An international team of researchers has shown that adding erlotinib (Tarceva) to bevacizumab (Avastin)
maintenance therapy after initial treatment with chemotherapy and bevacizumab in patients with advanced nonsmall cell lung cancer delays disease progression better than bevacizumab alone.

"There is ongoing interest among medical oncologists about the potential role of maintenance therapy for patients with advanced non-small cell lung cancer," said Dr. Vincent A. Miller, Associate Attending Physician on the Thoracic Oncology Service at Memorial Sloan-Kettering Cancer Center and lead author of the study, known as ATLAS, being presented at the American Society of Clinical Oncology. "Bevacizumab is a core component of the treatment of advanced non-small cell lung cancer (NSCLC), and we’ve shown here we can delay progression with the addition of a targeted agent, erlotinib. Critical future work will try to determine which patients will get the greatest benefit from this combination, based in large part on the identification of genetic biomarkers."

Maintenance therapy, a relatively new concept in NSCLC, refers to the continuation of one or more agents of a chemotherapy regimen but not the whole regimen to delay progression of disease and potentially improve survival after patients have received several months of stronger standard chemotherapy, which can carry significant side effects. This is the first study to show that adding erlotinib to maintenance therapy with bevacizumab delays disease progression in patients who have already received bevacizumab as part of their initial chemotherapy. Both bevacizumab and erlotinib have fewer side effects than traditional cytotoxic chemotherapy.

Previous research has shown that bevacizumab along with chemotherapy improved progression-free and overall survival among patients with advanced, metastatic, or recurrent non-squamous NSCLC when compared to chemotherapy alone. In that study, bevacizumab was continued after chemotherapy until disease progression. The purpose of the current study was to determine if progression could be further delayed by the addition of erlotinib.

In this randomised, double-blind, phase III trial, 768 patients were randomised to receive bevacizumab plus erlotinib or bevacizumab plus placebo. All patients had already received four cycles of chemotherapy and bevacizumab as first-line therapy. Patients who had not progressed then continued bevacizumab and were blinded and randomised to receive placebo or erlotinib.

This study reports the results of the trial’s second planned interim analysis of the data, which identified a statistically significant improvement in efficacy, favouring the erlotinib group; the trial was stopped early based on these findings. Patients in the erlotinib group experienced a 29 per cent reduced risk of disease progression. Median progression-free survival (the time it took for the cancer to get worse) was 4.8 months for patients in the erlotinib plus bevacizumab group, compared with 3.7 months for patients in the bevacizumab-placebo group.There were no unexpected side effects in either arm.