Abstract
Purpose:
Nonparaneoplastic Autoimmune retinopathy (AIR) is an immune mediated disorder characterized by antiretinal autoantibodies and progressive vision loss in the absence of malignancy. Rituximab is a chimeric monoclonal antibody which binds specifically to CD20 antigen on B lymphocytes. The objective of this study is to investigate the safety and potential efficacy of rituximab treatment for AIR.
Methods:
Five participants with AIR with positive serum antiretinal antibodies, visual field (VF) and electroretinography (ERG) abnormalities enrolled in this prospective,open-label pilot clinical trial. Rituximab is administered as a cycle consisting of two separate rituximab infusions of 1,000 mg each, two weeks apart. Participants with partial or complete treatment success at 6 months were eligible for a second cycle. Treatment success was defined as 25% improvement in ERG or improvement in the VFs according to predefined criteria. Study visits were performed every three months for the study duration of 18 months. The primary outcome was the number of participants who met the definition of treatment success within 6 months. Safety outcomes included the number and severity of adverse events.
Results:
Four of the 5 patients were female, all were Caucasian with a median age of 52 years (range: 41-65). Three of the 5 (60%) patients had associated autoimmune systemic disease. Median visual acuity at enrolment was 84 ETDRS letters in the better eyes and 80 letters in the worse eyes; at 6 months, median vision was 82 and 79 ETDRS letters, respectively. All patients met the primary outcome of partial or complete response to treatment, most achieving stability. However, in most participants, improvement in visual function measures was not clinically significant. All patients tolerated Rituximab infusions well with no serious adverse events attributable to the study drug.
Conclusions:
Autoimmune retinopathy continues to be a poorly defined challenging disease to manage. Rituximab infusions appear safe and are well tolerated among AIR patients, although with modest effect on the visual function. Randomized, masked clinical trials are needed to distinguish the treatment effect from natural history.
Keywords: 466 clinical (human) or epidemiologic studies: treatment/prevention assessment/controlled clinical trials •
688 retina •
555 immunomodulation/immunoregulation