Cetuximab Active as Monotherapy for Recurrent NSCLC

BOSTON-Early data from a phase II trial show that cetuximab(Drug information on cetuximab) (Erbitux) is active as monotherapy for recurrent non-small-cell lung cancer (NSCLC). The planned interim analysis, presented by Thomas J. Lynch, MD, of Massachusetts General Hospital, Boston, also revealed that the activity is not related to any previously identified mutations in the epithelial growth factor receptor (EGFR) (abstract 7084). The phase II trial was undertaken because the addition of cetuximab to chemotherapy produced promising results in doublet and triplet combi- nations, but single-agent activity in NSCLC had not been established. The trial enrolled patients with stage IIIB/ IV NSCLC who have recurrent or metastatic disease following one or more prior regimens, including prior platinum- based therapy. The original protocol allowed tumors to be either EGFR positive or negative but was amended to EGFR-positive only due to slow accrual of EGFR-negative patients. The trial has now closed to enrollment with a total of 61 EGFR-positive patients and 6 EGFR-negative patients. Investigators administered an initial cetuximab dose of 400 mg/m² on day 1 of cycle 1, followed by four weekly doses of 250 mg/m² of cetuximab. Each cycle is defined as 4 weeks. Treatment in the ongoing study continues until disease progression or unacceptable toxicity develops. Most patients had stage IV disease, and mean age was 64 years (range 40- 78). The mean number of cycles that had been received by the interim analysis was three, with a range of one to six. One patient each had grade 3 or 4 rash, cellulitis, fatigue, or nausea and vomiting, and these adverse events were considered to be possibly related to cetuximab. Drug Is Active The interim analysis of the first 33 EGFR-positive patients identified two patients (6%) with confirmed partial responses and seven patients (21%) with stable disease. "This shows that the drug is active but doesn't tell you any more than that," Dr. Lynch commented. He noted, however, that stable disease does confer a survival advantage. Interestingly, he reported that although response to gefitinib(Drug information on gefitinib) (Iresssa) correlates with some mutations in the EGFR, analysis of responders vs nonresponders among patients in this study did not reveal a similar relationship with cetuximab. "In the sample size analyzed," Dr. Lynch told Oncology News International, "previously characterized EGFR mutations do not seem to have an effect on response to cetuximab."