{"classes":[{"categories":[{"measurements":[{"groupId":"OG000","value":"2"}]}],"title":"Antibodies to romiplostim"},{"categories":[{"measurements":[{"groupId":"OG000","value":"1"}]}],"title":"Antibodies to TPO"},{"categories":[{"measurements":[{"groupId":"OG000","value":"2"}]}],"title":"Antibodies to TMP"},{"categories":[{"measurements":[{"groupId":"OG000","value":"1"}]}],"title":"Neutralizing antibodies to romiplostim"},{"categories":[{"measurements":[{"groupId":"OG000","value":"0"}]}],"title":"Neutralizing antibodies to TPO"},{"categories":[{"measurements":[{"groupId":"OG000","value":"0"}]}],"title":"Neutralizing antibodies to TMP"}],"denoms":[{"counts":[{"groupId":"OG000","value":"69"}],"units":"Participants"}],"description":"The number of participants who developed antibody formation (defined as negative at baseline and positive at post-baseline, transient or persistent) to romiplostim, endogenous thrombopoietin (eTPO), and thrombopoietin mimetic peptide (TMP, the peptide component of romiplostim) was summarized.","groups":[{"description":"Participants received romiplostim administered weekly by subcutaneous injection during the 12-month treatment period. The starting dose was 1 μg/kg with weekly dose increases in increments of 1 μg/kg/week to a maximum dose of 10 μg/kg to reach a target platelet count of ≥ 50 x 10\\^9/L. At the completion of the 12-month treatment period, participants receiving only romiplostim and with a platelet count ≥ 50 x 10\\^9/L entered the tapering period, during which the romiplostim dose was decreased by 1 µg/kg every 2 weeks, for up to 19 weeks. Participants who had tapered off treatment with romiplostim and whose platelet count dropped below 50 x 10\\^9/L could reinitiate romiplostim for up to 8 weeks.","id":"OG000","title":"Romiplostim"}],"paramType":"NUMBER","populationDescription":"Safety analysis set participants with available results","reportingStatus":"POSTED","timeFrame":"Baseline and at end of treatment (based on response to treatment, this could occur between 12 months and approximately 18 months)","title":"Number of Participants Who Developed Antibodies to Romiplostim","type":"SECONDARY","unitOfMeasure":"participants"}