Immune (Idiopathic) Thrombocytopenic Purpura (ITP): Treatment Pattern and Splenectomy Rate from a Multinational Prospective Observational Study

ITP is an autoimmune disease characterized by low platelet counts due to increased platelet destruction and inadequate platelet production. It is often a chronic disorder that requires long-term treatment. Current common treatment therapies for chronic ITP include corticosteroids, intravenous immunoglobulins (IVIG), rituximab, and anti-D antibody. Splenectomy may be required for those patients who do not respond or relapse after these medical therapies, or require intolerable doses to achieve safe platelet counts. Few studies have reported treatment pattern of current therapies for ITP. We report results of an international multi-center retrospective and prospective observational study of adult patients receiving treatments and/or splenectomy for chronic ITP. Patients with a diagnosis of ITP were enrolled from 100 community and academic centers. Date of 1st ITP diagnosis, treatments received and medical history were obtained retrospectively from patient chart data. ITP treatments, dose, response, and duration of response were collected prospectively for 12 months. Among 326 patients with ITP studied (mean age=54 years, male 40.2%), 24% received a splenectomy during this study. In patients who were not splenectomized (n=248), 77% received ITP medications with corticosteroids being the most frequently prescribed medication among patients who received 1 type of ITP treatment. IVIG was most frequently prescribed in patients who received 2 types of ITP treatments, and patients were most likely to receive a splenectomy after receiving 2 or more types of ITP treatments (table). In splenectomized patients, the average duration from ITP diagnosis to splenectomy was 2.79 years (n=74, SD=4.42, min=0, max=23.38). Prior to surgery, splenectomized patients were most likely to receive corticosteroids in patients receiving 1 type of treatment, and IVIG in patients receiving 2 types of ITP treatments. Following surgery, splenectomized patients were also most likely to receive corticosteroids in patients receiving 1 type of ITP medication, and rituximab in patients with 2 types of ITP medications. Overall, patients with ITP are exposed to numerous ITP treatments, among which, corticosteroids were most frequently used in both splenectomized and non-splenectomized patients. All patients receiving a splenectomy also required 1 or more ITP treatments following surgery. These results demonstrate that current ITP therapies are limited in efficacy and durability and often lead to patients receiving multiple types of ITP treatments. Novel ITP therapies with better efficacy and durable response are needed. | | | | Splenectomizedb(N=78) | | |:---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ----------------------- | --------------------- | ---------------------- | ----------------------- | -------------------------- | | | ITP Treatments Received | Overall (N=326) | Pre-Splenectomy (N=74) | Post-Splenectomy (N=74) | Non-Splenectomized (N=248) | | aMost frequently used treatment or therapy observed within that subgroup (receiving 1, 2, 3, 4 or more treatments). Percentages (%) are calculated as n divided by the total number of patients within the corresponding subgroup. | | b4 splenectomized patients were excluded from the analysis due to missing data. | | | | 58 (18) | | | 58 (23) | | | 1 | 89 (27) | 23 (31) | 37 (50) | 83 (33) | | Exposure Rate n(%) | 2 | 82 (25) | 15 (20) | 17 (23) | 62 (25) | | | 3 | 49 (15) | 18 (24) | 11 (15) | 27 (11) | | | 4 or More | 48 (15) | 18 (24) | 9 (12) | 18 (7) | | | 1 | Corticosteroids (71%) | Corticosteroids (57%) | Corticosteroids (22%) | Corticosteroids (76%) | | Most Frequently Used Therapy (%)a | 2 | IVIG (39%) | IVIG (73%) | Rituximab (24%) | IVIG (52%) | | | 3 | Splenectomy (45%) | IVIG (56%) | IVIG (27%) | IVIG (52%) | | | 4 or More | Splenectomy (63%) | Rituximab (11%) | Vincristine (22%) | Rituximab (78%) |