Real-world effectiveness of romiplostim N01 with or without TPO-RA for cancer therapy-induced thrombocytopenia in cancer patients

Abstract Background: Cancer therapy-induced thrombocytopenia (CTIT) refers to thrombocytopenia occurring in cancer patients as a result of anti-cancer treatments during disease management. This encompasses chemotherapy-induced thrombocytopenia (CIT), as well as thrombocytopenia caused by radiotherapy, targeted therapy, and immunotherapy. This study aimed to evaluate the efficacy and safety of romiplostim N01, alone or combined with small-molecule thrombopoietin receptor agonists (TPO-RAs), for CTIT treatment. Methods: This single-center prospective observational study (ChiCTR2400094696) requires the recruitment of a total of 75 patients. Eligible patients had malignant tumors, were undergoing anti-tumor therapy (chemotherapy, radiotherapy, immunotherapy, or targeted therapy), and had platelet (PLT) counts <75×10^9/L. The primary endpoint was the proportion achieving romiplostim N01 response within 7 days, defined as meeting any of the following without platelet transfusion: 1) PLT increase ≥50×10^9/L, 2) PLT elevation to ≥2 times baseline, or 3) PLT ≥100×10^9/L. Secondary outcomes included PLT count changes, proportion achieving PLT ≥75×10^9/L within 14 days, time to PLT recovery (≥75×10^9/L and ≥100×10^9/L), and adverse events. Results: Between January 1, 2025, and June 27, 2025, 42 patients were included. Median age was 62 years (range: 31-78). Diagnoses included lung cancer (19.0%, n=8), gynecologic cancer (14.3%, n=6), colorectal, hepatobiliary, pancreatic, and gastroesophageal cancers. Most (69.0%) had Stage III/IV disease. Prior anti-tumor therapies included immunotherapy (47.6%, n=20), targeted therapy (26.2%, n=11), and radiotherapy (7.1%, n=3). Romiplostim N01 was combined with other TPO-RAs in 4 patients (9.5%). All patients had ECOG performance status 0-1. The overall response rate (within 7 days) to romiplostim N01 was 61.9% (26/42). Response rates by baseline PLT were: 58.6% (17/29) for PLT 50-75×10^9/L; 70.0% (7/10) for PLT 25-50×10^9/L; 66.7% (2/3) for PLT <25×10^9/L. The median time to achieve PLT ≥100×10^9/L or an increase ≥50×10^9/L from baseline was 6 days (range: 2-7). Only 3 patients (7.1%) required chemotherapy dose reduction/delay due to recurrent CIT. Conclusion: These real-world results suggest romiplostim N01, with or without TPO-RA, is an effective treatment for CTIT, demonstrating high response rates and rapid platelet recovery in a mixed cancer patient population.