Table 2.
Impact of KRAS exon 2 [10] and RAS [12, 24] status on outcomes in the PRIME trial (primary analysis data)
| KRAS exon 2 WT [10] | RAS WTa [12, 24] | |||
|---|---|---|---|---|
| Panitumumab + FOLFOX4 (n = 325) | FOLFOX4 (n = 331) | Panitumumab + FOLFOX4 (n = 259) | FOLFOX4 (n = 253) | |
| Median PFS, months | 9.6 | 8.0 | 10.1 | 7.9 |
| HR [95 % CI]; p value | 0.80 [0.66–0.97]; 0.02 | 0.72 [0.58–0.90]; 0.004 | ||
| Median OS, months | 23.9 | 19.7 | 26.0 | 20.2 |
| HR [95 % CI]; p value | 0.83 [0.67–1.02]; 0.072 | 0.78 [0.62–0.99]; 0.043 | ||
| ORR,a % [95 % CI] |
n = 317 55 [50–61] |
n = 323 48 [42–53] |
n = 149 59 [52–65] |
n = 114 46 [40–53] |
| OR [95 % CI]; p value | 1.35 [NA]; 0.068 | 1.63 [1.13–2.38]; 0.009 | ||
| KRAS exon 2 MT [10] | RAS MTb [12, 24] | |||
|---|---|---|---|---|
| Panitumumab + FOLFOX4 (n = 221) | FOLFOX4 (n = 219) | Panitumumab + FOLFOX4 (n = 272) | FOLFOX4 (n = 276) | |
| Median PFS, months | 7.3 | 8.8 | 7.3 | 8.7 |
| HR [95 % CI]; p value | 1.29 [1.04–1.62]; 0.02 | 1.31 [1.07–1.60]; 0.008 | ||
| Median OS, months | 15.5 | 19.3 | 15.6 | 19.2 |
| HR [95 % CI]; p value | 1.24 [0.98–1.57]; 0.068 | 1.25 [1.02–1.55]; 0.034 | ||
| ORR,c % [95 % CI] |
n = 215 40 [33–46] |
n = 211 40 [34–47] |
NA | NA |
| OR [95 % CI]; p value | NA | NA | ||
CI confidence interval, HR hazard ratio, MT mutant, NA not available, OR odds ratio, ORR objective response rate, OS overall survival, PFS progression-free survival, WT wild type
aWild type at KRAS and NRAS exons 2 (codons 12 and 13), 3 (codon 61) and 4 (codons 117 and 146)
bMutations at any of KRAS and NRAS exons 2 (codons 12 and 13), 3 (codon 61) and 4 (codons 117 and 146). Of 620 patients with KRAS exon 2 WT tumours and RAS data, 108 (17 %) had other RAS mutations (RAS status determined using bidirectional Sanger sequencing and WAVE-based Surveyor® Scan Kits (Transgenomic)
cIncluded only patients with baseline measurable disease per central review