Evaluating belotecan as an alternative treatment for topotecan for sensitive-relapsed small-cell lung cancer.

This study looked at the effectiveness and safety of belotecan (Bel; Camtobell) and topotecan (Top; Hycamtin) as therapy for sensitive relapsed small-cell lung cancer (SCLC). The authors found that Bel could be used as an alternative to Top for sensitive-relapsed SCLC. 

SCLC represents around 15% of all lung cancer diagnoses. SCLC is associated with aggressive tumors and poor prognosis. Most patients respond to chemotherapy, however, there is a high relapse rate. SCLC becomes very resistant to 1^st-line treatments very quickly. 

Top is currently the only 2^nd-line chemotherapy agent approved by the FDA to treat resistant SCLC. It is more effective in treating patients who relapse over three months following 1^st-line treatment. Bel is a newer cancer cell growth inhibitor. It works in a similar way as Top and it has been shown to be effective in treating relapsed SCLC. However, until now there has not been a comparison between the safety and effectiveness of Top and Bel for the treatment of relapsed SCLC. 

There were 148 patients with relapsed SCLC involved in this trial. 76 patients received Top and 72 patients received Bel. 

Slightly more patients experienced a response in their tumor (tumor disappearance or shrinkage) in the Bel group (33%) compared to the Top group (21%). Significantly more patients treated with Bel (85%) had disease control (tumor shrunk or stopped growing or spreading) compared to those treated with Top (70%). 

The average length of time the patients survived without their disease progressed was 4.8 months in the Bel group compared to 3.8 months in the Top group. The overall survival of patients was significantly higher with Bel (13.2 months) compared to Top (8.2 months). 58% of patients in the Bel group were alive after 12 months compared to 27% in the Top group. 

The benefit of Bel was seen particularly in patients younger than 65 years and those with extensive disease and early relapse (3-6 months after previous treatment). The occurrence of severe side effects was similar between the groups. The most common side effects experienced were low white blood cells and low platelets (clotting component of blood). 

The authors concluded that in patients <65 years old, and with more advanced disease, Bel could be used as an alternative to Top for the treatment of sensitive-relapsed SCLC.

This study was only carried out on Korean patients which may not translate well to a global population. The number of patients included was small. Further larger studies are needed. This study was funded by Chong Kun Dang Pharmaceutical, the manufacturer of Bel.