Cancer is a condition where cells in a specific part of body grow and reproduce uncontrollably. The purpose of this study is to assess the safety and efficacy of neoadjuvant carboplatin and mirvetuximab soravtansine in participants with folate receptor alpha (FRα) -expressing advanced-stage serous epithelial ovarian, fallopian tube or primary peritoneal cancer (EOC). Mirvetuximab Soravtansine (MIRV) is an investigational antibody drug conjugate designed to selectively kill cancer cells. The antibody (protein) part of MIRV targets tumors by delivering a cell-killing drug to cancer cells carrying a protein called folate receptor alpha (FRα). This is a single arm study in adult participants with advanced-stage Fédération Internationale de Gynécologie et d'Obstétrique (FIGO) III-IV FRα-expressing serous EOC. Around 140 participants will be enrolled in the study at approximately 80 sites in the United States. Participants will receive intravenous infusion of MIRV in combination with carboplatin on day 1 of each cycle, every 21 days for up to 6 - 9 Cycles. The total study duration will be approximately 3 years . There may be higher treatment burden for participants in this trial compared to their standard of care. Participants will attend regular visits during the study at a hospital or clinic and may require frequent medical assessments, blood tests, and scans.