Evaluation of Safety and Tolerability of ATB-320 in Participants With Progressive or Metastatic Solid Tumors

• Primary objective: to evaluate the maximum tolerable dose (MTD), recommended phase 2 dose (RP2D), and dose limiting toxicities (DLTs) of ATB-320 in patients with progressive or metastatic solid tumors.
• Secondary objective: to evaluate safety and tolerability of ATB-320 in patients with progressive or metastatic solid tumors.
• Exploratory objective: to evaluate pharmacokinetics, pharmacodynamics, and efficacy of ATB-320 in patients with progressive or metastatic solid tumors.

Inclusion criteria

• Adult (18 years or older) at the time of screening
• Histologically confirmed solid tumor
• Participants must have failed standard therapy or cannot tolerate standard therapy.
• Participants must be able to provide tissue samples, either stored at the institution or obtained from a biopsy performed prior to administration of the investigational product, and have tumor that can be safely biopsied throughout the study.
• Eastern Cooperative Oncology Group Performance Status (ECOG PS) of 0 or 1
• Life expectancy of ≥ 12 weeks

Exclusion criteria

• Has received chemotherapy within 21 days prior to the first planned dose of the investigational product, or if less than 5 times the half-life of the chemotherapeutic has passed (whichever is shorter)
• Has received immunotherapy within 2 weeks of the first planned dose of investigational product
• Major surgery within 4 weeks prior to the first planned dose of the investigational product
• Previous malignant tumors, other than the target indication to be investigated in this study, within 3 years prior to screening (participants with locally malignant tumors such as basal cell carcinoma/squamous cell carcinoma of the skin, carcinoma in situ (cervix, breast), thyroid papillary carcinoma that have undergone potentially curative therapy are eligible to participate in the study.
• Current enrollment in any other clinical trial or has received another investigational product or medical device treatment within 28 days of first planned dose (participants who are undergoing safety follow-up phase of a clinical trial may participate if more than 28 days have passed since the last dose of the previous investigational product)
• Has received prior radiotherapy within 2 weeks of the first planned dose. Participants who have received palliative radiotherapy for non-central nervous system (CNS) disease within 2 weeks of first planned dose are allowed to participate after 1-week washout (participants must have recovered from any radiation-related toxicities, not require corticosteroid treatment, and without radiation pneumonitis)
• History of hypersensitivity to the active ingredients or excipients of the investigational product or other drugs