The use of comparative effectiveness research to inform policy decisions on the inclusion of bevacizumab for the treatment of macular diseases in Thailand's pharmaceutical benefit package

Five-year outcomes after intravitreal bevacizumab of treatment-naive eyes with macular edema secondary to CRVO in routine clinical practice: Results of the Pan-American Collaborative Retina Study (PACORES) group

PURPOSE

The purpose of this study was to report the 5-year outcomes of treatment-naive eyes with cystoid macular edema secondary to central retinal vein occlusion treated with intravitreal bevacizumab in routine clinical practice.

METHODS

We conducted multicenter retrospective non-comparative case series of 102 eyes. The main outcome measured was the change in best-corrected visual acuity (BCVA) at 5 years. Secondary outcomes included the number of injections and the change in CMT at 5 years.

RESULTS

At 5 years, the mean BCVA improved from 1.22 ± 0.58 (Snellen 20/428) at baseline to 1.00 ± 0.68 logMAR (Snellen 20/200; p < 0.0001). At 5 years, 48 (47%) eyes had a gain of ≥ 3 lines, 41 (40.2%) eyes remained within 3 lines and 13 (12.7%) eyes had a loss of ≥ 3 lines of BCVA. The CMT improved from 740 ± 243 to 322 ± 179 µm (p < 0.0001). At 5 years, 59 (57.8%) eyes had a completely dry SD-OCT. Patients received a total of 10.6 ± 6.1 (range 6-27) injections. Baseline BCVA (p < 0.0001) and the duration of symptoms prior to initial anti-VEGF injection (p = 0.0274) were the only predictive factors for BCVA at 5 years.

CONCLUSIONS

After 5 years with an average of 10.6 injections, there was a mean gain of 0.22 logMAR. In addition, more eyes achieved a BCVA of ≥ 20/40, gained ≥ 3 lines and less patients had a BCVA ≤ 20/200. Eyes with a better baseline BCVA and a shorter duration of symptoms were more likely to achieve better BCVA at 5 years.

Increased serum concentration of netrin-1 after intravitreal bevacizumab injection: is it a compensatory mechanism to counteract drug side effects?

BACKGROUND

To evaluate alterations in the serum concentrations of vascular endothelial growth factor (VEGF) and netrin-1 after intravitreal bevacizumab (BCZ) injection for the treatment of diabetic macular edema (DME).

METHODS

This prospective case-control study included a total of 50 participants assigned to one of three groups, including 10 individuals with DME and non-proliferative diabetic retinopathy (NPDR), 13 with DME, and proliferative diabetic retinopathy (PDR), and 27 healthy individuals as a control group. Serum VEGF and netrin-1 concentrations were measured by enzyme-linked immunosorbent assays (ELISAs) immediately before, as well as 1 week and 1 month after, intravitreal BCZ injection.

RESULTS

The mean VEGF serum concentrations in the PDR and NPDR groups were 388.4 and 196.9 pg/mL at baseline, respectively. After 1 week, these concentrations changed to 193.41 and 150.23 pg/mL, respectively (P = 0.001 and P = 0.005, respectively); after 1 month, the concentrations were 97.89 and 76.46 pg/mL, respectively (P = 0.001 and P = 0.009, respectively). The mean netrin-1 serum concentrations in the PDR patients and NPDR groups were 318.2 and 252.7 pg/mL at baseline, respectively. After 1 week, these concentrations increased to 476.6 and 416.3 pg/mL, respectively (P = 0.033 and P = 0.005, respectively), and after 1 month, they were 676.6 and 747.5 pg/mL, respectively (P = 0.001 and P = 0.005, respectively). The correlation analysis revealed a significant inverse relationship between changes in serum VEGF and netrin-1 concentrations in both the PDR and NPDR groups (r = - 0.685, P = 0.029).

CONCLUSIONS

Intravitreal BCZ injections work systemically to significantly decrease serum VEGF levels, leading to a significant upregulation in the concentration of another angiogenic mediator, netrin-1.

From the Hypotheses to Clinical Evidence in Retinal Therapy

The off-label, therapeutic use of intravitreal bevacizumab (IVB) in vascular retinal diseases such as diabetic macular edema and proliferative diabetic retinopathy (PDR) has increased significantly due to its ability to reduce retinal neovascularization and slow progression of disease. Here, we will review the literature and investigative developments on the use of IVB as a preoperative adjuvant to vitrectomy in severe PDR, specifically focusing on its ability to reduce intra- and postoperative complications and its risk for progression or development of traction retinal detachment. In particular, this review will highlight the natural progression of evidence from case series and observations to prospective, randomized clinical trials.

Bevacizumab for eye diseases - Legal, regulatory, and ethical overview

Vascular endothelial growth factor (VEGF) inhibitors, ranibizumab, aflibercept, and pegaptanib are approved treatments for certain eye diseases that occurs especially in the elderly. These drugs are mostly inaccessible due to their high cost. Bevacizumab is a VEGF inhibitor, approved for cancer treatment. Being a cheaper alternative, it is extensively used off-label as an intravitreal injection for the treatment of eye diseases. In this article, we have analyzed similarities and differences between bevacizumab and ranibizumab, and potential long-term safety concerns with off-label use of bevacizumab. We also analyzed legal, regulatory, and ethical background of off-label use and provided recommendations to resolve this issue. Based on the extensive clinical data, actions taken, and recommendations provided by agencies such as the National Institute for Health and Care Excellence, International Council of Ophthalmology, United Kingdom and Thailand regulatory agency, intravitreal bevacizumab has adequate evidence for controlled licensing. Claiming better safety for ranibizumab at the expense of nonaffordability cannot be considered a positive risk-benefit scenario. Intravitreal bevacizumab is being used and will continue to be used off-label, if not regulatory controlled. Licensing will ensure the availability of intravitreal bevacizumab to the patients with eye diseases, without any legal or ethical concerns for the clinicians, and will also assist in generating long-term safety data. Safest delivery formulation and dosage form should be considered for approval. Both the regulatory agency and technical experts should join and take critical decision, which will be a big step forward to making a cost-effective drug available to the public.

A real-world study of effectiveness of intravitreal bevacizumab and ranibizumab injection for treating retinal diseases in Thailand

Background

To evaluate the effectiveness of intravitreal bevacizumab (IVB) and intravitreal ranibizumab (IVR) in actual practice for treating patients with retinal diseases in Thailand.

Methods

A prospective, multi-centre, observational study was conducted among eight hospitals in their ophthalmology outpatient departments. Participants consisted of patients who had previously not received any IVB or IVR treatment between 2013 and 2014. The primary outcome measurement was the change in best-corrected visual acuity (BCVA) at the end of the follow-up period compared to baseline.

Results

There were 1629 treatment-naïve patients for the pro re nata (PRN) treatment pattern and 226 treatment-naive patients for the three-injections (3Inj) treatment pattern. BCVA improvements were found in 35% of the PRN group and 47% of the 3Inj group; however, it was not clinically meaningful between the IVB and IVR groups (P-value = 0.568 for PRN, P-value = 0.103 for 3Inj). A multivariable logistic regression (using the propensity score) showed that positive factors associated with vision improvement for the PRN pattern were the number of drug injections, having retinal vein occlusion, and under 60 years of age, while good BCVA at baseline was a negative predictive factor. For the 3Inj pattern, under 60 years of age and baseline BCVA were statistically significant predictors. Nonetheless, diabetes mellitus (DM) without other comorbidities was a statistically significant predictor of low response to vision improvement compared to DM with other comorbidities.

Conclusions

This study was the first observational, prospective study to evaluate the real-life effectiveness of IVB and IVR in Thailand. The majority of participants who used IVB or IVR showed improvements in BCVA after treatment. Further evaluation such as long-term follow-ups and subsequent comparison of effectiveness between IVB and IVR should be investigated due to the limited sample of IVR patients.

Trial registration

Thai Clinical Trial Registry TCTR20141002001. Registered 02 October 2014 (retrospectively registered).

Real-World Safety of Intravitreal Bevacizumab and Ranibizumab Treatments for Retinal Diseases in Thailand: A Prospective Observational Study

BACKGROUND

There is very limited evidence examining serious systemic adverse events (SSAEs) and post-injection endophthalmitis of intravitreal bevacizumab (IVB) and intravitreal ranibizumab (IVR) treatments in Thailand and low- and middle-income countries. Moreover, findings from the existing trials might have limited generalizability to certain populations and rare SSAEs.

OBJECTIVES

This prospective observational study aimed to assess and compare the safety profiles of IVB and IVR in patients with retinal diseases in Thailand.

METHODS

Between 2013 and 2015, 6354 patients eligible for IVB or IVR were recruited from eight hospitals. Main outcomes measures were prevalence and risk of SSAEs, mortality, and endophthalmitis during the 6-month follow-up period.

RESULTS

In the IVB and IVR groups, 94 and 6% of patients participated, respectively. The rates of outcomes in the IVB group were slightly greater than in the IVR group. All-cause mortality rates in the IVB and IVR groups were 1.10 and 0.53%, respectively. Prevalence rates of endophthalmitis and non-fatal strokes in the IVB group were 0.04% of 16,421 injections and 0.27% of 5975 patients, respectively, whereas none of these events were identified in the IVR group. There were no differences between the two groups in the risks of mortality, arteriothrombotic events (ATE), and non-fatal heart failure (HF). Adjustment for potential confounding factors and selection bias using multivariable models for time-to-event outcomes and propensity scores did not alter the results.

CONCLUSIONS

The rates of SAEs in both groups were low. The IVB and IVR treatments were not associated with significant risks of mortality, ATE, and non-fatal HF.

TRIAL REGISTRATION

Thai Clinical Trial Registry identifier TCTR20141002001.

Comparative efficacy of bevacizumab, ranibizumab, and aflibercept for treatment of macular edema secondary to retinal vein occlusion: a systematic review and network meta-analysis

INTRODUCTION

Anti-vascular endothelial growth factor (VEGF) therapy has become the most commonly used treatment for macular edema secondary to retinal vein occlusion (RVO). Although its superior efficacy as compared to other interventions has been proven, there is a lack of evidence for relative efficacy among anti-VEGF drugs. Areas covered: This work systematically reviewed and compared the efficacy of intravitreal bevacizumab, ranibizumab, and aflibercept for treating macular edema due to RVO. PubMed, EMBASE, and the Cochrane Library were searched from their inception until October 2017. Eleven randomized controlled trials (18 articles; 1830 adult patients) were identified. The proportion of patients who gained at least 15 letters in best-corrected visual acuity (BCVA), mean change from baseline in BCVA, and mean change from baseline in central macular thickness (CMT) were reported and these efficacy outcomes at 6 months were analyzed in network meta-analysis. Expert commentary: Apparently, bevacizumab, ranibizumab, and aflibercept were significantly superior to sham injection in terms of BCVA improvement and CMT reduction and had good safety profiles. However, there were no statistically significant differences in any outcomes among anti-VEGF drugs. In selecting an anti-VEGF drug for individual patients, other factors including affordability, drug availability, and patient characteristics should be considered.

Intravitreal Bevacizumab in Diabetic Retinopathy. Recommendations from the Pan-American Collaborative Retina Study Group (PACORES): The 2016 Knobloch Lecture

The advent of intravitreal anti-vascular endothelial growth factor (anti-VEGF) medications has revolutionized the treatment of diabetic eye diseases. Herein, we report the outcomes of clinical studies carried out by the Pan-American Collaborative Retina Study Group (PACORES), with a specific focus on the efficacy of intravitreal bevacizumab in the management of diabetic macular edema and proliferative diabetic retinopathy. We will also discuss the use of intravitreal bevacizumab as a preoperative, adjuvant therapy before vitrectomy for proliferative diabetic retinopathy.

Ethical Off-label Drug use: Need for a Rethink?

Off-label drug use is unavoidable, especially in children. Legal justice originates from ethical justice; therefore, ethical off-label drug use can be considered legal. We share our successful experiences with this issue in China, which may provide a reference to Indian healthcare professionals, to develop a common executable standard to be applied to evaluate the off-label drug use in clinical practice.

INTRAVITREAL BEVACIZUMAB FOR CHOROIDAL NEOVASCULARIZATION IN AGE-RELATED MACULAR DEGENERATION: 5-Year Results of The Pan-American Collaborative Retina Study Group

PURPOSE

To report the long-term anatomical and functional outcomes of patients with choroidal neovascularization secondary to age-related macular degeneration treated with intravitreal bevacizumab (IVB).

METHODS

Retrospective case series. Patients diagnosed with subfoveal choroidal neovascularization secondary to age-related macular degeneration that were treated with at least 1 intravitreal injection of 1.25 mg of IVB and had a minimum follow-up of 60 months. Patients underwent best-corrected Snellen visual acuity testing, optical coherence tomography, and ophthalmoscopic examination at baseline and follow-up visits.

RESULTS

Two hundred and forty-seven consecutive patients (292 eyes) were included. The mean number of IVB injections per eye was 10.9 ± 6.4. At 5 years, the BCVA decreased from 20/150 (logMAR 0.9 ± 0.6) at baseline to 20/250 (logMAR 1.1 ± 0.7) (P = <0.0001). The mean CMT decreased from 343.1+ 122.3 μm at baseline to 314.7 ± 128.8 μm at 60 months of follow-up (P = 0.009). Geographic atrophy (GA) was observed at baseline in 47 (16%) of 292 eyes. By 5 years, GA developed or progressed in 124 (42.5%) of 292 eyes (P < 0.0001).

CONCLUSION

The early visual gains obtained from IVB were not maintained at 5 years of follow-up. In addition, IVB may play a role in the development or progression of GA.

Intravitreal bevacizumab for diabetic macular oedema: 5-year results of the Pan-American Collaborative Retina Study group

BACKGROUND/AIMS

To report the long-term anatomical and functional outcomes of patients with centre-involved diabetic macular oedema (DME) treated with intravitreal bevacizumab (IVB).

METHODS

Retrospective case series. Patients diagnosed with centre-involved DME that were treated with at least one injection of 1.25 mg IVB and had a minimum follow-up of 60 months. Patients underwent measurement of best-corrected visual acuity (BCVA), ophthalmoscopy, optical coherence tomography and fluorescein angiography at baseline, 6-month, 12-month, 24-month, 36-month, 48-month and 60-month visits. The paired samples t test was used to compare the central macular thickness (CMT) and BCVA with baseline values. Statistical significance was indicated by p<0.05.

RESULTS

Two hundred and one consecutive patients (296 eyes) were included. The mean number of IVB injections per eye was 8.4±7.1 (range: 1-47 injections). At 5 years, the BCVA remained stable at 20/100 (logarithm of the minimum angle of resolution=0.7±0.4). Eighty-six (29%) eyes improved ≥2 lines of BCVA, 129 (43.6%) eyes remained stable and 81 (27.4%) eyes lost ≥2 lines of BCVA at 60 months. Mean CMT decreased from 403.5±142.2 μm at baseline to 313.7±117.7 μm over 5 years follow-up (p≤0.0001).

CONCLUSIONS

The early visual gains due to IVB were not maintained 5 years after treatment.

Statin therapy in patients with acute coronary syndrome: low-density lipoprotein cholesterol goal attainment and effect of statin potency

Background

Elevated low-density lipoprotein cholesterol (LDL-C) is associated with an increased risk of coronary artery disease. Current guidelines recommend an LDL-C target of <70 mg/dL (<1.8 mmol/L) for acute coronary syndrome (ACS) patients, and the first-line treatment to lower lipids is statin therapy. Despite current guidelines and the efficacious lipid-lowering agents available, about half of patients at very high risk, including ACS patients, fail to achieve their LDL-C goal. This study assessed LDL-C goal attainment according to use of high and low potency statins in routine practice in Thailand.

Methods

A retrospective cohort study was performed by retrieving data from medical records and the electronic hospital database for a tertiary care hospital in Thailand between 2009 and 2011. Included were ACS patients treated with statins at baseline and with follow-up of LDL-C levels. Patients were divided into high or low potency statin users, and the proportion reaching the LDL-C goal of <70 mg/dL was determined. A Cox proportional hazard model was applied to determine the relationship between statin potency and LDL-C goal attainment. Propensity score adjustment was used to control for confounding by indication.

Results

Of 396 ACS patients (60% males, mean age 64.3±11.6 years), 229 (58%) were treated with high potency statins and 167 (42%) with low potency statins. A quarter reached their target LDL-C goal (25% for patients on high potency statins and 23% on low potency statins). High potency statins were not associated with increased LDL-C goal attainment (adjusted hazards ratio 1.22, 95% confidence interval 0.79–1.88; P=0.363).

Conclusion

There was no significant effect of high potency statins on LDL-C goal attainment. Moreover, this study showed low LDL-C goal attainment for patients on either low or high potency statins. The reasons for the low LDL-C goal attainment rate warrants further investigation.

Intravitreal bevacizumab for proliferative diabetic retinopathy with new dense vitreous hemorrhage after full panretinal photocoagulation

PURPOSE

To evaluate the efficacy and safety of intravitreal bevacizumab (IVB) injections for the treatment of proliferative diabetic retinopathy (PDR) with new dense vitreous hemorrhage (VH) after previous full panretinal photocoagulation (PRP).

METHODS

Prospective study of consecutive PDR with prior complete PRP patients, who presented with new dense VH, were treated with IVB injection. Complete ophthalmic examination and/or ocular ultrasonography were performed at baseline and 1, 6, and 12 weeks and 6, 9, and 12 months after the first injection. Reinjection was done in non-clearing and recurrent VH.

RESULTS

Eighteen eyes of 18 patients, mean age 47.7 ± 12.69 years were included. In all, 14 (77.78%) patients had type 2 diabetes mellitus. Systemic hypertension and dyslipidemia were the most common systemic diseases. All cases were phakic eye with previous complete PRP. Patients received 1.6 ± 0.42 intravitreal injections over a 12-month period. VH cleared completely in 7 (38.89%), 9 (50%), and 13 (72.22%) eyes after 6 weeks, 6 months, and 12 months, respectively. Re-bleeding, however, occurred in 10 (56%) eyes during the follow-up period, and 5 (28%) eyes still had residual VH at the last visit. Statistically significant visual gain was observed in 9 (50%) eyes. Unfortunately, 2 (11%) eyes had severe visual loss because of the tractional retinal detachment (TRD). Mild ocular complication was detected in one patient.

CONCLUSION

IVB injection had good efficacy and safety for treatment of new VH in patients with PDR and prior complete PRP. This procedure may be especially relevant for diabetic patients at high-risk for surgical intervention.