{"classes":[{"categories":[{"measurements":[{"groupId":"OG000","value":"0"},{"groupId":"OG001","value":"0"}]}]}],"denoms":[{"counts":[{"groupId":"OG000","value":"3"},{"groupId":"OG001","value":"3"}],"units":"Participants"}],"description":"DLTs = any ≥grade 3 toxicity related to treatment; treatment delays of ≥7 days due to any toxicity related to treatment, with the exception of hepatic transaminases; or alanine and/or aspartate aminotransferase (ALT and/or AST) \\>3\\*upper limit of normal (ULN) with either a total bilirubin \\>2\\*ULN or an international normalized ratio (INR) \\>1.5 related to treatment, or with the appearance of worsening fatigue, nausea, vomiting, right upper quadrant pain or tenderness, fever, rash, or eosinophilia.","groups":[{"description":"Intravenous (IV) infusions of natalizumab 300 mg once every 28 days for 6 months.","id":"OG000","title":"Natalizumab 300 mg"},{"description":"Intravenous (IV) infusions of natalizumab 450 mg once every 28 days for 6 months.","id":"OG001","title":"Natalizumab 450 mg"}],"paramType":"NUMBER","reportingStatus":"POSTED","timeFrame":"Day 1 up to Day 28","title":"Number of Participants With Dose Limiting Toxicities (DLTs)","type":"PRIMARY","unitOfMeasure":"participants"}