A Phase 1/1b Study of IAM1363 in HER2 Cancers

Inclusion Criteria

• Age ≥ 18 years
• Have relapsed/refractory HER2-altered malignancy; for selected cohorts, prospective confirmation of HER2 alteration by central testing is required
• Have progression of disease after the last systemic therapy, or be intolerant of last systemic therapy
• Have radiographically measurable disease by RECIST v1.1 and/or RANO-BM
• Eastern Cooperative Oncology Group (ECOG) performance score 0-1
• Have adequate baseline hematologic, liver and renal function
• Have left ventricular ejection fraction (LVEF) ≥ 50%
• Able to swallow oral medication Key

Exclusion Criteria

• Clinically significant cardiac disease
• Infection with human immunodeficiency virus (HIV)-1 or HIV-2. Exception: Participants with well-controlled HIV (e.g., CD4 >350/mm3 and undetectable viral load) are eligible
• Current active liver disease including hepatitis A, hepatitis B , or hepatitis C
• Refractory nausea and vomiting, malabsorption, external biliary shunt, or significant small bowel resection that would preclude adequate absorption
• Uncontrolled diabetes
• History of solid organ transplantation
• History of Grade ≥2 CNS hemorrhage, or any CNS hemorrhage within 28 days before C1D1
• Prior history of non-infectious interstitial lung disease (ILD). (Exceptions: participants with prior grade 1 ILD that has completely resolved are eligible)
• Participants requiring immediate local therapy for brain metastases