A Phase 1 Dose Escalation and Expansion Study of EO-3021, an Anti-claudin 18.2 (CLDN18.2) Antibody Drug Conjugate, in Patients With Solid Tumors Likely to Express CLDN18.2

Key Inclusion Criteria:

• Availability of tumor tissue (archived and fresh tumor biopsy, if medically feasible)
• Select advanced or metastatic solid tumor that is likely to express CLDN18.2 such as gastric/GEJ, pancreatic and esophageal cancer
• ≥ 18 years of age
• ECOG performance status (PS) 0 or 1 at Screening
• Progressed on or after standard therapy, or are intolerable for available standard therapy, or there is no available standard therapy
• Have at least one measurable extra-cranial lesion as defined by RECIST v1.1
• Adequate organ function
• Life expectancy > 12 weeks
• Ability to understand the nature of this study, comply with protocol requirements, and give written informed consent
• Willingness of men and women of reproductive potential to observe conventional and effective birth control for the duration of treatment and for 3 months following study completion

Key Exclusion Criteria:

• Pregnant or breastfeeding
• Symptomatic or untreated brain metastases
• Have previously received CLDN18.2 antibody drug conjugates (ADCs) or any ADC containing an auristatin payload (prior monoclonal antibody against CLDN18.2 may be eligible)
• Have peripheral neuropathy Grade ≥2
• Have history of non-infectious pneumonitis/interstitial lung disease
• Have diagnosis of another malignancy, or history of systemic treatment for invasive cancer within last 3 years. Note: Patients with Stage I cancer who have received definitive local treatment and are considered unlikely to recur are eligible. Diagnosis of non-melanoma skin cancer, carcinoma in situ of the cervix or breast, or noninvasive tumor does not affect eligibility
• Have active ocular surface disease at baseline (based on screening ophthalmic examination)
• Have serious concurrent illness or clinically relevant active bacterial, fungal or viral infection
• Have previous hypersensitivity to any known components of EO-3021 or history of severe infusion reaction or hypersensitivity (CTCAE Grade 3 or higher) with monoclonal antibody treatment
• Clinically significant cardiac disease, including but not limited to symptomatic congestive heart failure, unstable angina, acute myocardial infarction within 6 months of planned first dose, or unstable cardiac arrhythmia requiring therapy (including torsades de pointes)
• Have history of allogenic hematopoietic stem cell transplantation or solid organ transplantation with ongoing systemic immunosuppressive therapy
• Patients who are not appropriate candidates for participation in this clinical study for any other reason as deemed by the Investigator