012 The use of tumour necrosis factor inhibitors in disease modifying anti rheumatic drug-resistant inflammatory monoarthritis of the knee

Abstract

Background: Tumour necrosis factor (TNF) inhibitors are effective in the management of peripheral arthritis in patients with inflammatory arthritis. There is a lack of evidence available regarding the efficacy of TNF inhibitors in patients with inflammatory monoarthritis of the knee resistant to disease modifying antirheumatic drugs (DMARDs). A limited number of studies have assessed specifically the response to TNF inhibitor in knee synovitis. These have been in the setting of a peripheral spondyloarthritis with many of the patients having an oligoarthritis which included knee synovitis. We present two case reports reviewing the efficacy of TNF inhibitor treatment in inflammatory monoarthritis of the knee, following successful individual funding request (IFR) approval for the use of etanercept. IFR approval can be challenging with limited evidence for the use of TNF inhibitors in this setting. Methods: Patient 1: 37-year-old female presented with right knee inflammatory monoarthritis at 34 years of age. She had no history of psoriasis, inflammatory bowel disease, iritis and had no other joint or spinal symptoms. Both sulfasalazine and hydroxychloroquine treatment was ineffective, methotrexate was stopped prior to conception and she was unable to tolerate steroid injections due to severe facial flushing. 12 months prior to initiation of etanercept in January 2016, the patient received three local steroid injections, but continued with persistent synovitis. An IFR was approved for the use of etanercept. Patient 2: 28-year-old male, presenting with inflammatory monoarthritis of the right knee at the age of 21. He had no history of psoriasis, inflammatory bowel disease, iritis and had no other joint or spinal symptoms. He was initially treated with intermittent steroid injections and subsequently started sulfasalazine and methotrexate combination treatment. Methotrexate was stopped due to persistent elevations in alanine transaminase (ALT) and intolerance due to nausea and sulphasalazine was ineffective. 12 months prior to initiation of etanercept in October 2016, he received three local steroid injections, but continued with persistent synovitis. An IFR was approved for the use of etanercept. Results: Patient 1: Response to etanercept was assessed at three months. On review, she showed no signs of synovitis and she has now been in clinical remission for 16 months. Patient 2: The response to etanercept was assessed at three months, with the patient showing no signs of synovitis, settled symptoms and has now been in clinical remission for 10 months. Conclusion: Currently funding approval for TNF inhibitors in DMARD resistant inflammatory monoarthritis of the knee can be challenging and limited evidence to support its use adds to the difficulty. These cases provide support that TNF inhibitors can be effective in patients who are resistant to DMARDs for the treatment of inflammatory monoarthritis of the knee and allow them to achieve clinical remission.