Table 1. Comparison of the free intracellular pralatrexate and MTX levels.
Extracellular concentration | 0.05 M | 0.5 M | ||
---|---|---|---|---|
pralatrexate | MTX | pralatrexate | MTX | |
Total drug (μM) | 0.49 ± 0.07 | 0.39 ± 0.04 | 1.25 ± 0.10 | 1.04 ± 0.08 |
DHFR-bound (μM) | 0.31 ± 0.05 | 0.33 ± 0.04 | 0.44 ± 0.02 | 0.59 ± 0.06 |
Free intracellular drug (μM) | 0.17 ± 0.08 | 0.05 ± 0.04* | 0.81 ± 0.12 | 0.45 ± 0.10** |
Free intracellular/extracellular drug | 3.4 | 1 | 1.6 | 0.9 |
P-value of 0.04,
P-value of 0.01, for the difference between pralatrexate and MTX.