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.

A PD-L1 Aptamer Selected by Loss-Gain Cell-SELEX Conjugated with Paclitaxel for Treating Triple-Negative Breast Cancer

BACKGROUND The clinical challenges of triple-negative breast cancer (TNBC) includes the lack of targeted therapy and chemoresistance. TNBC has relatively high PD-L1 expression, and PD-L1 antibody in combination with nab-paclitaxel has been approved by FDA for TNBC treatment. Aptamers, also termed chemical antibody, are widely used in targeted drug delivery. The present study aimed to select a DNA aptamer that could specifically bind and deliver drugs to TNBC cells. MATERIAL AND METHODS An innovative loss-gain cell-SELEX strategy was used to select DNA aptamer for PD-L1 protein. Construction of PD-L1 knock-out and over-expression MDA-MB-231 cell lines were conducted through transfection and confirmed by western blot and flow cytometry. Confocal microscopy and flow cytometry were used to analyze the binding ability of aptamer with TNBC cells. The cytotoxicity of aptamer-paclitaxel complex against TNBC cells was evaluated by Cell Counting Kit-8 assay. The reactivation of the T cell function by aptamer was measured by IL-2 enzyme-linked immunosorbent assay after T cells co-cultured with tumor cells. RESULTS In this work, using an innovative loss-gain cell-SELEX strategy, we screened a PD-L1-targeting aptamer. PD-L1 aptamer selectively bound to PD-L1 over-expressed TNBC cells with a dissociation constant in the nanomolar range. PD-L1 aptamer could also inhibit PD-1/PD-L1 interaction and restore the function of T cells. Moreover, we developed a PD-L1 aptamer-paclitaxel conjugate which showed improved cellular uptake and anti-proliferation efficacy in PD-L1 over-expressed TNBC cells. CONCLUSIONS In summary, these findings suggest that the selected PD-L1 aptamer might have potential implication in immune modulation and targeted therapy against TNBC.

Cotinine-conjugated aptamer/anti-cotinine antibody complexes as a novel affinity unit for use in biological assays

Aptamers are synthetic, relatively short (e.g., 20-80 bases) RNA or ssDNA oligonucleotides that can bind targets with high affinity and specificity, similar to antibodies, because they can fold into unique, three-dimensional shapes. For use in various assays and experiments, aptamers have been conjugated with biotin or digoxigenin to form complexes with avidin or anti-digoxigenin antibodies, respectively. In this study, we developed a method to label the 5' ends of aptamers with cotinine, which allows formation of a stable complex with anti-cotinine antibodies for the purpose of providing another affinity unit for the application in biological assays using aptamers. To demonstrate the functionality of this affinity unit in biological assays, we utilized two well-known aptamers: AS1411, which binds nucleolin, and pegaptanib, which binds vascular endothelial growth factor. Cotinine-conjugated AS1411/ anti-cotinine antibody complexes were successfully applied to immunoblot, immunoprecipitation, and flow cytometric analyses, and cotinine-conjugated pegaptanib/ anti-cotinine antibody complexes were used successfully in enzyme immunoassays. Our results show that cotinine-conjugated aptamer/anti-cotinine antibody complexes are an effective alternative and complementary technique for aptamer use in multiple assays and experiments.

Anti-vascular endothelial growth factor biosimilars for neovascular age-related macular degeneration

RATIONALE

Neovascular age-related macular degeneration (AMD) is a progressive eye disease characterized by choroidal neovascularization (CNV) and is a leading cause of vision loss and disability worldwide. Although intravitreal anti-vascular endothelial growth factor (anti-VEGF) therapy is an effective treatment option that helps to prevent vision loss or to improve visual acuity in people with neovascular AMD, treatment imposes a significant financial burden on patients and healthcare systems. A biosimilar is a biological product that has been developed to be nearly identical to a previously approved biological product. The use of biosimilars may help reduce costs and so may increase patient access to effective biologic medicines with similar levels of safety to the drugs on which they are based.

OBJECTIVES

To assess the benefits and harms of anti-VEGF biosimilar agents compared with their corresponding anti-VEGF agents (i.e. the reference products) that have obtained regulatory approval for intravitreal injections in people with neovascular AMD.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, two other databases, and two trials registries together with reference checking and contact with study authors to identify studies that are included in the review. The latest search date was 2 June 2023.

ELIGIBILITY CRITERIA

We included randomized controlled trials (RCTs) that compared approved anti-VEGF biosimilars with their reference products for treating the eyes of adult participants (≥ 50 years) who had an active primary or recurrent choroidal neovascularization lesion secondary to neovascular AMD.

OUTCOMES

Our outcomes were: best-corrected visual acuity (BCVA), central subfield thickness (CST), vision-related quality of life, serious ocular and non-ocular adverse events (AE), treatment-emergent adverse events (TEAEs), anti-drug antibodies (ADAs), and serum concentrations of biosimilars and reference drugs.

RISK OF BIAS

We assessed the risk of bias (RoB) for seven outcomes reported in a summary of findings table by using the Cochrane RoB 2 tool.

SYNTHESIS METHODS

We synthesized results for each outcome using meta-analysis, where possible, by calculating risk ratios (RR) and mean differences (MD) with 95% confidence intervals (CI) for dichotomous outcomes and continuous outcomes, respectively. Where this was not possible due to the nature of the data, we summarized the results narratively. We used GRADE to assess the certainty of evidence for prespecified outcomes.

INCLUDED STUDIES

We included nine parallel-group multi-center RCTs that enrolled a total of 3814 participants (3814 participating eyes), with sample sizes that ranged from 160 to 705 participants per study. The mean age of the participants in these studies ranged from 67 to 76 years, and the proportion of women ranged from 26.5% to 58.7%. Ranibizumab (Lucentis) was the reference product in seven studies, and aflibercept (Eyelea) was the reference product in two others. All the included studies had been supported by industry. The follow-up periods ranged from 12 to 52 weeks (median 48 weeks). Five studies (56%) were conducted in multi-country settings across Europe, North America and Asia, two studies in India, and one each in Japan and the Republic of Korea. We judged all the included studies to have met high methodological standards.

SYNTHESIS OF RESULTS

With regard to efficacy, our meta-analyses demonstrated that anti-VEGF biosimilars for neovascular AMD resulted in little to no difference compared with the reference products for BCVA change at 8 to 12 weeks (MD -0.55 Early Treatment Diabetic Retinopathy Study (ETDRS) letters, 95% CI -1.17 to 0.07; 8 studies, 3603 participants; high-certainty evidence) and the proportion of participants who lost fewer than 15 letters in BCVA at 24 to 48 weeks (RR 0.99, 95% CI 0.98 to 1.01; 7 studies, 2658 participants; moderate-certainty evidence). Almost all participants (96.6% in the biosimilar group and 97.0% in the reference product group) lost fewer than 15 letters in BCVA. The evidence from two studies suggested that there was no evidence of difference between biosimilars and reference products in vision-related quality of life measured by the 25-item National Eye Institute Visual Function Questionnaire (NEI-VFQ-25) summary scores at 24 to 48 weeks (MD 0.82, 95% CI -0.70 to 2.35; 2 studies, 894 participants; moderate-certainty evidence). With regard to the safety profile, meta-analyses also revealed little to no difference between anti-VEGF biosimilars and the reference products for the proportion of participants who experienced serious ocular AEs (RR 1.24, 95% CI 0.68 to 2.26; 7 studies, 3292 participants; moderate-certainty evidence), and for TEAEs leading to investigational product discontinuation or death (RR 0.96, 95% CI 0.63 to 1.46; 8 studies, 3497 participants; moderate-certainty evidence). Overall, 1.4% of participants in the biosimilar group and 1.2% in the reference product group experienced serious ocular adverse events. The most frequently documented serious ocular AEs were retinal hemorrhage and endophthalmitis. Although the evidence is of low certainty due to imprecision, meta-analysis suggested that anti-VEGF biosimilars led to no difference compared with the reference products for cumulative incidence of ADAs (RR 0.84, 95% CI 0.58 to 1.22; 8 studies, 3066 participants; low-certainty evidence) or mean maximum serum concentrations (MD 0.42 ng/mL, 95% CI -0.22 to 1.05; subgroup of 3 studies, 100 participants; low-certainty evidence). We judged the overall risk of bias to be low for all studies.

AUTHORS' CONCLUSIONS

In our review, low to high certainty evidence suggests that there is little to no difference, to date, between the anti-VEGF biosimilars approved for treating neovascular AMD and their reference products in terms of benefits and harms. While anti-VEGF biosimilars may be a viable alternative to reference products, current evidence for their use is based on a limited number of studies - particularly for comparison with aflibercept - with sparse long-term safety data, and infrequent assessment of quality of life outcomes. Our effect estimates and conclusions may be modified once findings have been reported from studies that are currently ongoing, and studies of biosimilar agents that are currently in development.

FUNDING

Cochrane Eyes and Vision US Project is supported by grant UG1EY020522, National Eye Institute, National Institutes of Health. Takeshi Hasegawa and Hisashi Noma were supported by Grant-in-Aid for Scientific Research from the Japan Society for the Promotion of Science (Grant numbers: 22H03554, 19K03092, 24K06239).

REGISTRATION

Protocol available via doi.org/10.1002/14651858.CD015804.