Ranibizumab for the treatment of neovascular AMD

Design and development of the MacTSQ measure of satisfaction with treatment for macular conditions used within the IVAN trial

Background

The purpose of the study was to design a measure of patient satisfaction with treatment for macular disease, the MacTSQ, and to carry out psychometric evaluation of the measure. The measure was designed along the lines of the widely used Diabetes Treatment Satisfaction Questionnaire (DTSQ) and sister measures of treatment satisfaction for other conditions including diabetic retinopathy. Information was also gathered during in-depth interviews with 20 people who had experienced one of a range of treatments for macular degeneration. In a prospective study, the newly designed 16-item MacTSQ, was used in a multi-centre, randomised, double-blind clinical trial (the IVAN study) comparing two treatments for neovascular age-related macular degeneration and two treatment schedules: 1. continual monthly treatments (continuous arm), 2. initial 3 monthly treatments then monitoring and retreatment if necessary (discontinuous arm). The MacTSQ was administered after the first three treatments and at 12 and 24 months. Psychometric development was carried out using data from 137 patients. Sensitivity and validity of the MacTSQ were investigated using baseline and 12-month data.

Results

Exploratory factor analysis yielded two subscales i) convenience, information and overall satisfaction (6 Items: Cronbach’s alpha = 0.740), and ii) safety, efficacy and discomfort (6 Items: alpha = 0.776). Twelve items also loaded on to a single scale (alpha = 0.815). Three items were removed from the scale but retained in the questionnaire for separate analysis where required. Greater satisfaction was reported at time 2 (12 months) than time 1 (after 3 monthly injections) on the safety, efficacy and discomfort subscale (W = 3000.500. p = 0.024, n = 108). Participants whose vision improved reported greater satisfaction than those who had no improvement e.g. U = 1599, p = 0.033. Those in the discontinuous arm reported greater satisfaction on subscale 1 than those in the continuous arm at time one (U = 1870, p = 0.04) and time 2 (U = 1132.5, p = 0.023). This finding suggested a better experience in the discontinuous arm.

Conclusions

The MacTSQ will be valuable in investigating treatment satisfaction in clinical trials of new treatments or in a routine clinic situation and may highlight ways to improve patients’ experience of treatment.

Efficacy of intravitreal ranibizumab combined with Ahmed glaucoma valve implantation for the treatment of neovascular glaucoma

BACKGROUND

Neovascular glaucoma is a refractive glaucoma. Recently, anti-VEGF factors have been used alone or in combination for the treatment of neovascular glaucoma. However, the medium- and long-term efficacy of such drugs remains to be evaluated. This study was to determine the efficacy of intravitreal ranibizumab combined with Ahmed glaucoma valve implantation for the treatment of neovascular glaucoma.

METHODS

In this prospective non-randomized study, 43 neovascular glaucoma patients (43 eyes) were assigned to receive either 0.5 mg intravitreal ranibizumab for three to 14 days before Ahmed glaucoma valve implantation (injection group, n = 21) or Ahmed glaucoma valve implantation alone (control group, n = 22). The patients were followed up for six to 12 months. Differences in surgical success rate, intraocular pressure, best corrected visual acuity, anti-glaucoma medications and postoperative complications were compared between the two groups. Surgical success was defined as IOP > = 6 mm Hg and < = 21 mm Hg, with or without the use of anti-glaucoma medications, and without severe complications or reoperation.

RESULTS

Of the 43 patients, 40 completed the 6-month follow-up and 37 completed the 1-year follow-up. Success rate was 73.7% vs. 71.4% at six months and 72.2% vs. 68.4% at 12 months in the injection group and the control group respectively. No significant difference was noted between the two groups (six months: P = 0.87, 12 months: P = 1.00). There were no significant differences in the two groups with respect to intraocular pressure, best corrected visual acuity, anti-glaucoma medications or postoperative complications at six months or 12 months.

CONCLUSIONS

Single intravitreal ranibizumab (0.5 mg) before surgery has no significant effect on the medium- or long-term outcomes of neovascular glaucoma treated with Ahmed glaucoma valve implantation.

TRIAL REGISTRATION

Chinese Clinical Trial Registry ( ChiCTR-OOC-14005709, Trial registration date: 2014-12-01).

Influence of anti-VEGF about cardiovascular biomarkers in age related macular degeneration

Systemic VEGF inhibition disrupts endothelial homeostasis and accelerates the atherogenesis, suggesting that these events contribute to the clinical cardiovascular adverse events of VEGF-inhibiting therapies. The objective of the current study was to analyze the effect of anti-VEGF therapy on cardiovascular risk factors in patients with exudative age related macular degeneration. A total of 73 patients with exudative age related macular degeneration (without previous anti-VEGF therapy) were treated with two anti-VEGF: Ranibizumab and Pegaptanib sodium. The follow up was 6 months. The following parameters were determined before and after treatment: homocysteine, lipids (total cholesterol, triglycerides, HDL-c, LDL-c), C-Reactive Protein and fibrinogen. There were not statistically significant differences in parameters studied before and after treatment with both Pegaptanib sodium and Ranibizumab, except C-Reactive Protein. Of all patients analyzed, only 3 of them have initially C-Reactive Protein levels above normal levels and after antiangiogenic therapy, there was a significant increase in C-Reactive Protein. We have not found results in our study who to suspect that treatment with anti-VEGF in the patients with exudative age related macular degeneration increases cardiovascular risk predictors. However, after therapy was increased the CRP and fibrinogen may mean that anti-VEGF contribute an alteration of endothelial homeostasis in exudative AMD.

Almost total protection from age-related macular degeneration by haplotypes of the Regulators of Complement Activation

Age-related macular degeneration (AMD) is the leading cause of blindness in developed countries. It has been proposed that the polymorphism encoding Y402H (T1277C) in the complement factor H gene (CFH) is one of the main determinants of disease. We genotyped the polymorphism at a number of loci in the region encompassing the Regulators of Complement Activation (RCA) on chromosome 1, including T1277C SNP, in 187 patients and 146 controls. Haplotypes have been classified as protective (P) or susceptible (S) with respect to AMD. This included the identification of an S haplotype with a T at 1277. The results show that no single locus should be assumed to be directly responsible for AMD, but rather argue for the existence of RCA haplotypes, which can be assigned meaningful predictive values for AMD. We conclude that the critical sequences are within a region 450 kb centromeric to 128 kb telomeric of CFH.

Photobleaching kinetics of Verteporfin and Lemuteporfin in cells and optically trapped multilamellar vesicles using two-photon excitation

Verteporfin and Lemuteporfin are compared to examine the effect of their functional groups and therefore the localization in two-photon excitation (TPE) photodynamic therapy (PDT). We used singlet oxygen-related photobleaching of the sensitizers to assess TPE-induced singlet oxygen generation in multilamellar vesicles (MLVs) and U343 glioma cells under a variety of conditions. It was found that Lemuteporfin photobleached at a faster rate than Verteporfin in the majority of environments. Also, Verteporfin and Lemuteporfin exhibited different behaviors when in hypoxic environments relative to those in oxygenated MLVs. These differences are attributed to the sensitizer location in the membrane and their relative mobilities throughout membranes and cells.

Structural and mechanistic insight into how antibodies inhibit serine proteases

Antibodies display great versatility in protein interactions and have become important therapeutic agents for a variety of human diseases. Their ability to discriminate between highly conserved sequences could be of great use for therapeutic approaches that target proteases, for which structural features are conserved among family members. Recent crystal structures of antibody-protease complexes provide exciting insight into the variety of ways antibodies can interfere with the catalytic machinery of serine proteases. The studies revealed the molecular details of two fundamental mechanisms by which antibodies inhibit catalysis of trypsin-like serine proteases, exemplified by hepatocyte growth factor activator and MT-SP1 (matriptase). Enzyme kinetics defines both mechanisms as competitive inhibition systems, yet, on the molecular level, they involve distinct structural elements of the active-site region. In the steric hindrance mechanism, the antibody binds to protruding surface loops and inserts one or two CDR (complementarity-determining region) loops into the enzyme's substrate-binding cleft, which results in obstruction of substrate access. In the allosteric inhibition mechanism the antibody binds outside the active site at the periphery of the substrate-binding cleft and, mediated through a conformational change of a surface loop, imposes structural changes at important substrate interaction sites resulting in impaired catalysis. At the centre of this allosteric mechanism is the 99-loop, which is sandwiched between the substrate and the antibody-binding sites and serves as a mobile conduit between these sites. These findings provide comprehensive structural and functional insight into the molecular versatility of antibodies for interfering with the catalytic machinery of proteases.

Comparison of spectral-domain versus time-domain optical coherence tomography in management of age-related macular degeneration with ranibizumab

PURPOSE

To compare the ability to delineate and detect patterns of choroidal neovascularization (CNV) activity in patients with exudative age-related macular degeneration (AMD) after ranibizumab treatment between time-domain optical coherence tomography (TD-OCT) and 4 different spectral-domain optical coherence tomography (SD-OCT) devices.

DESIGN

Prospective, consecutive case series.

PARTICIPANTS

Sixty-one eyes of 58 patients with exudative AMD after ranibizumab treatment were included in this study.

METHODS

All patients were imaged with TD-OCT and at least 1 of 4 different SD-OCT devices at the same visit after ranibizumab treatment. The OCT images were analyzed in a masked fashion by 2 independent graders (KS, TY) to delineate and detect the presence of CNV activity defined as the presence of subretinal fluid, intraretinal cysts, intraretinal fluid, sub-retinal pigment epithelium (sub-RPE) fluid, or a combination thereof. The automated evaluation of retinal thickness also was analyzed between devices.

MAIN OUTCOME MEASURES

Evidence of CNV activity on linear B-scans and 3-dimensional so-called cube scans on SD-OCT and linear B-scan on TD-OCT.

RESULTS

In linear B-scan mode, all 4 SD-OCT devices were superior in their ability to delineate sub-RPE fluid compared with TD-OCT (P<0.05). Three of 4 SD-OCT devices were superior in delineating intraretinal fluid, and 2 of 4 SD-OCT devices were superior in delineating subretinal fluid and intraretinal cysts (P<0.05). In the 3-dimensional so-called cube mode, all 4 SD-OCT devices were superior in detecting subretinal fluid and 2 of 4 SD-OCT devices were superior in detecting sub-RPE and intraretinal fluid (P<0.05). There were significant correlations in center point thickness between all SD-OCT devices and TD-OCT (P<0.01), and 3 of 4 and 1 of 3 SD-OCT devices showed significant differences from TD-OCT in center point thickness (P<0.01) and center subfield thickness (P<0.001), respectively.

CONCLUSIONS

SD-OCT is superior to TD-OCT in evaluating for CNV activity in patients with wet AMD after ranibizumab injection. Retinal thickness measurements between SD-OCT and TD-OCT also were significantly different.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found after the references.

Personal costs of visual impairment by different eye diseases and severity of visual loss

OBJECTIVES

To determine the personal out-of-pocket costs of visual impairment and to examine the expenditure pattern related to eye diseases and the severity of visual impairment.

METHODS

This prospective cohort study recruited participants of any age who were able to converse in English and had presenting visual acuity (VA) of < 6/12. Participants completed cost diaries regarding their daily personal vision-related expenditure. These were grouped under four categories: 1) medicines, products and equipment, 2) health and community services, 3) informal care and support and 4) other expenses. Socio-demographic and clinical data were also collected.

RESULTS

In 2003 150 participants, aged between 10 and 93 years old, were recruited. The median and mean total costs of visual impairment was Australian Dollars (AUD)$2416 and $3376, respectively (mode = AUD$2001-3000, SD +/- AUD$3050, Range AUD$7-$18610). Adjusting for age, there was no effect for severity of visual impairment (mild, moderate or severe) or type of eye diseases on the annual total personal out-of-pocket costs of visual impairment (p > 0.05).

CONCLUSIONS

Regardless of the type of eye diseases and the severity of visual loss, visual impairment posed a significant financial burden to both the individual and society.

The MacDQoL individualized measure of the impact of macular degeneration on quality of life: reliability and responsiveness

PURPOSE

To investigate the MacDQoL test-retest reliability and sensitivity to change in vision over a period of one year in a sample of patients with age-related macular degeneration (AMD).

DESIGN

A prospective, observational study.

METHOD

Patients with AMD from an ophthalmologist's list (n = 135) completed the MacDQoL questionnaire by telephone interview and underwent a vision assessment on two occasions, one year apart.

RESULTS

Among participants whose vision was stable over one year (n = 87), MacDQoL scores at baseline and follow-up were highly correlated (r = 0.95; P < .0001). Twelve of the 22 scale items had intraclass correlations of >.80; only two were correlated <.7. There was no difference between baseline and follow-up scores (P = .85), indicating excellent test-retest reliability. Poorer quality of life (QoL) at follow-up, measured by the MacDQoL present QoL overview item, was associated with deterioration in both the better eye and binocular distance visual acuity [VA] (r = 0.29; P = .001, r = 0.21; P = .016, respectively; n = 135). There was a positive correlation between deterioration in the MacDQoL average weighted impact score and deterioration in both binocular near VA and reading speed (r = 0.20; P = .019, r = 0.18; P = .041, respectively; n = 135).

CONCLUSION

The MacDQoL has excellent test-retest reliability. Its sensitivity to change in vision status was demonstrated in correlational analyses. The measure indicates that the negative impact of AMD on QoL increases with increasing severity of visual impairment.

Vitreous levels of bevacizumab and vascular endothelial growth factor-A in patients with choroidal neovascularization

PURPOSE

To investigate the vitreous levels of bevacizumab and vascular endothelial growth factor-A (VEGF-A) after intravitreal injection of the drug in patients with choroidal neovascularization (CNV).

DESIGN

Interventional case series.

PARTICIPANTS

Eleven eyes of 11 patients with submacular hemorrhage and CNV due to age-related macular degeneration (n = 10) or angioid streaks (n = 1).

METHODS

All patients were treatment naïve except for a single dose of intravitreal injection of bevacizumab (1.25 mg/50 muL dose) and subsequent vitrectomy after various intervals (1-101 days) because of active and progressive lesion. Intravitreal free bevacizumab and VEGF-A levels were measured using enzyme-linked immunosorbent assay and microsphere-based immunoassay, respectively. Vitreous VEGF-A isoforms were analyzed by sodium dodecyl sulfate polyacrylamide gel electrophoresis and Western blotting.

MAIN OUTCOME MEASURES

Intravitreal bevacizumab and VEGF-A levels were measured and pharmacokinetic parameters were calculated.

RESULTS

Pharmacokinetics of intravitreal bevacizumab followed a 2-compartment model with initial and terminal half-lives of 0.5 and 6.7 days, respectively. Bevacizumab could be detected in all cases, ranging from 2.63 ng/ml to 165 microg/ml. The peak concentration was observed on the second day after intravitreal bevacizumab injection. Vitreous free VEGF-A levels ranged from 0.2 to 33.9 pg/ml and showed a negative correlation with the bevacizumab concentration (P<0.001; r = -0.955) and a positive correlation with time (P<0.001; r = 0.964). However, the percentage expression of VEGF-A(165) exhibited a positive correlation with the bevacizumab concentration (P = 0.032, r = 0.645) and a negative correlation with time (P = 0.007, r = -0.755). A time-dependent increase was found for the percentage expression of VEGF-A(189) (P = 0.023, r = 0.673). Neither bevacizumab- nor time-related alterations were found for VEGF-A(121).

CONCLUSIONS

Based on pharmacokinetics, the interval of 6-7 weeks would be appropriate for efficacy, although clinical trials should guide dosing recommendations. Vitreous levels of free VEGF-A showed a negative correlation with the bevacizumab concentration, which confirmed the in vivo binding affinity of bevacizumab to VEGF-A. The analysis of the VEGF-A isoforms suggests differences of interaction between bevacizumab and individual VEGF-A isoforms.