P134 | BEYOND SUPPORTIVE CARE: THROMBOPOIETIN RECEPTOR AGONISTS AS THERAPEUTIC ENABLERS IN SOLID TUMORS WITH THROMBOCYTOPENIA. A SINGLE-CENTER EXPERIENCE

Introduction: Thrombocytopenia is a frequent hematologic complication in patients with solid tumors, arising from bone marrow infiltration, immune-mediated destruction, or treatment-related toxicity. Chemotherapeutic agents—especially platinum compounds, taxanes, and antiangiogenic drugs—are commonly implicated. Targeted therapies and immune checkpoint inhibitors have also been associated with immune thrombocytopenia. This condition may limit treatment intensity, increase bleeding risk, and negatively impact prognosis. Thrombopoietin receptor agonists (TPO-RAs) represent a valuable option to restore platelet counts and support the continuation of oncologic therapy in selected patients. Patients and Methods: We retrospectively analyzed 13 patients with solid tumors and thrombocytopenia, either at diagnosis or during anticancer therapy. Data were collected from 2017 to 2024. Median age was 76 years; the cohort included 6 females and 7 males. Bone marrow biopsy was performed in 12 cases, including cytogenetic and molecular analyses. Three patients harbored TP53 mutations, and one showed myelophthisis. Tumor types included breast, ovarian, prostate, bladder, lung, pancreatic and neuroendocrine carcinoma, renal cancer, and Hodgkin lymphoma. Clinical data included tumor histology, hematologic parameters, treatments, and responses to supportive therapy. Results: Four patients initially received corticosteroids or intravenous immunoglobulins, with limited or partial responses. Subsequently, 11 patients were treated with eltrombopag, 6 with romiplostim, and 1 with avatrombopag. Four patients required a switch to a second TPO-RA, and one a third as well. All achieved complete platelet responses, enabling continuation of oncologic therapy. TPO-RA dosing was individualized based on each patient’s treatment phase and platelet trend, with weekly complete blood counts submitted remotely by patients or referring oncologists. At the time of analysis, 10 patients were alive. Three patients died, including the one with myelophthisis, who continued breast cancer treatment for three years before death. (Tab. 1) Conclusion: Our experience supports the use of TPO-RAs in thrombocytopenic patients with solid tumors. These agents may enable full oncologic treatment delivery and improve clinical outcomes. In selected patients, restoring platelet counts is not just supportive care—it is a therapeutic bridge to maintaining oncologic intent and potentially prolonging survival.