The population receiving immunotherapy is heterogeneous. Multiple factors, including combination treatment modalities, influence the immune response, and survival outcomes also vary among individuals receiving immunotherapy. The aim of this study is to develop and validate a clinical prediction model that can predict survival outcomes of immunotherapy for malignant tumors, and to assess the calibration and discrimination of this model in a prospective independent cohort.

Inclusion Criteria:

1. Age ≥ 18 years;
2. Histologically or cytologically confirmed malignant tumor;
3. Planned to receive immune checkpoint inhibitor (e.g., PD-1/PD-L1 inhibitor)-based therapy (monotherapy or in combination with chemotherapy/targeted therapy/radiotherapy, etc.);
4. At least one measurable lesion according to the Response Evaluation Criteria in Solid Tumors (RECIST 1.1);
5. Adequate organ function (with reference to laboratory tests such as complete blood count, liver and kidney function tests);
6. Voluntary participation in this study, signed informed consent, and willingness to comply with follow-up.

Exclusion Criteria:

1. Active autoimmune disease requiring systemic immunosuppressive therapy (physiological doses of glucocorticoid replacement therapy or inhaled steroids are permitted);
2. Active, uncontrolled severe infection, or known human immunodeficiency virus (HIV) infection;
3. Pregnant or breastfeeding women;
4. Any unstable systemic disease (including but not limited to severe cardiac, hepatic, or renal insufficiency).

Patients aged ≥18 years with histologically or cytologically confirmed malignant tumors and who are planned to receive immune checkpoint inhibitor-based therapy.