Safety and Preliminary Antitumor Activity of Ivonescimab Plus Pemetrexed and Platinum-Based Chemotherapy in Advanced Malignant Pleural Mesothelioma

This Phase 1a, open-label, dose-escalation study evaluates the safety, tolerability, and preliminary antitumor activity of ivonescimab in combination with pemetrexed and platinum-based chemotherapy as first-line treatment for advanced malignant pleural mesothelioma. Ivonescimab is evaluated at sequential dose levels of 3, 10, and 20 mg/kg using a 3+3 dose-escalation design.

Inclusion Criteria: 1. Age 18 to 75 years. 2. Histologically confirmed advanced or metastatic malignant pleural mesothelioma not amenable to surgery. 3. No prior systemic anticancer therapy for advanced disease. 4. ECOG PS 0-1. 5. At least one measurable lesion according to modified RECIST (mRECIST). 6. Adequate organ function for study treatment. 7. Patients with asymptomatic or stable brain metastases are eligible. 8. Able to understand the study, provide written informed consent, and comply with study procedures. Exclusion Criteria: 1. Active autoimmune disease requiring systemic treatment or other contraindications to immunotherapy. 2. Uncontrolled hypertension, significant bleeding risk, or other contraindications to antiangiogenic therapy. 3. Active interstitial lung disease or noninfectious pneumonitis. 4. Active infection requiring systemic treatment. 5. Other active malignancies requiring anticancer treatment. 6. Severe uncontrolled medical conditions that may interfere with study treatment. 7. Pregnant or breastfeeding women.