Background: A 37-year-old female with extensively treated refractory immune thrombocytopenia (R-ITP) and platelets of 2 x 109/L, presented for management having exhausted all treatment options. Prior treatments included rituximab, romiplostim, multiple additional medicines, immunoglobulins, and splenectomy. Amifostine's antioxidant and immunomodulatory effects potentially reduce immune-mediated platelet destruction, however efficacy evidence in R-ITP is scarce. A case series of 5 patients with R-ITP used amifostine (400 mg intravenously daily on days 1-5 of a 7-day cycle, for 5 cycles) concurrently with rituximab, achieving responses in four cases (three durable), with the non-responder having not undergone splenectomy. In a similar study, 15 of 17 splenectomised patients responded. Amifostine was sponsor-withdrawn from the Australian Register of Therapeutic Goods in 2024.
Aim: Describe procurement of amifostine and its use with rituximab and romiplostim for an R-ITP case and report platelet response.
Method: Procurement was described descriptively, and platelets and clinical information were derived from retrospective chart review.
Results: Cycle 1 amifostine was administered on days 1-2 and 5-7, due to supply delays. Initial doses were sourced from an interstate hospital, with subsequent stock imported from India. Rituximab was administered weekly during cycles 1 to 4, and weekly romiplostim was recommenced during cycle 3. Within three weeks, platelets remained between 2 and 12 x 109/L. By cycles 4 and 5, platelets increased to 186 and 574 × 10⁹/L, respectively. Over the subsequent five weeks, platelets ranged from 85 to 396 × 10⁹/L before falling to 2 × 10⁹/L during Klebsiella bacteraemia. Following antibiotics, over the next 10 weeks, and to date, platelets recovered and ranged from 24 (drop due to temporary romiplostim dose reduction) to 369 × 10⁹/L.
Conclusion: This case supports the role of amifostine with rituximab and romiplostim in splenectomised patients with R-ITP. Further studies are needed to establish efficacy, optimal dosing, and safety.