This is a single-arm, open, II phase study to evaluate the safety and efficacy of Toripalimab, pemetrexed and carboplatin in the treatment of locally advanced malignant MPM in 15 newly diagnosed patients with locally advanced malignant MPM.

Inclusion Criteria:

• Sign informed consent;
• Age ≥ 18 years;
• Histology or cytology confirmed upper or mixed type of MPM, and previously untreated;
• Imaging confirmed that MPM was locally advanced;
• PET-CT confirmed no metastasis;
• ECOG physical status score 0-1;
• Life expectancy at least 12 weeks.
• Have measurable lesions
• Good function of other major organs (liver, kidney, blood system, etc.):-absolute neutrophil count ((ANC) ≥ 1.5 × 109), platelet (≥ 100 × 109), hemoglobin (≥ 90g/L). Note: patients shall not receive blood transfusion or growth factor support within 14 days before blood collection during the screening period;-International standardized ratio (INR) or prothrombin time (PT) ≤ 1.5 × normal upper limit (ULN);-activated partial thromboplastin time (APTT) ≤ 1.5 × ULN;- serum total bilirubin ≤ 1.5 × ULN (Gilbert syndrome patients with total bilirubin must be < 3×ULN). Fertile female patients with aspartate and alanine aminotransferase (AST and ALT) ≤ 2.5 × ULN, or liver metastasis with AST and ALT ≤ 5 × ULN
• Fertile female patients must voluntarily take effective contraceptive measures more than 120 days after chemotherapy or the last administration of triplizumab, whichever is later, and the urine or serum pregnancy test results less than 7 days before entering the group were negative.
• Unsterilized male patients must voluntarily take effective contraceptive measures ≥ 120 days after chemotherapy or the last administration of triplizumab, whichever is the later.

Exclusion Criteria:

• Any systemic anticancer therapy for MPM, including surgery, local radiotherapy, cytotoxic drug therapy, targeted drug therapy and experimental therapy;
• Any Chinese herbal medicine used to control cancer was used within 14 days before the first administration of the study drug;
• Patients with malignant tumors other than MPM in the five years before the start of this trial.
• Complicated with unstable systemic diseases such as uncontrolled hypertension, severe arrhythmias, etc.;
• Active, known or suspected autoimmune diseases, or autoimmune paraneoplastic syndrome requiring systemic treatment;
• Allergic to experimental drugs;
• Previous or current interstitial lung disease;
• Complicated with HIV infection or active hepatitis.
• Those who were injected with vaccines or antibiotics within 4 weeks before the start of this trial, or who had undergone other major operations or severe injuries within the previous 2 months;
• Clinically uncontrolled pleural effusion or ascites requiring pleural or abdominal puncture drainage within 2 weeks before admission;
• Pregnant or lactating women;
• Any malabsorption;
• Those with neurological diseases or mental disorders.
• Participated in another therapeutic clinical study at the same time;
• Other researchers did not consider it appropriate to enroll in the group.