A Prospective, Randomized, Open-Label, Controlled Study of Romiplostim N01 Combined With All-Trans Retinoic Acid Versus Romiplostim N01 Alone for Persistent Isolated Chemotherapy-Induced Thrombocytopenia in Patients With Complete Remission of Gynecologic, Breast, or Lung Solid Tumors
This is a prospective, randomized, open-label, active-controlled study to evaluate the efficacy and safety of Romiplostim N01 plus all-trans retinoic acid (ATRA) compared with Romiplostim N01 alone in adults with persistent isolated chemotherapy-induced thrombocytopenia (PICIT) after complete remission of selected gynecologic, breast, or lung solid tumors, including but not limited to non-small cell lung cancer (NSCLC), ovarian cancer, and breast cancer. Eligible participants will be randomized in a 1:1 ratio to receive Romiplostim N01 plus oral ATRA or Romiplostim N01 alone for 12 weeks, with follow-up through Week 24. The primary outcome is the overall platelet response rate at Week 12, defined as platelet count \>50 x 10\^9/L in at least 2 of the last 3 scheduled platelet assessments up to Week 12. Secondary outcomes include sustained response during Weeks 13 to 24, complete and partial response rates, duration of response, time to response, platelet count changes, platelet transfusion requirements, bleeding events, and safety.
• Age 18 years or older.
• Prior diagnosis of a selected gynecologic, breast, or lung solid tumor, including but not limited to non-small cell lung cancer (NSCLC), ovarian cancer, or breast cancer. Other eligible tumor types may include endometrial cancer, cervical cancer, fallopian tube cancer, primary peritoneal cancer, and other lung cancers, if clinically appropriate and if all other eligibility criteria are met.
• Complete remission of the underlying tumor after chemotherapy or antitumor treatment, with tumor-related treatment discontinued for at least 12 weeks before enrollment, no evidence of recurrence or progression by specialist assessment, and no current need for additional tumor-directed therapy.
• Persistent isolated chemotherapy-induced thrombocytopenia, defined as platelet count \<30 x 10\^9/L on two peripheral blood tests at least 7 days apart; or platelet count slightly higher than 30 x 10\^9/L with dependence on platelet transfusion to maintain a safe platelet level.
• Thrombocytopenia has persisted since the last chemotherapy treatment without a clear trend of spontaneous recovery.
• Red blood cell count and neutrophil count are generally preserved, without clinically significant anemia or neutropenia.
• Bone marrow assessment performed within 1 year after tumor diagnosis and chemotherapy shows no tumor cell infiltration; megakaryocyte count is normal or increased, with or without maturation impairment.
• No hepatosplenomegaly, portal hypertension, or other evidence suggesting abnormal platelet redistribution as the main cause of thrombocytopenia.
• Prior treatment with at least one thrombopoietin receptor agonist or recombinant human thrombopoietin for PICIT without response, defined as failure of platelet count to rise to a safe level or to at least 2 times baseline after at least 2 weeks of standard-dose treatment.
⁃ No prior use of Romiplostim N01.
⁃ Other platelet-raising medications have been discontinued before enrollment. No washout period is required for prior thrombopoietin receptor agonists; other investigational drugs or off-label treatments must be discontinued for at least 1 month before enrollment.
⁃ Ability to understand and sign the informed consent form and willingness to comply with study visits and procedures.
⁃ Participants of reproductive potential must agree to use effective contraception during study treatment. Female participants of childbearing potential must have a negative pregnancy test before enrollment.