Clinical Trial: Vaccine Response After Rituximab for Chronic, Severe Idiopathic Thrombocytopenic Purpura

Study Status: Completed
Recruit Status: Completed
Study Type: Interventional

Official Title: Vaccine Response After Rituximab for Chronic, Severe Idiopathic Thrombocytopenic Purpura (ITP)

Brief Summary: The purpose of this study is to determine how children with a history of severe, chronic Idiopathic Thrombocytopenic Purpura (ITP) who were treated with rituximab might respond to vaccines. Eligible patients are previously or currently enrolled in a study entitled "Open Label, Phase I/II Trial of Rituximab for Chronic, Severe Idiopathic Thrombocytopenic Purpura in Children and Adolescents" and have decided to obtain an inactivated influenza vaccination. These patients will be invited to provide one blood sample prior to vaccination and a second sample following vaccination to quantify immune response to vaccination.

Detailed Summary:

The purpose of this ancillary, pilot-phase study is to determine how children with a history of severe, chronic ITP who were treated with rituximab might respond to vaccines. Eligible patients are previously or currently enrolled in a study entitled "Open Label, Phase I/II Trial of Rituximab for Chronic, Severe Idiopathic Thrombocytopenic Purpura in Children and Adolescents" (CHB 02-12-160) and have decided to obtain the trivalent, inactivated influenza vaccination. These patients will be invited to provide one blood sample prior to vaccination and a second sample 4-8 weeks after vaccination to quantify immune response to vaccination. Additionally, if patients are scheduled to receive a tetanus booster vaccination within one month before or after the influenza vaccination, response to tetanus will also be quantified. This sample will be collected during the same phlebotomy as the influenza sample. In some cases, a blood sample was stored prior to rituximab treatment and will be used for baseline assessment. The primary and secondary objectives for this study are as follows:

Primary:

  • To determine the portion of patients who will respond adequately to influenza vaccination, with adequacy defined as a titer greater than 1:32 for each strain of virus in the vaccine, measured 4-8 weeks after administration of the vaccine OR greater than a four-fold increase in titers measured 4-8 weeks after administration of the vaccine

Secondary Objectives:

  • To evaluate the ability to mount a response to the influenza vaccine, with response defined as any increase in influenza antibody titer for each strain of virus between samples before and 4-8 weeks after vaccina
    Sponsor: Neufeld, Ellis J, MD, PhD

    Current Primary Outcome: The number of patients with a titer greater than 1:32 OR greater than 4-fold increase in titer for each strain of virus in the influenza vaccine at 4-8 weeks after vaccination

    Original Primary Outcome: Same as current

    Current Secondary Outcome:

    • The number of patients with any increase in titer for each strain of virus in the influenza vaccine at 4-8 weeks after vaccination
    • The number of patients with a titer greater than 1:32 OR greater than 4-fold increase in titer for each strain of virus in the tetanus vaccine at 4-8 weeks after vaccination
    • The number of patients with any increase in titer for each strain of virus in the tetanus vaccine at 4-8 weeks after vaccination.


    Original Secondary Outcome: Same as current

    Information By: Neufeld, Ellis J, MD, PhD

    Dates:
    Date Received: October 18, 2012
    Date Started: October 2004
    Date Completion:
    Last Updated: October 24, 2012
    Last Verified: October 2012