Afatinib in lung cancer patients with uncommon EGFR mutations

The authors aimed to determine the effect of afatinib (Gilotrif) in lung cancer patients with advanced (cancer has spread),  uncommon epidermal growth factor receptor (EGFR) mutations.

EGFR mutations are found in 15% of lung cancer patients. Certain EGFR mutations can predict whether drugs, such as tyrosine kinase inhibitors (TKI – stop the proteins responsible for cell growth) will work. Afatinib is a TKI biological therapy (enhances the immune system) drug that is used to treat metastatic (cancer that has spread to other parts of the body) lung cancer. In particular it is used to treat lung cancer with a specific EGFR mutation (exon 19 deletion/exon 21 substitution).

The aim of this study was to determine the effect of afatinib in treating lung cancer patients with specific, uncommon EGFR mutations.

75 patients with uncommon EGFR mutations were included in this study. These patients were placed into three groups. 38 patients in group 1 had mutations in exons (part of the DNA and RNA in the cells) 18-21. 14 patients in group 2 had specific mutations in exon 20 alone or in combination with other mutations. 23 patients in group 3 had extra exon 20 insertions (another type of mutation).

27 patients in group 1 and 2 patients from both group 2 and group 3 had an objective response to treatment (tumor shrank in size but was not completely cured). The average progression-free survival (time from treatment until cancer progressed) was 10.7 months in group 1, 2.9 months in group 2 and 2.7 months in group 3. Overall survival (time from treatment that patients were still alive) was 19.4 months in group 1. It was 14.9 months in group 2 and 9.2 months in group 3. Afatinib was particularly effective in patients with Gly719Xaa, Leu861Gln and Ser768Ile mutations.

The authors concluded that afatinib was effective in patients with uncommon EGFR mutations, particularly patients with Gly719Xaa, Leu861Gln and Ser768Ile mutations.