Study to Evaluate Safety and PK of CHS-006 in Combination With Toripalimab in Patients With Advanced Solid Tumors

This phase 1 open-label study will evaluate the safety, tolerability, pharmacokinetics (PK), and preliminary efficacy of CHS-006 in combination with toripalimab in 2 phases. Phase 1 (Dose Optimization phase) will explore 2 different dose combinations in participants with advanced/metastatic solid tumors (except pancreatic) and Phase 2 (Indication-specific Expansion phase) will use one selected dose in specific tumor types (non-small cell lung cancer-non squamous \[NSCLC-NS\] and Hepatocellular carcinoma \[HCC\])

The Dose Optimization phase will enroll participants with advanced/metastatic solid tumors (except pancreatic). Up to 20 participants will be randomized into two dosing arms. Two different primary advanced solid tumors have been selected for investigation of antitumor activity in the Indication-specific Expansion phase. Up to 40 participants will be enrolled into each Indication-specific Expansion phase cohort. All participants in both phases will receive CHS-006 in combination with toripalimab intravenously (IV) every 3 weeks (Q3W).

Eligibility Criteria:
Inclusion Criteria:

* Males and females, ≥18 years old;
* Histopathologically or cytologically confirmed advanced solid tumor (except pancreatic) with disease progression after at least 1 prior line of standard therapy (Dose Optimization phase);
* Tumor-specific criteria (Indication-specific Expansion phase):
* NSCLC-NS (without sensitizing EGFR/ALK/ROS-1/MET mutations) 2nd line plus (2L+): has received and progressed on at least 1 prior chemotherapy regimen. Prior treatment with both anti-PD-1 therapy and platinum-based chemotherapy either concurrently or sequentially are eligible.
* Hepatocellular carcinoma (HCC) 2L+: has received and progressed on at least 1 prior anticancer regimen. Participants with prior treatment with an anti-PD-1 or PD-L1 agent are eligible.
* Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1 and expected survival ≥12 weeks;
* At least 1 measurable lesion per RECIST v1.1;
* Adequate organ and marrow function

Exclusion Criteria:

* Current or prior use of systemic anticancer therapy, including but not limited to chemotherapy, immunotherapy, biologic therapy, hormone therapy, and targeted therapy, within 28 days prior to the 1st dose of CHS-006;
* NSCLC participants with genomic mutations (e.g., EGFR, ALK, ROS-1, MET, etc.) for which FDA-approved targeted therapies are available or require progression on appropriate prior to enrollment;
* Prior exposure to monoclonal antibodies (mAbs) targeting TIGIT or any of its ligands, including CD155, CD112, or CD113;
* Major surgery within 28 days prior to the 1st dose of CHS-006 or still recovering from prior surgery;
* Symptomatic or untreated central nervous system (CNS) metastases;
* Use of therapeutic immunosuppressive medication within 28 days prior to the 1st planned dose of CHS-006;
* Receipt of live, attenuated vaccination within 30 days prior to the 1st dose of CHS- 006;
* History of active autoimmune disease within the past 2 years, with the following exceptions: vitiligo, alopecia, endocrinopathies controlled by hormone replacement therapy, rheumatoid arthritis and other arthropathies that have not required immunosuppression other than nonsteroidal anti-inflammatory agents, celiac disease controlled by diet, or psoriasis controlled with topical medication;
* Participants with another active solid tumor that has not been curatively treated.