QLF-3108

Phase 1a: Dose escalation and PK expansion Main study objectives: To evaluate the safety and tolerability of single and multiple administrations of QLF3108 for injection in patients with advanced solid tumors, and to determine the recommended dose for Phase 2 (RP2D). Secondary study objectives: To evaluate the pharmacokinetic (PK) characteristics, immunogenicity, and preliminary efficacy of QLF3108 for injection after single and multiple administrations. Phase 1b: Single-drug efficacy expansion Main study objectives: To evaluate the preliminary efficacy of QLF3108 for injection as a monotherapy in patients with advanced solid tumors. Secondary study objectives: To evaluate the safety, PK characteristics, and immunogenicity of QLF3108 for injection as a monotherapy in patients with advanced solid tumors.