thiotepa + vinorelbine

A combination chemotherapy regimen consisting of thiotepa and vinorelbine. Thiotepa is an alkylating agent that cross-links DNA strands, while vinorelbine is a vinca alkaloid that disrupts microtubule assembly. This combination has shown activity in metastatic breast cancer as second-line treatment and has been used in protocols for relapsed/refractory acute leukemia. It provides an anthracycline-free option that may help minimize drug resistance. ## Efficacy and Clinical Use In metastatic breast cancer, a phase II trial evaluated thiotepa + vinorelbine as second-line treatment in patients who had previously received anthracycline-based chemotherapy. The study showed an overall response rate of 28% (including two complete responses and seven partial responses) among 32 evaluable patients. The median duration of response was 9 months, and the median time to progression was 6 months[1]. This combination appears particularly promising for patients with cerebral and/or leptomeningeal metastasis in metastatic breast cancer[4]. It's considered a reasonable option for patients with metastatic disease who have already been treated with anthracyclines[1]. ## Dosing and Administration In the phase II trial for metastatic breast cancer, the regimen consisted of: - Vinorelbine 30 mg/m² on days 1 and 8 - Thiotepa 12 mg/m² on days 1 and 8 - Administered every 21 days[1] When used in leukemia protocols, the combination is often part of more complex regimens that may include additional agents like topotecan, clofarabine, and dexamethasone[2][6][7][8]. ## Toxicity Profile The main toxicities observed with this combination include: - Leukopenia (72%) - Anemia (48%) - Local phlebitis (39%)[1] Despite these side effects, the combination has been reported to be well-tolerated overall[1]. ## Mechanism of Action Thiotepa is an alkylating agent that works by cross-linking DNA strands, preventing cell division. It's used in various malignancies including adenocarcinomas and superficial bladder carcinomas, and also in stem cell transplantation to prevent graft rejection[5]. Vinorelbine is a vinca alkaloid that disrupts microtubule assembly, preventing cell division. The combination provides an anthracycline-free chemotherapeutic regimen of novel active agents, which may help minimize the risk of drug resistance[2].