Irinotecan (Camptosar) in combination with cisplatin(Drug information on cisplatin) (Platinol) increased survival, compared with the current standard treatment for patients with extensive small-cell lung cancer, according to data from a phase III study presented at the annual meeting of the American Society of Clinical Oncology (ASCO).
Significant Survival Benefit
This randomized, multicenter Japanese trial enrolled 154 patients and was designed with survival as the primary end point. Among patients receiving irinotecan(Drug information on irinotecan) and cisplatin, 60% lived 1 year or longer compared with 40% of those receiving standard treatment with etoposide(Drug information on etoposide) and cisplatin. The study was stopped at a preplanned interim analysis point due to the survival benefit in the irinotecan arm of the study.
Patients receiving the regimen containing irinotecan had a median survival of 390 days vs 287 days for the standard-treatment arm (P = .0021). The 2-year survival rate for patients receiving irinotecan and cisplatin was 19%, compared with 6.5% for patients receiving standard treatment.
Treatment advances in small-cell lung cancer have been few and far between, said Nagahiro Saijo, MD, chairman of medical oncology at the National Cancer Center Hospital in Japan and the Lung Cancer Study Group of the Japanese Clinical Oncology Group. Dr. Saijo is the lead investigator of the lung cancer trial for irinotecan in Japan. Significantly increased survival rates among patients being treated with irinotecan and cisplatin led us to halt the study early, he said.
Severe Side Effects Reduced
Safety data from the phase III study showed that patients receiving irinotecan and cisplatin experienced a 5% incidence of severe thrombocytopenia, a 27% incidence of severe leukopenia, and a 66% incidence of severe neutropenia. Comparatively, patients receiving standard therapy experienced a 19% incidence of severe thrombocytopenia, a 52% incidence of severe leukopenia, and a 92% incidence of severe neutropenia. For the patients receiving irinotecan and cisplatin, this represents a 74% reduction in the incidence of thrombocytopenia, a 48% reduction in the incidence of leukopenia, and a 28% reduction in the incidence of severe neutropenia. Severe diarrhea occurred in 16% of patients receiving irinotecan, compared with no patients in the standard therapy group. Other nonhematologic side effects did not differ between treatment arms.
Camptosar was recently approved by the FDA for the first-line treatment of metastatic colorectal cancer based on its ability to improve survival, said Alan Sandler, md, medical director of the Thoracic Oncology Program at Indiana University School of Medicine. The results from this trial showed a significant survival benefit from Camptosar in extensive small-cell lung cancer.