Table 3 Treatment outcome to afatinib and resistance mechanism identified at disease progression
| Treatment outcome |
Total number of patients (n = 85) |
|---|---|
| Best tumor response, No. (%) | |
| Complete response | 2 (2.4) |
| Partial response | 63 (74.1) |
| Stable disease | 16 (18.8) |
| Progressive disease | 4 (4.7) |
| Disease progression site, No. (%) | |
| None | 29 (34.1) |
| New brain lesions | 7 (8.2) |
| New lesions at other sites | 49 (57.6) |
| Investigation for resistance mechanism, No. (%) | |
| No progression | 29 (34.1) |
| Not investigated | 25 (29.4) |
| Investigated | 31 (36.5) |
| -Exon 20 T790 M mutation detected | 13 (42.0) |
| -Exon 20 T790 M mutation not detected and no histologic transformation | 18 (58.0) |