TABLE 2.
Comparison of antiviral potencies of VX-497 and ribavirin
| Virusa | Ribavirin
|
VX-497
|
Fold increased potency of VX-497b | ||
|---|---|---|---|---|---|
| IC50 (μM) | Therapeutic indexc | IC50 (μM) | Therapeutic index | ||
| HBV | 43.8 | 2.2 | 0.4 | 13.7 | 110 |
| HCMV | 148.5 | >3.4 | 0.8 | 38.8 | 186 |
| RSV | 20.9 | 24.0 | 1.1 | 9.0 | 19 |
| HSV-1 | 162 | >3.1 | 6.3 | >4.9 | 25.7 |
| Parainfluenza-3 virus | 197.9 | 2.5 | 13.8 | >2.2 | 14.4 |
| BVDV | 44.6 | 11.2 | 12.4 | 2.5 | 3.6 |
| VEEV | >500 | <1 | 19.2 | 1.6 | >26 |
| EMCV | 17.0 | >29.4 | 1.0 | 20.0 | 17 |
a
The assays with the viruses are described in the footnotes to Table 1.
b
Fold increase in potency of VX-497 = IC50 of ribavirin divided by the IC50 of VX-497.
c
Therapeutic index = cytotoxicity measurement (CC50, highest concentration of drug with no cytotoxicity, or minimum toxic concentration) divided by the IC50.