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The emergence of rituximab biosimilars offers the prospect of significant savings to the healthcare system. However, these drugs have never been evaluated for treating immune thrombocytopenia (ITP). This was an observational, matched study. We included adults who received a rituximab biosimilar for ITP. Each rituximab-naïve biosimilar patient was matched with two controls from the historic ITP-ritux registry. For non-naïve patients, we compared the response to the biosimilar with that observed with the reference product. Response status was defined according to international criteria. We included 107 patients; 55 receiving Rixathon™ and 52 Truxima™. Three months after the first infusion of rituximab biosimilars, the overall response rate was 47/74 (63.5%) versus 76/142 (53.5%) for the matched controls receiving the reference product (p =.13). The 3-month overall response rate was 76.5% for Rixathon™ versus 51.5% for the matched control group (p =.01) and 21/40 (52.5%) for Truxima™ versus 41/74 (55.4%) for the matched controls (p =.81). For non-naïve patients, the response pattern was similar to that observed previously with the reference product. Safety was analogous to that observed with the reference product. Rituximab biosimilars seemed safe and effective for ITP treatment. What is the context? Immune thrombocytopenia (ITP) is an autoimmune disease defined by a low platelet count without any other cause of thrombocytopenia. Patients with ITP may experience severe bleedings. Rituximab, a biotechnological therapy, is a valid second-line treatment option for ITP. Biotechnological therapies are expensive. Because the patent expiratory date of the reference product of Rituximab expired, highly similar drugs called biosimilars have been developed and used in ITP treatment without any direct evaluation in this particular disease. What is new? In this study, we evaluate the efficacy and safety of rituximab biosimilars versus the reference product for treating adult ITP We included adults who received a rituximab biosimilar for ITP. Each rituximab-naïve biosimilar patient was matched with two controls from a historic registry that included ITP patients treated by the reference product. For non-naïve patients, we compared the response to the biosimilar with that observed with the reference product. For naïve and non-naïve patients, the response pattern was similar to that observed previously with the reference product. Safety was analogous to that observed with the reference product. What is the impact? This study provides further evidence that rituximab biosimilars are safe and effective for immune thrombocytopenia treatment. [ABSTRACT FROM AUTHOR]

In anecdotal reports, some patients with immune thrombocytopenia ( ITP) maintained platelet counts after discontinuing romiplostim. Here, we examined rates of platelet response (≥50 × 109/l), remission , splenectomy and adverse events in patients with primary ITP duration ≤6 months who were treated with romiplostim for ≤12 months. The starting dose of romiplostim was 1 μg/kg; concomitant and rescue treatments were permitted to maintain platelet counts. Patients with platelet counts ≥50 × 109/l at the end of 12 months entered a dose taper in which the romiplostim dose was decreased as long as platelet counts were maintained. Remission (platelet count ≥50 × 109/l for 24 consecutive weeks with no ITP treatments) was evaluated in patients once romiplostim was discontinued. Over the 12 months, a high response rate (>90%) was observed. Platelet response occurred quickly (median, ~2 weeks) and was observed for a cumulative median of 11 months. Remission was observed in 24 patients (32%); there were no significantly predictors of remission. Most (20/24) patients had remission start before the forced taper. No new safety signals were identified. Thus, in patients with early-stage ITP, romiplostim was well tolerated and induced rapid responses, with remission occurring in approximately one-third of patients ( NCT01143038, Amgen 20080435). [ABSTRACT FROM AUTHOR]

Romiplostim was effective, safe, and well-tolerated over 6-12 months of continuous treatment in Phase 3 trials in patients with immune thrombocytopenia ( ITP). This report describes up to 5 years of weekly treatment with romiplostim in 292 adult ITP patients in a long-term, single-arm, open-label study. Outcome measures included adverse events (including bleeding, thrombosis, malignancy, and reticulin/fibrosis), platelet response (platelet count >50 × 109 per litre), and the proportion of patients requiring rescue treatments. Treatment-related serious adverse events were infrequent and did not increase with longer treatment. No new classes of adverse events emerged. Thrombotic events occurred in 6·5% of patients and were not associated with platelet count. Median platelet counts of 50-200 × 109 per litre were maintained with stable doses of romiplostim (mean 5-8 μg/kg; generally self-administered at home) throughout the study. A platelet response was achieved at least once by 95% of patients, with a platelet response maintained by all patients on a median 92% of study visits. There was a low rate of bleeding and infrequent need for rescue treatments. In conclusion, this study demonstrated that romiplostim was safe and well-tolerated over 614 patient-years of exposure in ITP patients, and that efficacy was maintained with stable dosing for up to 5 years of continuous treatment. [ABSTRACT FROM AUTHOR]