• Pathologically documented, definitively diagnosed, advanced solid tumour that is refractory to all standard treatment, for which no standard treatment is available, or it is contraindicated, or the patient refuses standard therapy.

• Measurable or evaluable disease in accordance with RECIST 1.1.

• Eastern Cooperative Oncology Group (ECOG) Performance status of 0 or 1.

• Life expectancy of greater than 3 months as judged by the treating physician.

• Available tumour tissue (either archival or fresh biopsy) for IGF-1R immunohistochemistry. Submission of the tissue is not required prior to enrollment.

• Adequate heart, kidney, and liver function

• Adequate bone marrow reserves

• Ability to understand and the willingness to sign a written informed consent document.

• Phase 2 Specific

• Histologically and/or cytologically documented diagnosis of locally advanced, inoperable, metastatic, or recurrent solid tumour types: endometrial, cervical, ovarian, TNBC, HER 2-negative breast, HNSCC, ACC, or uveal melanoma.

⁃ Have measurable disease per RECIST 1.1 Failure to respond to standard systemic therapy, or for whom standard or curative systemic therapy does not exist or is not tolerable.

⁃ Imaging Eligibility

⁃ Prior to the initial \[225Ac\]-FPI-1434 cycle: Sufficient target expression in at least 1 lesion following \[111In\]-FPI-1547 and SPECT imaging.