar between the treatment groups (pegaptanib sodium group: 10.6%, sham group: 10.0%). The reported adverse events were mainly mild or moderate ophthalmic events and related to the injection procedure. During open-label phase up to 54 weeks, no new safety concerns were identified compared with the double-masked phase. However, in light of the issue concerning proper maintenance of masking of the study treatments, the study was not considered as a well-controlled, double-masked study.

Discovery and development of therapeutic aptamers.

Therapeutic aptamers are single-stranded structured oligonucleotides that bind to protein targets with high affinity and specificity and modulate protein function. Aptamers are discovered by iterative rounds of selection for binding to the target protein, partitioning, and amplification of binding clones from a diverse starting library (SELEX). Postselection optimization of clones using chemical modification is directed at improving affinity, potency, and metabolic stability. A key attribute of therapeutic aptamers is the ability to tailor the pharmacokinetic profile by modulating the degree of metabolic stability and modulating renal clearance and rate of distribution by conjugation to various sizes of polyethylene glycol (PEG). In toxicology studies, therapeutic aptamers have been largely devoid of the previously reported oligonucleotide class effects of immune stimulation, complement activation, and anticoagulation; and the principal finding is the histologically visible accumulation of drug-related material in mononuclear phagocytes, a finding generally not considered an adverse effect. Good safety margins between the pharmacologically effective dose and toxicologically established no-adverse-effect levels have been observed consistently. There are presently seven aptamers either on the market or in clinical trials, but there is still much to be demonstrated in terms of chronic systemic use to fully realize the potential of this promising new class of drugs.

Intravitreal pegaptanib sodium (Macugen) for treatment of myopic choroidal neovascularization: a morphologic and functional study.

BACKGROUND: To report the morphologic and functional outcomes resulting from the use of intravitreal pegaptanib (IVP) sodium (Macugen) in patients with myopic choroidal neovascularization. METHODS: An open-label, nonrandomized, prospective clinical trial was performed. Morphologic outcome, such as foveal thickness, was assessed by optical coherence tomography, whereas functional outcomes were assessed by best-corrected visual acuity and microperimetry. Treatment protocol consisted of 3 consecutive IVP (0.3 mg/0.05 mL; baseline, 6th week, and 12th week). Follow-up checks were scheduled at the following intervals: baseline, 18, 24, 36, and 48 weeks. RESULTS: Twenty eyes from 20 patients were studied. All patients completed follow-up at 48 weeks. After IVP, a significant decrease in foveal thickness occurred (-20%), and at the end of follow-up, choroidal neovascularization closure was obtained in all eyes. An improvement of functional parameters was recorded in all patients (best-corrected visual acuity from 25.5 ± 8.09 letters to 45.5 ± 8.16 letters, P < 0.0001; microperimetry from 8.40 ± 2.14 dB to 10.8 ± 2.05 dB, P < 0.01). The mean number of IVP was 3, and none of patients met the re-treatment criterion during the entire follow-up period. Neither ocular nor systemic side effects were observed. CONCLUSION: The findings demonstrate that the selective inhibition of VEGF-165 isoform by IVP is an effective treatment for myopic choroidal neovascularization.

Vitreous inflammation associated with intravitreal anti-VEGF pharmacotherapy.

Vascular endothelial growth factor (VEGF) is a potent promoter of angiogenesis involved in a wide variety of physiologic processes. Intravitreal injections targeting VEGF have transformed the treatment of neovascular retinal diseases. Currently, there are four anti-VEGF agents in use: bevacizumab, ranibizumab, pegaptanib, and aflibercept. The success and frequency of anti-VEGF therapy have made the ocular safety profile of these agents of vital importance. This paper focuses on sterile endophthalmitis. In this paper, we compare the incidences of posttreatment sterile endophthalmitis among the four agents, review the mechanism of actions, and discuss the most prevalent hypotheses leading to sterile endophthalmitis.

NXP081, DNA Aptamer-Vitamin C Complex Ameliorates DNFB-Induced Atopic Dermatitis in Balb/c Mice.

Atopic dermatitis (AD) is a chronic inflammatory disease characterized by dry and itchy skin. Recently, it has been reported that oxidative stress is involved in skin diseases, possibly including AD. Vitamin C, also referred to as ascorbic acid, is a vital water-soluble compound that functions as an essential nutrient. It plays a significant role as both an antioxidant and an additive in various pharmaceutical and food products. Despite the fact that vitamin C is easily oxidized, we have developed NXP081, a single-stranded DNA aptamer that selectively binds to vitamin C, thereby inhibiting its oxidation. The objective of the current research was to examine the impact of NXP081, an animal model of AD induced by 2,4-dinitrofluorobenzene (DNFB). The experimental drug NXP081, when taken orally, showed promising results in reducing inflammation and improving the skin conditions caused by DNFB. The administration of NXP081 resulted in a significant reduction in ear swelling and a noticeable improvement in the appearance of skin lesions. In addition, the administration of NXP081 resulted in a significant decrease in the migration of mast cells in the skin lesions induced by DNFB. Moreover, NXP081 inhibited the production of interferon-gamma (IFN-γ) in CD4+ T cells that were activated and derived from the lymph nodes. Our findings provide useful information about the anti-inflammatory effect of NXP081 on AD.

Anti-vascular endothelial growth factor pharmacotherapy for diabetic macular edema: a report by the American Academy of Ophthalmology.

OBJECTIVE: To review the evidence regarding the safety and efficacy of current anti-vascular endothelial growth factor (VEGF) pharmacotherapies for the treatment of diabetic macular edema (DME). METHODS: Literature searches last were conducted in September 2011, in PubMed with no date restrictions, limited to articles published in English, and in the Cochrane Library without a language limitation. The combined searches yielded 532 citations, of which 45 were deemed clinically relevant for the authors to review in full text and to assign ratings of level of evidence to each of the selected studies with the guidance of the panel methodologists. RESULTS: At this time, there are 5 studies that provide level I evidence for intravitreal ranibizumab, alone or in combination with other treatments for DME. There is also 1 study that provides level I evidence for intravitreal pegaptanib sodium for DME. Nine studies reviewed were rated as level II, and 2 additional studies reviewed were graded as level III. Most studies do not provide information about long-term results (i.e., more than 2 years of follow-up) or the comparative efficacy of anti-VEGF pharmacotherapies. CONCLUSIONS: Review of the available literature indicates that anti-VEGF pharmacotherapy, delivered by intravitreal injection, is a safe and effective treatment over 2 years for DME. Further evidence is required to support the long-term safety of these pharmacotherapies and their comparative efficacy.

Balancing risk in ophthalmic prescribing: assessing the safety of anti-VEGF therapies and the risks associated with unlicensed medicines.

Vascular endothelial growth factor (VEGF) inhibitor medications such as ranibizumab, pegaptanib and bevacizumab are in use for the treatment of neovascular age-related macular degeneration (AMD) and other retinal conditions, although only ranibizumab and pegaptanib are approved for these conditions. In contrast, bevacizumab was developed for the intravenous systemic treatment of colorectal cancer and is not formulated for intravitreal use, but is commonly used off-label in ophthalmology. European Union legislation permits the use of drugs outside the terms of their licence ('off-label') only under certain circumstances, such as during clinical trials, compassionate/named patient use in the absence of a licensed alternative, emergency scenarios (e.g., pandemics) or at the discretion of a treating physician. In such cases, patients should be fully informed regarding their treatment and any potential risks involved. Off-label drug use can be an important tool to provide patients with treatment in cases of unmet medical need. However, the use of an unlicensed medicinal product, when a suitable licensed alternative is available, puts prescribing physicians at risk of liability if safety issues arise. Emerging clinical evidence suggests safety differences exist between ranibizumab and bevacizumab.