A Chart Review of Rituximab Plus Repeated Cycles of Dexamethasone

Patients with idiopathic thrombocytopenic purpura (ITP) usually respond with an increase in
platelet count after treatment with steroids, but most patients will experience
recurrence.Rituximab has been a useful treatment for patients with recurrent ITP; many
hundreds of patients have been treated. 30-40% of patients will achieve a complete remission
(CR: platelet count >150 x 109/l) with initial treatment. However, most patients will relapse
between 1 and 3 years from initial treatment suggesting that long-term "cures" only occur in
20% of the initial patients. An increased rate of durable CRs is therefore a desirable goal.
One approach would be to use rituximab maintenance; however, this strategy results in long
term B cell suppression. Dexamethasone has also been used to achieve "cure" in ITP,
especially in adults at or near diagnosis. An initial study suggested that approximately 50%
of patients would achieve a long-term response with only one 4-day cycle of high dose (40
mg/day) dexamethasone. A follow up study suggested that 3-4 cycles of dexamethasone would be
better than 1 cycle. Finally, a recent publication suggested that rituximab plus one cycle of
dexamethasone was superior to dexamethasone alone, with a > 50% CR rate at 6 months. Based on
the published activity of rituximab and dexamethasone in this disorder, some patients have
received treatment with combined dexamethasone and rituximab. We will review the data of
those patients who have received more than one course of dexamethasone together with
rituximab for relapsed or refractory ITP in order to determine the response rate, duration of
response, toxicity of the combination, and clinical predictors of response in this group.

Inclusion Criteria:

1. Subjects must be diagnosed with ITP.

2. Subjects must be 3 years old or older

3. Subjects must have a platelet count less than 40,000/uL at initiation of treatment
regimen or inability to discontinue maintenance treatments such as intravenous
immunoglobulin (IVIG), corticosteroids, azathioprine, and/or a thrombopoietin receptor
agonist.

Exclusion Criteria:

1. Subjects who have not been diagnosed with ITP. 2 Subjects who are younger than 3 years
old 3. Subjects who have a medical condition that would be adversely affected by high dose
steroids