Cetuximab Improves Efficacy of Cisplatin/Vinorelbine in EGFR-Positive NSCLC Patients

BARCELONA-Adding cetuximab(Drug information on cetuximab) (Erbitux) improves the efficacy of cisplatin(Drug information on cisplatin)/vinorelbine (Navelbine) for first-line treatment of advanced non-small-cell lung cancer (NSCLC) in patients whose tumors express epithelial growth factor receptor (EGFR), according to Rafael Rosell, MD, of the Catalan Institute of Oncology, Barcelona, Spain. Dr. Rosell reported that data from a randomized phase II study also showed that development of a skin rash is predictive of response and that the toxicity of the regimen was not increased substantially by adding cetuximab (abstract 7012). Cetuximab is an IgG1 monoclonal antibody targeting the EGFR. Dr. Rosell said that combinations of cetuximab and chemotherapy have been shown to be effective and safe in other EGFR-expressing tumors such as colorectal and head and neck cancers. Predominantly Stage IV The primary study endpoint was objective response rate. Ninety percent of the patients in this study had stage IV disease. All patients were treated with three cycles of cisplatin 80 mg/m² on day 1 and vinorelbine 25 mg/m² on days 1 and 8. Patients were then randomized to receive either additional treatment with cetuximab 400 mg/m² on week 1 and 250 mg/m² weekly thereafter (arm A, n = 43), or no additional treatment (arm B, n = 43). Ninety percent (101 of 122 patients screened) had EGFR expressing tumors. A total of 86 patients were enrolled, 43 in each of the two treatment arms. One-year survival was 32% with cetuximab plus chemotherapy vs 29% with placebo plus chemotherapy, but Dr. Rosell emphasized that only five patients are still alive. Survival at 18 months was 14% with cetuximab vs 0 on the comparison arm. "The longest survival was 24 months," he said. The patients who were treated with cetuximab had more grade 3 or 4 asthenia and fatigue (19% vs 2%). Complete/Partial Responses For patients under age 60 years, the unconfirmed complete response/partial response rate was 63% for patients treated with cetuximab vs 2% for controls. In the same population, confirmed complete/partial responses were 14% with cetuximab, 0 without cetuximab. For patients over age 60 years, the unconfirmed complete response/partial response rate was 31% with cetuximab vs 36% without cetuximab. Dr. Rosell said that the response rate was 25% in patients who developed any type of skin toxicity. "Cetuximab can safely be added to the regimen of cisplatin and vinorelbine, with evidence suggesting enhancement of activity," Dr. Rosell concluded.