Justification for evaluating new anticancer drugs in selected untreated patients with extensive-stage small-cell lung cancer: an Eastern Cooperative Oncology Group randomized study

Abstract

Background: Studies have shown that response to a given chemotherapy in previously untreated patients with extensive-stage small-cell lung cancer is superior to that in patients previously treated with other regimens. This finding raises the question of whether it is necessary and ethical to study the effects of new anticancer agents in untreated patients. Such studies appear to be the best test for drug development, but there has been no evaluation of whether survival of untreated patients, whose cancer is sensitive to established drugs, is adversely affected in trials of new drugs.

Purpose: This randomized study of untreated patients with extensive-stage small-cell lung cancer was designed (a) to compare the survival of patients treated with either effective standard chemotherapy or an investigational anticancer drug as initial therapy and (b) to evaluate response rates and toxic effects of such therapies.

Methods: Eighty-six patients were randomly assigned to receive, as initial therapy, either the standard CAV regimen--cyclophosphamide (1000 mg/m2), doxorubicin (50 mg/m2), and vincristine (1.4 mg/m2) every 3 weeks--or the phase II drug menogaril (200 mg/m2) every 4 weeks. Treatment after induction therapy varied, depending on patient response, but nonresponders and those with disease progression received salvage chemotherapy--etoposide (120 mg/m2 on days 1, 2, and 3) and cisplatin (60 mg/m2 on day 1), repeated every 3 weeks.

Results: Of the 43 patients on CAV, 42% responded (eight complete responses and 10 partial responses); 5% of the 43 on menogaril responded (two partial responses) (P = .0001). Twelve (22%) of 54 patients responded to salvage chemotherapy (five complete responses and seven partial responses). Within 3 months from start of treatment, twelve patients died--3 patients in the CAV group and nine patients in the menogaril group (P = .12). The estimated median survival was 37 weeks with menogaril and 45 weeks with CAV (P = .28). At 6 months, survival was 76.7% for the CAV group and 67.4% for the menogaril group. At 12 months, survival rates were 24.4% and 27.9%, respectively. Confidence intervals (95%) for the differences between the proportions surviving in the two groups were -9%-28% at 6 months and -25%-14% at 12 months. Use of CAV resulted in significantly higher occurrence of severe and life-threatening treatment-related complications (P = .002).

Conclusion: The confidence intervals for the differences in survival are too wide to conclude that evaluation of a new drug in untreated patients with extensive-stage small-cell lung cancer is or is not harmful. The data do suggest, however, that use of this study design may have no adverse effect on survival.