Example of comparative evidence from phase II and III trials: thalidomide and advanced small-cell lung cancer
| Two small single-arm phase II trials and a small randomised placebo-controlled trial reported consistent evidence to suggest that thalidomide could greatly increase overall survival when used with standard chemotherapy. Patients lived noticeably longer than expected. |
| The 1-yr survival rate in these three studies were 46 (n = 25), 52 (n = 30) and 49% (n = 49); all higher than the expected value of 20–30%. |
| In the small randomised trial (based on administering thalidomide to patients who had already responded to standard chemotherapy), the median survival was 11.7 (n = 49) and 8.7 (n = 43) months in the thalidomide and placebo arms, respectively; which was a substantial difference. |
| However, a large double-blind placebo-controlled phase III trial (n = 724) of thalidomide versus placebo was conducted. The results showed no evidence of an effect. The median survival was 10.1 and 10.5 months in the thalidomide and placebo arms, respectively. The 1-yr survival rates were 37 and 41%, respectively. |