Study of RP-3500 (Camonsertib) With Niraparib or Olaparib in Advanced Solid Tumors

Inclusion Criteria: * Male or female and ≥18 years-of-age at the time of signature of the informed consent * Confirmed advanced solid tumors resistant or refractory to standard treatment * Eastern Cooperative Oncology Group (ECOG) Performance Status score of 0 or 1. * Evaluable disease as per RECIST v1.1 * Next generation sequencing (NGS) report obtained in CLIA-certified or equivalent laboratory demonstrating eligible tumor biomarkers. * Submission of available tumor tissue or willingness to have a biopsy performed if safe and feasible * Acceptable hematologic and organ function at screening * Negative pregnancy test for women of childbearing potential at Screening and prior to first study drug. * Ability to swallow and retain oral medications. Exclusion Criteria: * Prior therapy with an ATR or DNA-dependent protein kinase (DNA-PK) inhibitor. * Chemotherapy, small molecule anticancer or biologic anticancer therapy given within 10 days or 5 half-lives (whichever is longer), prior to first dose of study drug. * Use of radiotherapy (except for palliative reasons) within 7 days prior to first dose of study drug. * History or current condition, therapy, or laboratory abnormality that might confound the study results, or interfere with the patient's participation for the full duration of the study treatment. * No other anticancer therapy is to be permitted while the patient is receiving study treatment. * Major surgery ≤28 days or minor surgical procedures ≤7 days prior to first study treatment dose. * Uncontrolled, symptomatic brain metastases. * Uncontrolled high blood pressure * History of myelodysplastic syndrome (MDS) or acute myeloid leukemia (AML) diagnosis * Presence of other known active invasive cancers. * Pregnant or breastfeeding women. * Psychological, familial, sociological, or geographical conditions that do not permit compliance with the study protocol and/or follow-up procedures outlined in the protocol.