Amifostine and rituximab in refractory immune thrombocytopaenia: A case series.

Background And Objectives: Management of refractory immune thrombocytopaenia (ITP) can be challenging. Amifostine, a thiophosphate prodrug, induces megakaryocyte maturation. In 2010, Fan et al. published results for 21 Chinese splenectomized patients, aged 13-92, with steroid-refractory ITP. Nineteen patients (15 patients aged  >18 years) achieved remission 2 months post-amifostine. This is the first publication utilizing amifostine and rituximab in refractory ITP.

Materials And Methods: At the Cairns Hospital in Australia, we identified five patients treated with amifostine and rituximab for refractory ITP. Amifostine IV 400 mg once daily was administered 5 days/week for 5 weeks as tolerated. Rituximab was administered concurrently with/preceding amifostine based on clinician preference. Data were obtained through medical records and follow-up serology up to 5 years post-amifostine was available.

Results: Three cases demonstrated durable responses up to 5 years' follow-up. One patient initially achieved remission but relapsed 1-year post-amifostine. One patient who did not have a splenectomy prior to amifostine did not respond.

Conclusion: Three out of five patients achieved durable responses with amifostine and rituximab. Although there is confounding by rituximab, given its established low durable response rate, it is likely that the excellent long-term responses achieved were a result of amifostine. Clinical trials with larger patient cohorts and further investigation are required to confirm the efficacy and mechanism of amifostine in ITP.