Table 2

Effect of combining anti-VEGF antibody and ionizing radiation

TumorDaybFractional tumor volume relative to untreated controlsa
Ionizing radiationAnti-VEGF antibodyCombined (expected)cCombined (observed)Observed/expectedd
LLC60.5700.5740.3270.2200.673
Seg-1130.1980.7780.1540.0690.448
SQ20B190.5120.7150.3660.1820.497
U87180.3021.0000.3020.1660.550
  • a Obtained by dividing the mean volume of treated tumors by that of untreated controls.

  • b The day at which tumors treated with both anti-VEGF and IR demonstrated the most pronounced greater than additive growth inhibition.

  • c Obtained by multiplying the fractional tumor volumes obtained by each treatment modality individually to yield the fractional tumor volume expected if the effects of each treatment modality were additive.

  • d Obtained by dividing the observed fractional tumor volume by the expected fractional tumor volume. A ratio <1 indicates a greater than additive effect, and a ratio >1 indicates a less than additive effect. Effects were greater than additive for LLC beginning on day 3; for Seg-1, day 6; for SQ20B, day 12; and for U87, day 3.