RecruitingDrug trialA First-in-human Dose Escalation and Expansion Study to Evaluate the Safety, and Tolerability of AZD8421 Alone or in Combination in Participants With Selected Advanced or Metastatic Solid TumorsThis study is designed to evaluate AZD8421 alone and in combination with selected targeted anti-cancer drugs in patients with ER+HER2- advanced breast cancer, and patients with metastatic high-grade serious ovarian cancer.