[A safety study of retinal toxicity after serial intravitreal injections of infliximab in rabbits eyes]

A comprehensive review of intravitreal immunosuppressants and biologicals used in ophthalmology

Systemic immunosuppressants and biologicals have been a valuable tool in the treatment of inflammatory diseases and malignancies. The safety profile of these drugs has been debatable, especially in localized systems, such as the eye. This has led to the search for fairly local approaches, such as intravitreal, subconjunctival, and topical route of administration. Immunosuppressants have been used as a second-line drug in patients intolerable to corticosteroids or those who develop multiple recurrences on weaning corticosteroids. Similarly, biologicals have also been used as the next line of therapy, when adequate control of inflammation could not be attained or immunosuppressants were contraindicated to patients. Intravitreal immunosuppressants, such as methotrexate and sirolimus, have been extensively studied in noninfectious posterior uveitis, whereas limited studies have established the efficacy of intravitreal biologicals, such as infliximab and adalimumab. Most of these drugs have shown good safety profile and tolerability in animal studies alone and have not been studied further in human subjects. However, most of the studies in literature are single-case reports or case series which limits the level of evidence. In this comprehensive review, we discuss the mechanism of action, pharmacodynamics, pharmacokinetics, indications, efficacy, and side effects of different intravitreal immunosuppressants and biologicals that have been studied in literature.

MONTHLY INTRAVITREAL INFLIXIMAB IN BEHÇET'S DISEASE ACTIVE POSTERIOR UVEITIS: A Long-Term Safety Study

PURPOSE

To study the safety of extended monthly intravitreal infliximab injections in patients with active posterior uveitis in Behcet's disease.

METHODS

This is a prospective, interventional, noncomparative, open-label, pilot study of 9 monthly intravitreal infliximab injections (1 mg/0.05 mL) for 22 eyes of 16 patients with active posterior uveitis in Behcet's disease. Control of inflammation and visual outcomes were assessed, and ocular complications were monitored during the study period.

RESULTS

Successful treatment was achieved in 7 eyes (35%), and failure was encountered in 13 eyes (65%). Only seven eyes of six patients (35%) had completed the study and achieved complete resolution of inflammation with improved best-corrected visual acuity and no complications. Failure was either because of inability to control the inflammation in nine eyes (45%) or development of exacerbation of inflammation in four eyes (20%). Four eyes developed severe immunological reaction from the drug after first (n = 1), second (n = 2), and third (n = 1) injections and had to discontinue the injections. Kaplan-Meier survival analysis showed that the mean estimated time to failure was 3.3 ± 0.2 months, and all failed eyes required revision of their systemic immunotherapy to control the ocular inflammation.

CONCLUSION

Intravitreal infliximab for active posterior uveitis in Behcet's disease was associated with a high complication rate and failure to control inflammation in most eyes. It should not be considered a substitute to systemic therapy.

INTRAVITREAL INFLIXIMAB IN REFRACTORY UVEITIS IN BEHCET'S DISEASE: A Safety and Efficacy Clinical Study

PURPOSE

To assess the safety and efficacy of intravitreal infliximab (1 mg/0.05 mL) in patients with refractory posterior uveitis in Behcet's disease.

METHODS

Twenty patients were included in this study. Best corrected visual acuity (BCVA), vitreous haze (graded 0-4), vasculitis, retinitis, and papillopathy (presence or absence) were assessed at baseline, Day 1 and Week 2, 4, 6, 8, 12, and 18. Optical coherence tomography (OCT) central foveal thickness, fluorescein angiography, and flash electroretinogram were done at baseline and 4, 12, and 18 weeks.

RESULTS

Mean baseline logMAR BCVA was 0.94 (20/160), had improved significantly by Week 2 to 0.6 (20/80) (P < 0.0001), and reached 0.36 (20/40) by Weeks 18 with three injections (P < 0.0001). Mean central foveal thickness OCT decreased significantly from baseline 361 μm to 180 μm at the end of follow-up (P < 0.0001). Profound decrease in mean vitreous haze gradings from two to 0.2 by the end follow-up (P < 0.05). There was a significant reduction in the number of patients with vasculitis (15 at baseline to 1 weeks at 18 weeks), retinitis (nine at baseline to none at 4 weeks), and papillitis (two at baseline to none at 4 weeks) (P < 0.05). No significant electrophysiological changes or ocular adverse inflammatory reactions were observed during the study period.

CONCLUSION

Intravitreal infliximab appeared to be safe and effective in treating uveitis in Behcet's disease and should be considered as an alternative to systemic therapies.

The effect of disease-modifying antirheumatic drugs on retinal function in the electrophysiological ex vivo model of the isolated perfused vertebrate retina

BACKGROUND

Disease-modifying antirheumatic drugs (DMARDs) have been suggested in the treatment of inflammatory ophthalmological diseases. The aim of the present study was to investigate the effects of these DMARDs on bovine retinal function.

METHODS

Bovine retina preparations were perfused with a standard solution. After recording stable electroretinograms the nutrient solution was substituted by a DMARD medium with varying concentrations of different drugs (etanercept and infliximab) for 30 min. Afterwards b-wave recovery was observed.

RESULTS

Significant decreases in the b-wave amplitude (p < 0.05) were found for etanercept 0.5 mg/ml (p = 0.0022). Infliximab 2 mg/ml (p = 0.1276) did not result in any statistically significant b-wave reduction.

CONCLUSION

The presented data suggest that infliximab might have the better safety profile than etanercept.

Update on intravitreal anti-tumor necrosis factor alpha therapies for ocular disorders

Tumor necrosis factor alpha (TNF-?) is an important pro-inflammatory cytokine associated with a variety of ocular diseases. The currently available TNF-? inhibitors are etanercept, infliximab, adalimumab, golimumab, and certolizumab. Experimental and clinical studies on the intravitreal use of these agents have been reported with etanercept, infliximab, and adalimumab: etanercept has shown limited efficacy in scarce reports; infliximab has been associated with local safety concerns but appears to benefit certain cases; adalimumab has shown no efficacy in cases of age-related macular degeneration (AMD) or diabetic macular edema (DME), but the combination with bevacizumab may be effective in refractory cases of macular diseases. Further preclinical and clinical studies are warranted in order to be able to obtain a more robust conclusion on the use of intravitreal TNF-? inhibitors.