This is a study on the safety and efficacy of malic acid supplementation combined with immunotherapy for anti-tumor treatment in patients with solid tumors. The primary study objective is to determine the oral safety of malic acid; Secondary study objectives: 1. To evaluate the preliminary efficacy of malic acid in the study population. 2. To determine the recommended phase 2 dose (RP2D) of oral malic acid. Exploratory endpoints: Immune indicators including white blood cell count, neutrophil, lymphocyte, monocyte, eosinophil and basophil (count/proportion); metabolic indicators including blood glucose, triglycerides; nutritional indicators including body weight.
Aged ≥ 18 years (inclusive), male or female;
Patients with malignant solid tumors such as colorectal cancer, lung cancer, and melanoma, confirmed by histopathological or cytological examination;
Patients have at least one measurable lesion;
Undergoing systematic anti-tumor treatment with immunotherapy;
Subjects who have not recovered from adverse events caused by any intervention to ≤ Grade 1 (except for alopecia, hearing impairment, and Grade ≤ 2 neurological or endocrine disorders requiring replacement therapy) prior to the first dose;
Subjects who have undergone major or moderate surgery (other than for diagnosis or biopsy) within 28 days prior to the first dose, or are expected to undergo major surgery during the study;
Subjects with severe chronic obstructive pulmonary disease (COPD) (Global Initiative for Chronic Obstructive Lung Disease [GOLD] ≥ Grade 3), or who have had intestinal adhesions or intestinal obstruction within 6 months prior to the first dose;
Subjects with severe cardiovascular diseases, such as New York Heart Association (NYHA) Heart Disease (Class III or higher), myocardial infarction within 6 months, current unstable angina, or uncontrolled hypertension (systolic blood pressure > 150 mmHg and/or diastolic blood pressure > 100 mmHg);