A Study of ATG-022 in Patients With Advanced/Metastatic Solid Tumors

This is a Phase I, multi-center, open-label, dose-finding study of ATG-022 in patients with advanced solid tumours. The study design includes a Dose Escalation Phase which will enroll subjects with advanced/metastatic solid tumors, and a Dose Expansion Phase which will enroll select advanced/metastatic solid tumors with Claudin 18.2-positive expression at the defined maximum tolerated dose (MTD) and/or recommended Phase II dose (RP2D) to further evaluate the safety, tolerability, and efficacy of ATG-022.

Inclusion criteria

• Provision of signed and dated, written informed consent prior to any study-specific procedures, sampling, and analyses.
• Aged at least 18 years as of the date of consent.
• Histological or cytological confirmation of a solid tumor, and have progressed despite standard therapy(ies), or are intolerant to standard therapy(ies), or not applicable for standard therapy(ies).

• Dose Escalation Phase: all solid tumors.
• Dose Expansion Phase: Claudin 18.2 positive solid tumors.
• Subjects should be willing to receive a biopsy at screening, if no former available tumor tissue samples within 36 months prior to participating in the study are provided.
• At least 1 measurable lesion per Response Evaluation Criteria In Solid Tumors (RECIST) v1.1.
• Estimated life expectancy of a minimum of 12 weeks.
• Eastern Cooperative Oncology Group (ECOG) performance status 0 or 1 .
• Females should be using adequate contraceptive measures until 180 days after the end of treatment, should not be breastfeeding, and must have a negative pregnancy test prior to the start of dosing if of child-bearing potential or must have evidence of nonchild-bearing potential by fulfilling one of the following criteria at screening
• Male subjects should be willing to use effective contraception, ie condoms, for the duration of the study and 180 days after the final dose of study treatment.

Exclusion criteria

• Primary central nervous system disease or central nervous system metastatic disease.
• Prior exposure to a Claudin 18.2 targeting agent.
• Prior therapy with any chemotherapy, immunotherapy, anticancer agents, or investigational products from a previous clinical study within 28 days of the first dose of study treatment or within a period during which the investigational product or systemic anticancer treatment has not been cleared from the body (eg, a period of 5 'half-lives'.
• Prior vaccination within 28 days of the first dose of study therapy.
• Prior any solid organ transplant. Autologous stem cell transplant or CAR-T cell infusion < 6 months prior to the first dose of study treatment.
• Active infection including hepatitis B, and/or hepatitis C.
• Known history of human immunodeficiency virus (HIV) infection.
• Any unresolved toxicities from prior therapy greater than Grade 1 at the time of ICF signature, with the exception of alopecia.
• Pregnant or nursing females.
• History of hypersensitivity or history of allergic reactions attributed to drugs with a similar chemical or biologic structure or class to ATG-022.
• Other primary malignancies developed within 5 years prior to the first dose of the study drug, except locally curable malignancies after radical treatment .
• In the opinion of the investigator, subject's complications, or other conditions (psychological, familial, sociological, or geographical etc.) may affect protocol compliance or may be unsuitable for participation in the study.