The overexpression of HER-2 occurs in a minority of patients with nonsmall cell lung carcinoma. Trastuzumab, which is a monoclonal antibody to HER-2, is an effective treatment in some women with breast carcinomas that overexpress HER-2, as demonstrated by immunohistochemistry. The objective of this Phase II study was to determine whether trastuzumab would effect responses in patients with nonsmall cell lung carcinoma who had tumors that overexpressed HER-2.

Patients were required to have Stage IIIB or Stage IV nonsmall cell lung carcinoma and tumors with 2+ or 3+ expression of HER-2, as determined with immunohistochemistry, and they may have received up to 1 prior chemotherapy regimen. Trastuzumab at a dose of 4 mg/kg was given intravenously on Week 1; then, weekly doses of 2 mg/kg were given. Response revaluation was performed every 8 weeks.

Among 209 screened patients, 24 patients (11%) had tumors with 2+ or 3+ expression of HER-2. One patient achieved a partial response, and one patient experienced a treatment-related death due to pulmonary toxicity.

Single-agent trastuzumab did not exhibit significant clinical activity against nonsmall cell lung carcinoma when HER-2 expression levels were measured by immunohistochemistry.