Comparing two targeted therapy drugs – is gefitinib safer than erlotinib?

This study compared two targeted therapy drugs gefitinib (Iressa) and erlotinib (Tarceva) in terms of effectiveness and safety at treating patients with advanced non-small-cell lung cancer. They concluded gefitinib was as effective as erlotinib but with fewer toxic side effects.

Current and newer treatment options for non-small cell lung cancer (NSCLC) now focus on targeting specific genetic mutations (changes) involved in cancer growth, such as the EGFR mutation. Therapies that target the EGFR mutation (EGFR TKIs) have been shown to be safe and effective and two EGFR TKIs, gefitinib and erlotinib, are now widely used to treat NSCLC. It is unclear, however, whether one is better or safer than the other.

This meta-analysis aimed to determine whether gefitinib or erlotinib were more effective and safer at treating NSCLC. The authors included 40 studies with a combined 9376 patients. 5602 patients were treated with gefitinib and 3774 patients were treated with erlotinib.

There was no significant difference between the treatments in terms of time to disease progression, survival, or response to treatment.

There was no difference in the overall number of side effects of any severity. For side effects that were grade 3 or higher (more severe), patients treated with erlotinib experienced a higher rate of side effects including skin rash, diarrhea, nausea, fatigue and stomatitis (inflammation of the mouth). Patients treated erlotinib also more frequently required dose reductions.

The authors concluded that while both therapies were equally effective at treating advanced NSCLC, gefitinib was associated with fewer serious side effects compared to erlotinib.