This is an open-label, multicenter, Phase Ib/II clinical study designed to evaluate the safety, tolerability, efficacy, pharmacokinetics (PK), and pharmacodynamics (PD) of FL115 in combination with the anti-PD-1 monoclonal antibody, in participants with advanced solid tumors. All enrolled participants will receive FL115 and Sintilimab via intravenous (IV) infusion. Treatment will continue until disease progression (excluding pseudoprogression), unacceptable toxicity, or other protocol-specified criteria for study or treatment discontinuation, whichever occurs first.
The study consists of two parts: a dose-escalation phase (Phase Ib) and a cohort-expansion phase (Phase II). The Phase 2 part will explore the preliminary efficacy and safety of the combination therapy in patients with advanced solid tumors across different tumor types.
Male or female subjects aged 18 years or older and up to 80 years old.
Phase 1b：Patients with specific advanced solid tumors confirmed by histology or cytology who have failed all standard therapies, have no available standard treatment options, or are currently not suitable for standard treatment.
With at least one measurable lesion (according to RECIST v1.1).
ECOG score: 0 - 1.
Previous use of IL-2 or IL-15 agonists, including but not limited to rhIL-15 (NCI), ALT-803 (ALTOR), NKTR-214 (Nektar).
Subjects who received any anti-tumor investigational drugs, approved therapies, biologics, radiotherapy, or immunotherapy within 4 weeks before the first dose (except HRT(Hormoral Replacement Therapy), testosterone, oral contraceptives, ADT for prostate cancer, or endocrine therapy for breast cancer), endocrine therapy within 2 weeks, or palliative local radiotherapy within 14 days.
Within 2 weeks before the first administration of the study drug, received traditional Chinese medicine for anti-tumor indications.
Subjects who received oral fluoropyrimidines or small-molecule targeted therapies discontinued the treatment ≤2 weeks or 5 half-lives (whichever is longer) prior to the first dose of the study drug.