Cisplatin + Toremifene

The combination of cisplatin and toremifene is a therapeutic regimen that has been studied primarily for non-small-cell lung cancer (NSCLC). This combination leverages toremifene's ability to potentially enhance cisplatin's cytotoxicity through protein kinase C (PKC) inhibition.\n\nThe treatment regimen typically consists of:\n- Toremifene: 600 mg orally daily on days 1-7\n- Cisplatin: 50 mg/m² intravenously on days 4 and 11\n- Treatment cycle: Repeated every 28 days.\n\nThis combination works through multiple mechanisms:\n1. **Cisplatin**: A platinum-based chemotherapy agent that damages DNA and prevents cancer cell replication.\n2. **Toremifene**: A selective estrogen receptor modulator (SERM) that:\n - Inhibits protein kinase C (PKC) signal transduction pathways\n - May downregulate c-FOS expression\n - Has tissue-specific actions (estrogenic effects on cardiovascular system and bone; antiestrogenic effects on breast tissue).\n\nThe high-dose toremifene (600 mg) used in this combination achieves plasma concentrations of approximately 14.04 μM by day 4 and 9.8 μM by day 11, which are sufficient levels for cisplatin chemosensitization and PKC modulation.\n\nIn a phase II trial of previously platinum-treated NSCLC patients:\n- Response rate: 18% (5 partial responses out of 28 evaluable patients)\n- Median overall survival: 8.1 months\n- The regimen was well-tolerated with minimal hematologic and non-hematologic toxicity.\n\nSeveral important drug interactions should be considered:\n1. **Electrolyte disturbances**: Cisplatin may cause excessive loss of magnesium and potassium in the urine.\n2. **QTc prolongation risk**: Toremifene should be used cautiously with other drugs that can prolong QT interval.\n3. **CYP3A4 interactions**: Toremifene is metabolized by CYP3A4, so inhibitors may increase its concentration.\n\nThis combination has been studied in clinical trials for metastatic non-small-cell lung cancer, particularly in patients previously treated with platinum compounds.