A Phase 1/2, Open-Label, Multicenter, Dose-Escalation, and Dose-Optimization Study to Evaluate the Safety, Tolerability, and Activity of EIK1004 (IMP1707) as Monotherapy in Participants with Advanced Solid Tumors.

• Breast cancer: must have received at least one prior chemotherapy in neoadjuvant/adjuvant/metastatic setting, must have received hormonal therapy if HR+, HGSOC or high grade endometrioid EOC, fallopian tube or primary peritoneal cancer; must have received at least one prior platinum-based chemotherapy for advanced disease. mCRPC with ongoing ADT, must have received NHA and up to 1 prior line of taxane chemotherapy; Pancreatic cancer, must have prior 1L therapy - Age ≥ 18 years at the time of informed consent - Eastern Cooperative Oncology Group (ECOG) performance status ≤1 - Adequate organ function - Life expectancy ≥ 12 weeks - Should have evaluable disease as defined by RECIST1.1 and/or CA125 or PSA - Female subjects of childbearing potential and male subjects must agree to use an effective method of contraception from study entry up to 6 months after the last dose of EIK1004 (IMP1707) - Deleterious or suspected deleterious germline or somatic mutations of select HRR genes - Up to 1 prior line of PARP inhibitor containing treatment CNS Inclusion Criteria: - Untreated CNS metastases (measurable and/or non-measurable) not needing immediate local therapy. - Previously treated CNS metastases Key Exclusion Criteria: - Any investigational or approved anti-cancer therapies administered within 28 days/ before the first dose of EIK1004 (IMP1707) - Have received prior PARP1 selective inhibitors - Mean resting QTcF > 470 ms or QTcF < 340 ms - Infections - An active hepatitis B/C infection - Any known predisposition to bleeding - Unable to swallow oral medications OR have malabsorption syndrome or any other uncontrolled gastrointestinal condition that might impair the bioavailability CNS Exclusion Criteria - Any untreated brain lesions > 2.0 cm in size. - Ongoing use of systemic corticosteroids for control of symptoms of CNS metastases < 7 days prior to the first dose of study treatment or requirement for > 10 mg prednisone/day. - Any brain lesion requiring immediate local therapy, including (but not limited to) a lesion in an anatomic site where an increase in size or possible treatment-related edema may pose risk to the participant (eg, brain stem lesions). - Known, symptomatic leptomeningeal disease. - Have poorly controlled seizures.