NEW YORK (Reuters Health) – In patients with untreated advanced non-small-cell lung cancer (NSCLC), adding cetuximab (Erbitux) to platinum-based chemotherapy can improve overall survival and response rates, a new meta-analysis suggests.
Still, for these patients, the “choice of cetuximab-chemo or chemo alone…depends on the absolute difference of clinical benefit more than whether it formally achieves statistical significance or not,” the researchers emphasize.
According to their report in the online issue of Lung Cancer, patients treated with cetuximab plus chemo had significantly better overall survival (HR, 0.87, p = 0.004). In the four trials they analyzed (2 phase II, 2 phase III), median survival ranged from 8.3 to 11.9 months with cetuximab and 7.3 to 10.1 months without it.
Cetuximab also improved the overall response rate (RR, 1.19, p = 0.013), according to Dr. Xiaohua Liang and colleagues from Fudan University in Shanghai. Response rates with cetuximab ranged from 27.5% to 37%, whereas control groups had rates of 18% to 29%. Complete responses, even with cetuximab, were rare.
By contrast, cetuximab did not seem to improve 1-year survival or progression-free survival. With or without it, median progression-free survival hovered closely around 4.5 months. Three trials reported 1-year survival, which ranged from 33% to 50% with cetuximab and from 26% to 42% in controls.
The four trials included in the review and meta-analysis were identified through a search of MEDLINE and other sources and included 2018 patients with previously untreated NSCLC. Chemotherapy regimens included cisplatin plus vinorelbine in 2 trials, cisplatin plus gemcitabine in 1, and carboplatin plus paclitaxel in 1.
Grade 3/4 rash and infusion reaction were significantly more common with cetuximab, the report indicates, but were “predictable and manageable”.
But “whether the difference in overall survival…has clinical significance” is not clear, the authors write.
However, they point out, “since (the) U.S. Food and Drug Administration takes overall survival as the major endpoint for cancer drug approvals and progression-free survival as surrogate for overall survival in the first-line treatment of NSCLC, our study showed that addition of cetuximab to chemotherapy may provide new opportunities for clinical treatment” of this disease.
Also unclear are the optimum duration of treatment and how to tell which patients are most likely to benefit, the authors conclude. “So far, it is difficult to determine a factor that can best predict the sensitivity of cetuximab for NSCLC.”
Lung Cancer 2010.