Safety monitoring of ophthalmic biologics: a systematic review of pre- and postmarketing safety data

International Classification System for Ocular Complications of Anti-VEGF Agents in Clinical Trials

PURPOSE

Complications associated with intravitreal anti-VEGF therapies are reported inconsistently in the literature, thus limiting an accurate evaluation and comparison of safety between studies. This study aimed to develop a standardized classification system for anti-VEGF ocular complications using the Delphi consensus process.

DESIGN

Systematic review and Delphi consensus process.

PARTICIPANTS

Twenty-five international retinal specialists participated in the Delphi consensus survey.

METHODS

A systematic literature search was conducted to identify complications of intravitreal anti-VEGF agent administration based on randomized controlled trials (RCTs) of anti-VEGF therapy. A comprehensive list of complications was derived from these studies, and this list was subjected to iterative Delphi consensus surveys involving international retinal specialists who voted on inclusion, exclusion, rephrasing, and addition of complications. Furthermore, surveys determined specifiers for the selected complications. This iterative process helped to refine the final classification system.

MAIN OUTCOME MEASURES

The proportion of retinal specialists who choose to include or exclude complications associated with anti-VEGF administration.

RESULTS

After screening 18 229 articles, 130 complications were categorized from 145 included RCTs. Participant consensus via the Delphi method resulted in the inclusion of 91 complications (70%) after 3 rounds. After incorporating further modifications made based on participant suggestions, such as rewording certain phrases and combining similar terms, 24 redundant complications were removed, leaving a total of 67 complications (52%) in the final list. A total of 14 complications (11%) met exclusion thresholds and were eliminated by participants across both rounds. All other remaining complications not meeting inclusion or exclusion thresholds also were excluded from the final classification system after the Delphi process terminated. In addition, 47 of 75 proposed complication specifiers (63%) were included based on participant agreement.

CONCLUSIONS

Using the Delphi consensus process, a comprehensive, standardized classification system consisting of 67 ocular complications and 47 unique specifiers was established for intravitreal anti-VEGF agents in clinical trials. The adoption of this system in future trials could improve consistency and quality of adverse event reporting, potentially facilitating more accurate risk-benefit analyses.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Adverse Drug Reactions and Toxicity of the Food and Drug Administration-Approved Antisense Oligonucleotide Drugs

The market for large molecule biologic drugs has grown rapidly, including antisense oligonucleotide (ASO) drugs. ASO drugs work as single-stranded synthetic oligonucleotides that reduce production or alter functions of disease-causing proteins through various mechanisms, such as mRNA degradation, exon skipping, and ASO-protein interactions. Since the first ASO drug, fomivirsen, was approved in 1998, the U.S. Food and Drug Administration (FDA) has approved 10 ASO drugs to date. Although ASO drugs are efficacious in treating some diseases that are untargetable by small-molecule chemical drugs, concerns on adverse drug reactions (ADRs) and toxicity cannot be ignored. Illustrative of this, mipomersen was recently taken off the market due to its hepatotoxicity risk. This paper reviews ADRs and toxicity from FDA drug labeling, preclinical studies, clinical trials, and postmarketing real-world studies on the 10 FDA-approved ASO drugs, including fomivirsen and pegaptanib, mipomersen, nusinersen, inotersen, defibrotide, eteplirsen, golodirsen, viltolarsen, and casimersen. Unique and common ADRs and toxicity for each ASO drug are summarized here. The risk of developing hepatotoxicity, kidney toxicity, and hypersensitivity reactions co-exists for multiple ASO drugs. Special precautions need to be in place when certain ASO drugs are administrated. Further discussion is extended on studying the mechanisms of ADRs and toxicity of these drugs, evaluating the existing physiologic and pathologic states of patients, optimizing the dose and route of administration, and formulating personalized treatment plans to improve the clinical utility of FDA-approved ASO drugs and discovery and development of new ASO drugs with reduced ADRs. SIGNIFICANCE STATEMENT: The current review provides a comprehensive analysis of unique and common ADRs and the toxicity of FDA-approved ASO drugs. The information can help better manage the risk of severe hepatotoxicity, kidney toxicity, and hypersensitivity reactions in the usage of currently approved ASO drugs and the discovery and development of new and safer ASO drugs.

Intravitreal ranibizumab versus aflibercept versus bevacizumab for macular oedema due to central retinal vein occlusion: the LEAVO non-inferiority three-arm RCT

BACKGROUND

Licensed ranibizumab (0.5 mg/0.05 ml Lucentis®; Novartis International AG, Basel, Switzerland) and aflibercept (2 mg/0.05 ml Eylea®; Bayer AG, Leverkusen, Germany) and unlicensed bevacizumab (1.25 mg/0.05 ml Avastin®; F. Hoffmann-La Roche AG, Basel, Switzerland) are used to treat macula oedema due to central retinal vein occlusion, but their relative clinical effectiveness, cost-effectiveness and impact on the UK NHS and Personal Social Services have never been directly compared over the typical disease treatment period.

OBJECTIVE

The objective was to compare the clinical effectiveness and cost-effectiveness of three intravitreal antivascular endothelial growth factor agents for the management of macula oedema due to central retinal vein occlusion.

DESIGN

This was a three-arm, double-masked, randomised controlled non-inferiority trial.

SETTING

The trial was set in 44 UK NHS ophthalmology departments, between 2014 and 2018.

PARTICIPANTS

A total of 463 patients with visual impairment due to macula oedema secondary to central retinal vein occlusion were included in the trial.

INTERVENTIONS

The participants were treated with repeated intravitreal injections of ranibizumab (n = 155), aflibercept (n = 154) or bevacizumab (n = 154).

MAIN OUTCOME MEASURES

The primary outcome was an increase in the best corrected visual acuity letter score from baseline to 100 weeks in the trial eye. The null hypothesis that aflibercept and bevacizumab are each inferior to ranibizumab was tested with a non-inferiority margin of -5 visual acuity letters over 100 weeks. Secondary outcomes included additional visual acuity, and imaging outcomes, Visual Function Questionnaire-25, EuroQol-5 Dimensions with and without a vision bolt-on, and drug side effects. Cost-effectiveness was estimated using treatment costs and Visual Function Questionnaire-Utility Index to measure quality-adjusted life-years.

RESULTS

The adjusted mean changes at 100 weeks in the best corrected visual acuity letter scores were as follows - ranibizumab, 12.5 letters (standard deviation 21.1 letters); aflibercept, 15.1 letters (standard deviation 18.7 letters); and bevacizumab, 9.8 letters (standard deviation 21.4 letters). Aflibercept was non-inferior to ranibizumab in the intention-to-treat population (adjusted mean best corrected visual acuity difference 2.23 letters, 95% confidence interval -2.17 to 6.63 letters; p = 0.0006), but not superior. The study was unable to demonstrate that bevacizumab was non-inferior to ranibizumab in the intention-to-treat population (adjusted mean best corrected visual acuity difference -1.73 letters, 95% confidence interval -6.12 to 2.67 letters; p = 0.071). A post hoc analysis was unable to demonstrate that bevacizumab was non-inferior to aflibercept in the intention-to-treat population (adjusted mean best corrected visual acuity difference was -3.96 letters, 95% confidence interval -8.34 to 0.42 letters; p = 0.32). All per-protocol population results were the same. Fewer injections were required with aflibercept (10.0) than with ranibizumab (11.8) (difference in means -1.8, 95% confidence interval -2.9 to -0.8). A post hoc analysis showed that more bevacizumab than aflibercept injections were required (difference in means 1.6, 95% confidence interval 0.5 to 2.7). There were no new safety concerns. The model- and trial-based cost-effectiveness analyses estimated that bevacizumab was the most cost-effective treatment at a threshold of £20,000-30,000 per quality-adjusted life-year.

LIMITATIONS

The comparison of aflibercept and bevacizumab was a post hoc analysis.

CONCLUSION

The study showed aflibercept to be non-inferior to ranibizumab. However, the possibility that bevacizumab is worse than ranibizumab and aflibercept by 5 visual acuity letters cannot be ruled out. Bevacizumab is an economically attractive treatment alternative and would lead to substantial cost savings to the NHS and other health-care systems. However, uncertainty about its relative effectiveness should be discussed comprehensively with patients, their representatives and funders before treatment is considered.

FUTURE WORK

To obtain extensive patient feedback and discuss with all stakeholders future bevacizumab NHS use.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN13623634.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 25, No. 38. See the NIHR Journals Library website for further project information.

Safety and efficacy of Razumab™ (world's first biosimilar ranibizumab) in wet age-related macular degeneration: a post-marketing, prospective ASSET study

BACKGROUND

Razumab™ (world's first biosimilar ranibizumab) is approved for several macular disorders including wet age-related macular degeneration (AMD). We evaluated the safety and efficacy of biosimilar ranibizumab in wet AMD.

METHODS

This prospective, multicentre, rAnibizumab bioSimilar Safety Efficacy postmarkeTing (ASSET) study enrolled patients aged ≥ 50 years with wet AMD having best-corrected visual acuity (BCVA) between 20/40 and 20/320. The patients received intravitreal biosimilar ranibizumab 0.5 mg every 4 weeks for 24 weeks. Safety endpoints included the incidence of adverse events (AEs), serious AEs (SAEs), and immunoreactivity after 6 months. The efficacy endpoints were the proportion of patients who lose fewer than 15 letters, increase in BCVA, change in central retinal thickness (CRT), and change in Visual Function Questionnaire-25 (VFQ-25) score, from baseline to 24 weeks.

RESULTS

Of the 126 enrolled patients, majority (95.24%) of the patients received all 6 doses of biosimilar ranibizumab (total 3 mg). Nineteen AEs were reported (n = 16; 12.7%); majority (78.9%) were mild. There were no serious AEs reported, except one AE of death which was unrelated to the study drug. None of the patients discontinued the study due to an AE. The most common ocular AE was increase in intraocular pressure (4 events) and non-ocular AE was pyrexia (5 events). A total of 7.9% (10/126) patients prior to dosing and 7.1% (9/126) patients post-treatment were positive for anti-ranibizumab antibodies. No AEs suggestive of immunogenicity were noted. At 24-weeks, 97.60% patients in the intent-to-treat (ITT) population (N = 125) and 97.41% patients in the per-protocol (PP) population (N = 116) lost < 15 letters from baseline visual acuity. In the ITT and PP populations, 31.20% and 32.76% patients, respectively, showed improved visual acuity by ≥ 15 letters. Significant improvements in BCVA (mean difference: 8.8, 9.2, p < 0.001 for ITT, PP) and VFQ-25 (8.5, 9.2, p < 0.001 for ITT, PP) were seen; CRT reduced significantly (125 µm, 119.3 µm, p < 0.001 for ITT, PP).

CONCLUSION

Razumab™ (world's first biosimilar ranibizumab) was well-tolerated without new safety concerns and significantly improved visual acuity in wet AMD patients. Trial registration CTRI/2016/03/006739. Registered 18 March 2016-Prospectively registered, http://ctri.nic.in/Clinicaltrials/pmaindet2.php?trialid=13141&EncHid=&userName=2016/03/006739.

Keratocytes promote corneal neovascularization through VEGFr3 induced by PPARα-inhibition

As the peroxisome proliferator - activated receptor alpha (PPARα) agonist, fenofibrate has been widely used to be a good lipid-regulating drug in the clinical application. In this study, we investigated the mechanism by which keratocytes inhibit the corneal neovascularization (CNV) through PPARα - activation. To do this, the CNV model was established by alkali burn, followed by being divided into three groups including control, fenofibrate and vehicle group. The expression of VEGFr3, MMP13 and PPARα in corneas of normal mouse and alkali-burned mouse was determined via quantitative RT- PCR (qRT-PCR) and Western blot analysis (WB). The CNV area was observed under a slit lamp microscope. The location of PPARα expression in the corneas was determined via immunohistochemistry. In cultured primary keratocytes, the effect of fenofibrate on PPARα, VEGFr3 and MMP13 expression was determined by qRT-PCR and WB. Besides, PPARα knockout (PPARα-/-) mouse CNV and keratocytes model were established to further confirm the effect of PPARα on VEGFr3 and MMP13 expression. We found that PPARα was expressed in epithelium, stroma and endothelium of the normal cornea, however, with relatively low level in the corneal stroma. Meanwhile, its expression was decreased markedly in the cornea during the stage of CNV formation. After treatment of fenofibrate, PPARα expression was promoted and the expression of VEGFr3 and MMP13 was inhibited in both CNV mice model and primary keratocytes, and CNV areas were decreased in CNV mice model. However, the results in PPARα-/- CNV and keratocytes model were opposite. Our results suggest that keratocytes could promote the expression of VEGFr3 and MMP13, and CNV formation through PPARα downregulation.

A comparison between two recommendations to conduct and report systematic reviews on drug's safety

BACKGROUND

Several recommendations are available to conduct and report a systematic review of adverse drug reactions. This study is aimed at identifying and comparing the methodologies of the two most commonly used recommendations to conduct and report systematic reviews on drug's safety.

METHODS

Two systematic reviews were conducted following the recommendations "Cochrane Handbook for Systematic Reviews of Interventions" and "Systematic Reviews' Centre for Reviews and Dissemination guidance for undertaking reviews in healthcare." The methods of each recommendation were characterized, and the results and the discussion of each systematic review were also evaluated.

RESULTS

The methodologies of both recommendations are similar. The review question was structured. Both recommendations suggest to include pre- and post-marketing data. The recommended data sources differed and, consequently, the results of the systematic reviews (37 vs. 35 studies). Other aspects of search literature were identical. Different tools are suggested to evaluate the methodological quality of the included studies. For case reports, both recommendations only report some questions that may be helpful to assess risk of bias. The reporting of the results and discussion is also identical for both recommendations.

CONCLUSIONS

Few methodological differences were observed between the analyzed recommendations to conduct a systematic review on drug's safety. Combining their methods into a single and recognized recommendation could be of great value.

Appraising the Quality of Systematic Reviews for Age-Related Macular Degeneration Interventions: A Systematic Review

Importance

Age-related macular degeneration (AMD) is a leading cause of vision impairment. It is imperative that AMD care is timely, appropriate, and evidence-based. It is thus essential that AMD systematic reviews are robust; however, little is known about the quality of this literature.

Objectives

To investigate the methodological quality of systematic reviews of AMD intervention studies, and to evaluate their use for guiding evidence-based care.

Evidence Review

This systematic review adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. All studies that self-identified as a systematic review in their title or abstract or were categorized as a systematic review from a medical subject heading and investigated the safety, efficacy and/or effectiveness of an AMD intervention were included. Comprehensive electronic searches were performed in Ovid MEDLINE, Embase, and the Cochrane Library from inception to March 2017. Two reviewers independently assessed titles and abstracts, then full-texts for eligibility. Quality was assessed using the Assessing the Methodological Quality of Systematic Reviews (AMSTAR) tool. Study characteristics (publication year, type of intervention, journal, citation rate, and funding source) were extracted.

Findings

Of 983 citations retrieved, 71 studies (7.6%) were deemed eligible. The first systematic review relating to an AMD intervention was published in 2003. More than half were published since 2014. Methodological quality was highly variable. The mean (SD) AMSTAR score was 5.8 (3.2) of 11.0, with no significant improvement over time (r = -0.03; 95% CI, -0.26 to 0.21; P = .83). Cochrane systematic reviews were overall of higher quality than reviews in other journals (mean [SD] AMSTAR score, 9.9 [1.2], n = 15 vs 4.7 [2.2], n = 56; P < .001). Overall, there was poor adherence to referring to an a priori design (22 articles [31%]) and reporting conflicts of interest in both the review and included studies (16 articles [23%]). Reviews funded by government grants and/or institutions were generally of higher quality than industry-sponsored reviews or where the funding source was not reported.

Conclusions and Relevance

There are gaps in the conduct of systematic reviews in the field of AMD. Enhanced endorsement of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement by refereed journals may improve review quality and improve the dissemination of reliable evidence relating to AMD interventions to clinicians.

Ranibizumab and digital ischemia

Case report of a patient with age-related macular degeneration whose digital ischemia can most plausibly be attributed to ranibizumab.

PURPOSE

To report ranibizumab as the probable cause of digital ischemia in a patient treated for age-related macular degeneration.

METHODS

Single-patient case report.

RESULTS

An 83-year-old woman with an unremarkable medical history suffered acute ischemia in her left hand with necrosis of the distal phalange of the fifth finger after six intravitreal injections of ranibizumab. Her etiological work-up was negative. Her condition improved after endovascular revascularization and remained good at six months' follow-up after three months of dual antithrombotic therapy (low molecular weight heparin then rivaroxaban, both with aspirin) followed by rivaroxaban alone and four courses of intravenous iloprost.

CONCLUSION

The increased incidence of peripheral arterial thromboembolic events in patients under ranibizumab treatment is slight but significant, with 0.8-5% of patients affected, most of which suffer strokes. These events seem to occur at a random time after ranibizumab treatment is initiated and no reliable marker has yet been identified. The most probable cause of digital ischemia in our patient was ranibizumab.

Comparative Study of In Situ Loaded Antibody and PEG-Fab NIPAAM Gels

Hydrogels can potentially prolong the release of a therapeutic protein, especially to treat blinding conditions. One challenge is to ensure that the protein and hydrogel are intimately mixed by better protein entanglement within the hydrogel. N-isopropylacrylamide (NIPAAM) gels are optimized with poly(ethylene glycol) diacrylate (PEDGA) crosslinker in the presence of either bevacizumab or PEG conjugated ranibizumab (PEG₁₀ -Fab_rani ). The release profiles of the hydrogels are evaluated using an outflow model of the eye, which is previously validated for human clearance of proteins. Release kinetics of in situ loaded bevacizumab-NIPAAM gels displays a prolonged bimodal release profile in phosphate buffered saline compared to bevacizumab loaded into a preformed NIPAAM gel. Bevacizumab release in simulated vitreous from in situ loaded gels is similar to bevacizumab control indicating that diffusion through the vitreous rather than from the gel is rate limiting. Ranibizumab is site-specifically PEGylated by disulfide rebridging conjugation. Prolonged and continuous release is observed with the in situ loaded PEG₁₀ -Fab_rani -NIPAAM gels compared to PEG₁₀ -Fab_rani injection (control). Compared to an unmodified protein, there is better mixing due to PEG entanglement and compatibility of PEG₁₀ -Fab_rani within the NIPAAM-PEDGA hydrogel. These encouraging results suggest that the extended release of PEGylated proteins in the vitreous can be achieved using injectable hydrogels.

Principles of pharmacology in the eye

The eye is a highly specialized organ that is subject to a huge range of pathology. Both local and systemic disease may affect different anatomical regions of the eye. The least invasive routes for ocular drug administration are topical (e.g. eye drops) and systemic (e.g. tablets) formulations. Barriers that subserve as protection against pathogen entry also restrict drug permeation. Topically administered drugs often display limited bioavailability due to many physical and biochemical barriers including the pre-corneal tear film, the structure and biophysiological properties of the cornea, the limited volume that can be accommodated by the cul-de-sac, the lacrimal drainage system and reflex tearing. The tissue layers of the cornea and conjunctiva are further key factors that act to restrict drug delivery. Using carriers that enhance viscosity or bind to the ocular surface increases bioavailability. Matching the pH and polarity of drug molecules to the tissue layers allows greater penetration. Drug delivery to the posterior segment is a greater challenge and, currently, the standard route is via intravitreal injection, notwithstanding the risks of endophthalmitis and retinal detachment with frequent injections. Intraocular implants that allow sustained drug release are at different stages of development. Novel exciting therapeutic approaches include methods for promoting transscleral delivery, sustained release devices, nanotechnology and gene therapy.

EFFECT OF PEGAPTANIB AND RANIBIZUMAB ON PLASMA AND VITREOUS HOMOCYSTEINE IN PATIENTS WITH EXUDATIVE AGE-RELATED MACULAR DEGENERATION

PURPOSE

To investigate homocysteine (Hcy) concentration in the blood plasma and the vitreous in patients with exudative age-related macular degeneration receiving intravitreal anti-vascular endothelial growth factor therapy.

METHODS

Plasma Hcy and vitreous Hcy levels were analyzed in 73 exudative age-related macular degeneration patients (50.7% received pegaptanib 0.3 mg and 50.3% received ranibizumab 0.5 mg) and compared with 80 controls and 40 patients with idiopathic epiretinal membranes, respectively. Homocysteine concentration was measured by immunonephelometric particle test, and it was determined before and after antiangiogenic therapy.

RESULTS

The mean Hcy concentrations (± SD) of blood plasma and vitreous were 13.0 ± 4.2 μmol/L and 1.00 ± 0.3 μmol/L in patients treated with pegaptanib; in ranibizumab group, they were 12.8 ± 2.5 μmol/L and 1.4 ± 0.6 μmol/L, respectively. The results of plasma and vitreous Hcy indicated statistically significant differences between exudative age-related macular degeneration patients and control groups (P = 0.03 and P = 0.02). After 6 months with both intravitreal therapies, the plasma and vitreous Hcy concentrations did not change significantly (P = 0.1).

CONCLUSION

Pegaptanib and ranibizumab did not increase the plasma or vitreous Hcy concentrations.

Safety of monoclonal antibodies and related therapeutic proteins for the treatment of neovascular macular degeneration: addressing outstanding issues

INTRODUCTION

The vascular endothelial growth factor (VEGF) inhibitors most widely used to treat neovascular age-dependent macular degeneration (nAMD) are different proteins with structural features potentially relevant to adverse effects (AEs). Two of these are also established in cancer therapy (with higher dosages and AEs). The importance of ocular AE and extraocular activities is still a subject of controversy and ongoing research.

AREAS COVERED

Potential risks of intraocular VEGF inhibition based on prospective studies, in vitro investigations, pharmacokinetics, and hints from anti-cancer treatment.

EXPERT OPINION

nAMD is a frequently observed chronic clinical condition severely affecting the visual function of elderly persons. Intravitreal injection of VEGF-inactivating proteins is highly effective to prevent loss of vision. Anti-VEGF therapy is well tolerated, and low rates of ocular and systemic AEs in smaller trials suggest a very high benefit/risk ratio. The proteins established in nAMD therapy show similar efficacies. In the controversy over the off-label use of bevacizumab purely on grounds of much lower cost, the small, but potentially relevant differences between the available drugs are easily either dramatized (by pharmaceutical companies) or trivialized (by health insurances) and even political interference is involved. Facing the lack of a convincing body of evidence regarding safety, further long-term study results seem necessary.

The PK-Eye: A Novel In Vitro Ocular Flow Model for Use in Preclinical Drug Development

A 2-compartment in vitro eye flow model has been developed to estimate ocular drug clearance by the anterior aqueous outflow pathway. The model is designed to accelerate the development of longer-acting ophthalmic therapeutics. Dye studies show aqueous flow is necessary for a molecule injected into the vitreous cavity to clear from the model. The clearance times of proteins can be estimated by collecting the aqueous outflow, which was first conducted with bevacizumab using phosphate-buffered saline in the vitreous cavity. A simulated vitreous solution was then used and ranibizumab (0.5 mg) displayed a clearance time of 8.1 ± 3.1 days, which is comparable to that observed in humans. The model can estimate drug release from implants or the dissolution of suspensions as a first step in their clearance mechanism, which will be the rate-limiting step for the overall resident time of a candidate dosage form in the vitreous. A suspension of triamcinolone acetonide (Kenalog®) (4.0 mg) displayed clearance times spanning 26-28 days. These results indicate that the model can be used to determine in vitro-in vivo correlations in preclinical studies to develop long-lasting therapeutics to treat blinding diseases at the back of the eye.