During the 65th ASH meeting that took place in San Diego in December 2023, many interesting abstracts concerning immune thrombocytopenia have been presented, covering different topics from the pathogenesis to treatments, from diagnosis to bleeding and thrombotic risk.
Here you can find a summary of the most relevant presentations; for the complete list of the abstracts, please visit the American Society of Hematology official website.
Particular scenarios.
Old and new treatment approaches may have an application in particular settings, such as pregnancy and secondary ITP which are often excluded from clinical trials and label indications. Data about thrombocytopenia secondary to immunotherapy have been presented, and about the use of TPO-mimetics in patients with anti-phospholipid syndrome, that are at an increased thrombotic risk. In fact, it is now well known that ITP is not a mere bleeding disorder, encompassing thrombotic and infectious risks, influenced by both the pathophysiology of the disease and the treatments received.
ITP in pregnancy and secondary ITP
The management of ITP may be challenging both for chronic patients who become pregnant as well as for patients newly diagnosed during pregnancy.
Guillet S et al. compared outcomes between these groups. The rate of new diagnosis was comparable between trimesters. 41.2% experienced a bleeding event, and 76.5% required treatment, more frequently in the “newly diagnosed” group. Neonatal ITP was observed in nearly 20% of newborns. For most women, de novo ITP remained active after delivery. He Y et al. investigated the efficacy and safety of the combination of low-dose rhTPO plus IVIg in 19 corticosteroid-resistant ITP patients during pregnancy, achieving a favorable response rate without safety concerns. Chen Y et al. confirmed the efficacy of adding IVIg to corticosteroid therapy to achieve a rapid platelet count increase during pregnancy.
In patients with secondary ITP, particularly those at increased thrombotic risk, such as patients with antiphospholipid syndrome, the use of TPO-RAs is debatable.
Cindy M et al. reported on the use of TPO-RAs in SLE or antiphospholipid syndrome patients, highlighting thrombotic events as a significant concern, especially in patients with a history of APS and other thrombotic risk factors.
With the widespread adoption of immunotherapy, particularly checkpoint inhibitors known for their autoimmune complications, the issue of ITP secondary to immunotherapy (IO-ITP) has become a non-negligible occurrence in everyday clinical practice.
Grinsztejn E et al. compared patients who developed ITP secondary to immunotherapy (IO-ITP) to patients with primary ITP. They identified 241 individuals who had received a checkpoint inhibitor for solid cancers and subsequently developed ITP, compared with a cohort of 14.171 patients with primary ITP. The IO-ITP group exhibited a higher median age, and a more frequent use of TPO-RAs as second-line treatment, with romiplostim being the most commonly prescribed agent.
ITP: risk of infections, thrombosis and bleeding
Immunosuppressive treatment has remained a milestone in the management of ITP and, except for TPO-mimetics, old and new therapeutic approaches aim to suppress the immune system. Frandsen A et al. showed that, compared to the general population, primary ITP patients are at higher risk of infections, which remains higher for several years after the diagnosis.
Despite being primarily hemorrhagic, ITP carries an increased risk of thrombosis. Rast JS et al. evaluated the occurrence and risk factors for venous and arterial thrombotic events (VTE and ATE) in 160 ITP patients in Vienna. The incidence was 6.8% for ATE and 8.7% for VTE. Patients who developed a thrombotic event were older, with more comorbidities, including APS, and had more frequently undergone splenectomy. Conversely, disease duration and treatment with corticosteroids or TPO-RAs were not associated with an increased thrombotic risk.
Monzon Manzano E et al. shed light on platelet dysfunction in ITP patients, finding that this is more common in the elderly, probably contributing to a higher bleeding risk in this population.
The unpredictable disease course and limited predictive factors for treatment response, coupled with the need for frequent treatment changes and associated side effects, may significantly impact the quality of life for both ITP patients and physicians. Bussel JB et al. underscored this perception of an unmet need for well-tolerated therapies capable of curing ITP, as evidenced by the I-WISh 2.0 survey results.