P-086 YI Natalizumab for Moderate to Severe Crohnʼs Disease

Abstract

Natalizumab is currently approved as an alternative for the treatment of moderate to severe refractory Crohn’s disease (CD). It has been well documented that natalizumab has serious and potentially fatal side effects that need close monitoring. ENACT and ENCORE trials which lead to natalizumab approval for the treatment of CD lacked the power to detect serious adverse events. Current post marketing data is also limited regarding the drug’s safety profile and clinical response. This study aims to share our non clinical trial experience with natalizumab in Hispanic patients. Data regarding adverse reactions and clinical response to the medication was collected. A retrospective case review of all CD patients treated with natalizumab in our inflammatory bowel disease center in San Juan, Puerto Rico. Demographic data, disease evolution, disease phenotype, years of disease, prior medication use, prior surgeries, serology markers and response to natalizumab were assessed. Reported side effects, hospitalizations, infections, reasons for drug initiation and discontinuation were recorded. Eighteen patients with CD (9 male, median age 29.8 years, range 14–41 years) with median disease duration of 9.1 years were identified. A high proportion had perianal involvement (78%); penetrating phenotype (94%) or prior surgical treatment related to CD (82%). All patients had prior exposure to at least 2 anti-TNF agents. Five patients showed clinical response to therapy and continue to take natalizumab, with only 1 showing complete clinical response. Only 6 patients were treated longer than 12 months. Thirteen patients (72%) were discontinued from treatment due to adverse effects (69%) or no response to therapy (31%). Adverse events were identified in 100% of patients. A total of 50% of patients had a serious adverse event. Although 1 patient was identified as positive for JC virus antibody, no cases of progressive multifocal leukoencephalopathy (PML) were observed. Our study group had very aggressive disease compared to comparable studies in the literature. Our patients had the highest rate of discontinuation, penetrating disease and surgeries per patient. Fistulizing and penetrating disease may predict poor response to natalizumab. Selection of patients to start natalizumab should not be based solely as a last option of treatment in patients with failure to anti TNF treatment or other immunomodulators. Prior to starting treatment other factors such as disease phenotype should be assessed.