Table 2.
Patient characteristics at the start of osimertinib treatment
| Group A (n = 8) | Group B (n = 30) | ||
|---|---|---|---|
| n (%) | n (%) | P‐value | |
| Sex | 0.767 | ||
| Male | 3 (38) | 13 (43) | |
| Female | 5 (62) | 17 (57) | |
| Age | |||
| Median (range) | 66.5 (47–78) | 69.5 (39–83) | 0.622 |
| Performance status | 0.275 | ||
| 0–1 | 8 (100) | 26 (87) | |
| 2 | 0 | 4 (13) | |
| Smoking status | 0.767 | ||
| Never | 5 (62) | 17 (57) | |
| Previous/current | 3 (38) | 13 (43) | |
| Histology | |||
| Adenocarcinoma | 8 (100) | 30 (100) | |
| Brain metastasis | 0.611 | ||
| Present | 4 (50) | 12 (40) | |
| Absent | 4 (50) | 18 (60) | |
| Status of EGFR activating mutation | 0.898 | ||
| Exon 19 deletion | 5 (62) | 18 (60) | |
| L858R | 3 (38) | 12 (40) | |
| Specimen to be measured T790M | 0.129 | ||
| Tissue | 6 (75) | 17 (57) | |
| Cytology | 0 | 10 (33) | |
| Plasma | 2 (25) | 3 (10) | |
| Last EGFR‐TKI before osimertinib treatment | < 0.001 | ||
| Afatinib | 7 (88) | 0 | |
| Gefitinib | 1 (12) | 12 (40) | |
| Erlotinib | 0 | 18 (60) | |
| Number of prior regimens | 0.034 | ||
| 1–2 | 2 (25) | 20 (67) | |
| 3– | 6 (75) | 10 (33) | |
| Total treatment duration with EGFR‐TKIs before osimertinib administration | 0.737 | ||
| Median, months (95% confidence interval) | 24.9 (13.2–40.6) | 19.3 (15.7–34.1) | |
| Period between end of pretreatment EGFR‐TKI and osimertinib administration | 0.351 | ||
| Median, days (95% confidence interval) | 1 (1–20) | 1 (1–8) | |
Group A; pretreated with afatinib before osimertinib treatment, Group B; pretreated with first‐generation EGFR‐TKI before osimertinib treatment.