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H. Al-Samkari et al.
Figure 1. Chemotherapy-induced thrombocytopenia (CIT) romiplostim treatment pathways. In the weekly romiplostim dosing pathway, romiplostim is administered weekly irrespective of treatment schedule. In the intracycle romiplostim dosing pathway, romiplostim is dosed on chemotherapy off-weeks, except for chemotherapy regimens employing regular treatment without off-weeks in which case romiplostim is administered every other week. Platelet counts are obtained weekly in both pathways.
patients (45%) achieved platelet count ≥100x109/L on romiplostim therapy, with a median time to platelet count ≥100x109/L of 17 days (IQR 8-24 days). This poor rate of response was observed despite substantial romiplostim dose-escalation in these patients (median romiplostim dose, 8 mg/kg [IQR, 5-10 mg/kg]).
Clinical effectiveness and safety outcomes in solid tumor patients
In the 150 solid tumor patients able to continue chemotherapy with romiplostim treatment, number of events and event rates over the 57.7 patient-years at risk were as follows: chemotherapy intensity reduction, 89 events resulting in a rate of 154 events per 100 patient- years at risk; bleeding, 13 events resulting in a rate of 23 events per 100 patient-years at risk; VTE, eight events resulting in a rate of 14 events per 100 patient-years at risk; and platelet transfusion, 62 events resulting in a rate of 107 events per 100 patient-years at risk. Excluding patients with predictors of romiplostim non-response
(50.0 patient-years at risk), number and rates of these out- comes declined as follows: chemotherapy intensity reduc- tion, 65 events, rate 130 per 100 patient-years at risk; bleeding, eight events, rate 16 per 100 patient-years at risk; VTE, seven events, rate 14 per 100 patient-years at risk; and platelet transfusion, 13 events, rate 26 events per 100 patient-years at risk. Of all solid tumor patients 118 out of 150 (79%) had no chemotherapy intensity reductions and 133 out of 150 (89%) required no platelet transfusions while on romiplostim. There were no arterial throm- boembolic events. Tables 2 and 3, respectively, describe the individual VTE and bleeding events in the patient cohort. No patient died of bleeding or thrombosis. The three patients given romiplostim but not able to resume chemotherapy did not experience bleeding or thrombotic events on romiplostim.
Comparison of weekly romiplostim dosing versus intracycle romiplostim dosing in solid tumor patients
Of the solid tumor patients, 80 were treated on the
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haematologica | 2021; 106(4)