An Phase I/IIa Clinical Study to Evaluate the Safety/Tolerability, Pharmacokinetics and Preliminary Efficacy of INB301 Injection in Patients With Cancer Cachexia

Inclusion Criteria: * Subjects who voluntarily participate in the study and voluntarily sign the informed consent form; * Male or female ≥ 18 years of age; * Subjects with histologically or cytologically confirmed malignant solid tumors (including pathologically confirmed non-small cell lung cancer, colorectal cancer, pancreatic cancer, esophageal cancer or breast cancer, etc.) who are receiving or have completed anti-cancer treatment and have no significant cancer progression 28 days before the first dose, and in the investigator's expectation are unlikely to change the anti-cancer regimen due to disease progression or do not require any anti-cancer treatment within the first cycle (21 days) of the study; * Definitely diagnosed as cancer cachexia according to the 2025 Definition and Classification of Cancer Cachexia: An International Consensus" combined with clinical practice: one of the following occurs within 6 months (recognized documentation is required for past weight data): involuntary weight loss \> 5%, or weight loss \> 2% when BMI \< 18.5 kg/m² ; * Serum GDF-15 level ≥ 1200 pg/mL within 28 days prior to the first dose (only applicable to Phase I dose expansion and Phase IIa); * Adequate organ function, i.e., meeting laboratory criteria: * Hematology: absolute neutrophil count ≥ 1.0×10⁹/L, platelets ≥ 75×10⁹/L, hemoglobin ≥ 80 g/L; * Renal: serum creatinine ≤ 1.5 × ULN (if serum creatinine \> 1.5 × ULN, creatinine clearance calculated with Cockcroft formula ≥ 3…