Optimal drugs for second-line treatment of patients with small-cell lung cancer.

INTRODUCTION: Despite the high response rate to chemotherapy, there have been few advances in the treatment of small-cell lung cancer (SCLC) in the last decades. The state-of-the-art second-line therapy and future research developments in relapsed SCLC are reviewed. AREAS COVERED: There are no optimal drugs for second-line treatment of recurrent SCLC but only agents registered for this use. Topotecan remains the standard-of-care for the treatment of second-line platinum-sensitive SCLC patients worldwide, while amrubicin is another option, but registered only in Japan. To date, no targeted agents reporting interesting results in second-line SCLC treatment are available. The next-generation DNA sequencing should discover somatic gene alterations and their roles in SCLC to help in selecting patients who could benefit from a targeted agent. Two immunotherapeutics, ipilimumab and nivolumab, have shown promising preliminary results and are being investigated in ongoing trials. EXPERT OPINION: Second-line treatment is not an option for most SCLC patients. Given the evidence up to now, the potentials for immuno-oncology in SCLC are high. The hope is that these expectations are met, and that all drugs being developed will offer new and improved treatment options for SCLC patients.