Table 4.
Progression-free and overall survival outcomes by tumour shrinkage at week 8 (RAS wild-type population – between treatment comparisons)
| Tumour shrinkage at week 8 | ||||
|---|---|---|---|---|
| Panitumumab + mFOLFOX6 | Bevacizumab + mFOLFOX6 | Panitumumab + mFOLFOX6 | Bevacizumab + mFOLFOX6 | |
| <30% | ≥30% | |||
| Patients with shrinkage, n (%) | 29 (36) | 41 (55) | 51 (64) | 33 (45) |
| Odds ratio* (95% CI) | 1.99 (0.99, 4.10) | |||
| p value | 0.052 | |||
| Median PFS, months (95% CI) | 11.6 (7.5, 15.4) | 9.7 (7.5, 12.9) | 13.0 (10.9, 18.1) | 11.1 (9.0, 16.6) |
| HR (95% CI) | 0.79 (0.45, 1.38) | 0.74 (0.45, 1.23) | ||
| p value | 0.40 | 0.24 | ||
| Median OS, months (95% CI) | 34.2 (17.5, 42.3) | 23.9 (20.1, 29.0) | 43.8 (36.4, 63.0) | 35.1 (29.9, NE) |
| HR (95% CI) | 0.75 (0.43, 1.31) | 0.77 (0.42, 1.42) | ||
| p value | 0.31 | 0.41 | ||
| <20% | ≥20% | |||
| Patients with shrinkage, n (%) | 20 (25) | 28 (38) | 60 (75) | 46 (62) |
| Odds ratio* (95% CI) | 1.67 (0.78, 3.58) | |||
| p value | 0.21 | |||
| Median PFS, months (95% CI) | 9.8 (4.2, 15.4) | 9.5 (7.4, 12.7) | 13.1 (10.9, 16.2) | 11.3 (9.2, 13.6) |
| HR (95% CI) | 0.99 (0.50, 1.95) | 0.70 (0.45, 1.08) | ||
| p value | 0.97 | 0.11 | ||
| Median OS, months (95% CI) | 21.2 (14.1, 41.2) | 21.8 (15.3, 28.9) | 43.4 (36.4, 55.4) | 32.5 (27.7, 47.4) |
| HR (95% CI) | 0.81 (0.42, 1.57) | 0.73 (0.44, 1.19) | ||
| p value | 0.53 | 0.21 | ||
*Odds ratio is defined as the odds of having ≥30 or ≥20% tumour shrinkage in the panitumumab + mFOLFOX6 arm relative to the odds in the bevacizumab + mFOLFOX6 arm
CI confidence intervals, HR hazard ratio, NE not evaluable, OS overall survival, PFS progression-free survival