Afatinib versus erlotinib: Comparing two second-line treatments for advanced squamous cell carcinoma

This study compared the safety and effectiveness of afatinib (Gilotrif) and erlotinib (Tarceva) as second-line treatments for advanced squamous cell carcinoma (SCC). Authors reported improved survival and disease progression with afatinib compared to erlotinib. Both treatments were associated with a good safety profile.

Squamous cell carcinoma (SCC) of the lung is one of a group of lung cancers called non-small cell lung cancer (NSCLC). Advanced SCC accounts for about 20 to 30% of cases of NSCLC. SCC starts in the cells that line the inner airways of the lungs (the squamous cells) and develops in the central regions of the lungs. Progress in treatment options for advanced SCC lags behind that of adenocarcinoma, another type of NSCLC.

First-line treatments for advanced SCC typically include chemotherapy combinations, such as cisplatin (Platinol)-gemcitabine (Gemzar). However, SCC can continue to progress despite standard chemotherapy. Erlotinib and afatinib are biological therapies that target certain proteins on some cancer cells. Many NSCLC patients have a mutated epidermal growth factor receptor (EGFR) gene. Erlotinib and afatinib decrease or block the activity of EGFR, which slows cancer cell production.

The aim of this study was to compare erlotinib and afatinib as second-line treatments for patients with advanced SCC of the lung.

795 patients with advanced SCC (stage 3b or 4) were randomly assigned to receive either erlotinib or afatinib. All patients had SCC progressing after at least 4 cycles of platinum-based chemotherapy. Patients were followed for an average of 18.4 months.  

Overall survival (time from treatment until death from any cause) was significantly improved with afatinib (average 7.9 months) compared to erlotinib (average 6.8 months). The 12-month overall survival rate was 36.4% with afatinib. This was significantly greater than 28.2% with erlotinib. Overall, patients receiving afatinib were 19% more likely to survive the study period. This remained significant across gender, ethnicity, type of chemotherapy received, interval until second-line treatment, smoking status, and subtype of SCC. There was a trend for younger patients (aged less than 65) to show a greater survival benefit with afatinib than older patients (aged 65 or older).

Progression-free survival was also significantly improved with afatinib (average 2.6 months) compared to erlotinib (average 1.9 months). Overall, patients receiving afatinib were 18% more likely to have no signs of disease progression during the study period. Treatment response was observed in 51% of patients receiving afatinib. This was significantly greater than 40% of patients receiving erlotinib.

No differences in the rate of side effects was noted between erlotinib and afatinib. The most common side effects included diarrhea, rash or acne, skin irritation, fatigue, and an inflammation of the mouth. Most side effects were considered mild. Serious side effects included diarrhea, dehydration, and kidney failure (reported in less than 4% of cases).

Authors concluded that afatinib offers a survival benefit over erlotinib as a second-line treatment for advanced SCC.