This is the first study where BAY1000394 is given in combination with chemotherapy: cisplatin / etoposide or carboplatin / etoposide. Patients with small cell lung cancer will be treated. Every patient will receive drug treatment, there is no placebo group. Different groups of patients will receive different dosages of BAY1000394 to determine the safety and maximum tolerated dose (MTD) of BAY1000394 in combination with chemotherapy. The dose of chemotherapy is the standard dose usually administered and will not change.