Contributions
Abstract: EP1126
Type: E-Poster Presentation
Session title: Platelet disorders
Background
Romiplostim is approved for the treatment of chronic immune thrombocytopenia (ITP for ≥12 months) in adults who are refractory to other treatments such as steroids and intravenous immunoglobulin. In 2021, the romiplostim indication was expanded to also cover adult patients with ITP for <12 months duration.
Aims
To examine baseline characteristics, dosage, and platelet endpoints after initiation of romiplostim in newly diagnosed (ITP duration <3 months), persistent (ITP duration 3-12 months) and chronic (ITP duration >12 months) ITP patients treated in routine clinical practice in Denmark, Sweden and Norway.
Methods
From the population-based Nordic Country Patient Registry for Romiplostim, we included all adult (≥18 years) romiplostim-exposed patients with ITP for at least 6 months between 1 April 2009 and 31 December 2018. We disaggregated the cohort according to time from ITP diagnosis to romiplostim initiation into newly diagnosed, persistent, and chronic ITP. For each exposure group, we described patient characteristics at romiplostim initiation, romiplostim dosage, duration of romiplostim treatment, platelet count during and after romiplostim treatment, and durable platelet response (defined as ≥75% of all recorded platelet count measurements ≥50 x 109/L during weeks 14 through 24 after date of first romiplostim administration).
Results
Among the 262 patients initiating romiplostim, 77 had newly diagnosed, 41 had persistent, and 144 had chronic ITP. The proportions aged 70+ years were 26%, 42% and 29% in the three groups, and 13%, 15%, and 16% had Charlson Comorbidity Index Score ≥3, respectively.
The three groups had similar proportions of patients with a platelet count <50x109/L within 90 days before romiplostim initiation (91%, 88%, and 90%, respectively). The proportions of patients with <2 recorded ITP medication within 6 months prior to romiplostim were 33%, 37%, and 43% in the three groups, respectively. The median of first romiplostim doses were also similar (1.1, 1.1, 1.1 µg/kg, respectively), while there were slight differences in last maintenance romiplostim doses (3.6, 2.5, 2.9 µg/kg, respectively). The median [quartile (Q) Q1,Q3] duration of romiplostim exposure was 19 [3,59], 17 [7,59], and 35 [8,125] weeks, respectively.
The median [Q1, Q3] time to first recorded platelet count ≥50x109/L within 2 to 24 weeks after romiplostim initiation was 24 [19,34] days for newly diagnosed ITP and 21 [19,34] days for persistent or chronic ITP. The median [Q1,Q3] platelet count (x109/L) during romiplostim treatment was 71 [23,154] in newly diagnosed, 75 [41,133] in persistent, and 76 [33,153] in chronic ITP. The median [Q1, Q3] of the last platelet count within 31-100 days after discontinuing romiplostim among 47, 16, and 51 in patients not receiving any ITP treatment in the period was 171 [107,297], 120 [59,259], and 120 [47,249), respectively. Durable platelet response was achieved in 66%, 53%, and 54% of patients with newly diagnosed, persistent, and chronic ITP, respectively.
Conclusion
Baseline characteristics and platelet-based outcomes were comparable among newly diagnosed, persistent, and chronic ITP groups treated with romiplostim in routine clinical care of patients with at least six months history of ITP. This suggests that initiation of romiplostim is not guided by ITP duration but rather by patient and disease characteristics.
Keyword(s): Immune thrombocytopenia (ITP), Thrombocytopenia, Thrombopoietin (TPO)
Abstract: EP1126
Type: E-Poster Presentation
Session title: Platelet disorders
Background
Romiplostim is approved for the treatment of chronic immune thrombocytopenia (ITP for ≥12 months) in adults who are refractory to other treatments such as steroids and intravenous immunoglobulin. In 2021, the romiplostim indication was expanded to also cover adult patients with ITP for <12 months duration.
Aims
To examine baseline characteristics, dosage, and platelet endpoints after initiation of romiplostim in newly diagnosed (ITP duration <3 months), persistent (ITP duration 3-12 months) and chronic (ITP duration >12 months) ITP patients treated in routine clinical practice in Denmark, Sweden and Norway.
Methods
From the population-based Nordic Country Patient Registry for Romiplostim, we included all adult (≥18 years) romiplostim-exposed patients with ITP for at least 6 months between 1 April 2009 and 31 December 2018. We disaggregated the cohort according to time from ITP diagnosis to romiplostim initiation into newly diagnosed, persistent, and chronic ITP. For each exposure group, we described patient characteristics at romiplostim initiation, romiplostim dosage, duration of romiplostim treatment, platelet count during and after romiplostim treatment, and durable platelet response (defined as ≥75% of all recorded platelet count measurements ≥50 x 109/L during weeks 14 through 24 after date of first romiplostim administration).
Results
Among the 262 patients initiating romiplostim, 77 had newly diagnosed, 41 had persistent, and 144 had chronic ITP. The proportions aged 70+ years were 26%, 42% and 29% in the three groups, and 13%, 15%, and 16% had Charlson Comorbidity Index Score ≥3, respectively.
The three groups had similar proportions of patients with a platelet count <50x109/L within 90 days before romiplostim initiation (91%, 88%, and 90%, respectively). The proportions of patients with <2 recorded ITP medication within 6 months prior to romiplostim were 33%, 37%, and 43% in the three groups, respectively. The median of first romiplostim doses were also similar (1.1, 1.1, 1.1 µg/kg, respectively), while there were slight differences in last maintenance romiplostim doses (3.6, 2.5, 2.9 µg/kg, respectively). The median [quartile (Q) Q1,Q3] duration of romiplostim exposure was 19 [3,59], 17 [7,59], and 35 [8,125] weeks, respectively.
The median [Q1, Q3] time to first recorded platelet count ≥50x109/L within 2 to 24 weeks after romiplostim initiation was 24 [19,34] days for newly diagnosed ITP and 21 [19,34] days for persistent or chronic ITP. The median [Q1,Q3] platelet count (x109/L) during romiplostim treatment was 71 [23,154] in newly diagnosed, 75 [41,133] in persistent, and 76 [33,153] in chronic ITP. The median [Q1, Q3] of the last platelet count within 31-100 days after discontinuing romiplostim among 47, 16, and 51 in patients not receiving any ITP treatment in the period was 171 [107,297], 120 [59,259], and 120 [47,249), respectively. Durable platelet response was achieved in 66%, 53%, and 54% of patients with newly diagnosed, persistent, and chronic ITP, respectively.
Conclusion
Baseline characteristics and platelet-based outcomes were comparable among newly diagnosed, persistent, and chronic ITP groups treated with romiplostim in routine clinical care of patients with at least six months history of ITP. This suggests that initiation of romiplostim is not guided by ITP duration but rather by patient and disease characteristics.
Keyword(s): Immune thrombocytopenia (ITP), Thrombocytopenia, Thrombopoietin (TPO)