A prospective, single-arm, exploratory study on the efficacy and safety of romiplostim N01 for cancer treatment–induced thrombocytopenia in patients with gastrointestinal cancers.

e16346 Background: Cancer Treatment-Induced Thrombocytopenia (CTIT) is a common complication in patients with gastrointestinal (GI) cancers, often leading to treatment delays, dose reductions, and increased bleeding risk. Romiplostim N01 is recommended for CTIT but lacking specifically evidence in GI cancer. This study aims to explore the efficacy and safety of Romiplostim N01 in GI cancer patients with CTIT. Methods: This prospective, single-arm, multi-center study conducted from July 2025 to June 2027. 100 adult patients with GI cancers and developed CTIT (platelet count < 50×10⁹/L) following anticancer therapy will be enrolled. Patients received subcutaneous Romiplostim N01 (starting dose 3 µg/kg/week) for up to 8 weeks. The primary endpoint was the proportion achieving platelet count ≥50×10⁹/L at week 2 after treatment initiation. Secondary endpoints included the proportion of patients achieving a platelet response (increase ≥ 50×10⁹/L without transfusion) within 7 days, time to platelet recovery (≥50×10⁹/L, ≥100×10⁹/L), transfusion requirements, and safety. Results: As of January 20, 2026, a total of 21 subjects were enrolled (14 males, 7 females) with a median age of 67 years (range, 53-76). Primary tumor types included rectal cancer (23.8%, 5/21), colon cancer (19.0%, 4/21), cholangiocarcinoma (19.0%, 4/21), with the remaining being gastric cancer (3/21) and others. Most patients (20/21) had an ECOG status of 0-2. Thirteen patients had previously received immunotherapy, while the others underwent standard chemotherapy. Eighteen subjects received one dose of Romiplostim N01 (3 µg/kg/week), and three received two doses. The median baseline platelet count was 37×10⁹/L (range, 32-42×10⁹/L). Nineteen subjects (90.5%, 19/21) achieved the primary endpoint (platelet count ≥50×10⁹/L) within two weeks, and the median platelet count after response was 76×10⁹/L (range, 55-137×10⁹/L). The median time to platelet recovery ≥50×10⁹/L was 7 days (95% CI, 2.734-11.266), and the median time to platelet recovery ≥100×10⁹/L was 13.5 days (95% CI, 7.5-29.5). No patient required additional platelet transfusions. Adverse events were mild to moderate, primarily arthralgia and headache, and all resolved. No treatment-related serious adverse events (SAEs) were reported. Conclusions: Romiplostim N01 shows promising efficacy for CTIT in GI cancers, with most patients achieving rapid platelet recovery (median 7 days) and no need for transfusions. The manageable safety profile suggests it is a viable supportive care option. These findings will provide further support for its clinical use. Clinical trial information: ChiCTR2500106841.