A phase II study of VM-26 plus lonidamine in pretreated small cell lung cancer

Background. SCLC relapsing or refractory after induction chemotherapy is a chemoresistant tumor. The outcome of salvage chemotherapy is poor, with low response rates (< 30%) and short survival times (3-4 months). The development of drug resistance is considered the major cause of failure of treatment. VM-26 is one of the most active drugs in SCLC. Lonidamine has shown to enhance in both vivo and vitro antitumor activity of several cytotoxic drugs acting on drug resistance mechanisms. Materials and methods: VM-26 and lonidamine were employed as salvage chemotherapy in 30 small cell hmg cancer patients. The doses of chemotherapy used were: VM-26 100 mg/m(2), i.v., days I to 3; lonidamine 600 mg, p.o., days I to 5, recycled every 3 weeks. Results: We observed 13.3% of objective response and a median survival of 4 months. All the responses were obtained inpatients relapsing after a response to induction chemotherapy. Toxicity was moderate with no toxic death. Conclusions: our study shows that Lonidamine failed to increase the VM-26 activity in pretreated small cell lung cancer patients.