A, percent decrease in PAR levels at 2–8 hours on Day 1 versus veliparib AUC0–9h. Shown is the mean decrease at 2, 4 and 8 hours after veliparib treatment. Values at or below the LLQ were assumed to be at the LLQ. Line shows fit of data to a 3-parameter sigmoidal equation by non-linear regression using SigmaPlot (version 12.0). R2 = 0.25, p = 0.031. B, percent decrease in PAR levels at 0 hours on Day 2 versus veliparib AUC0–9h on Day 1. Samples with values below the LLQ at 0 h on Day 2 were omitted. Line shows fit of data to a 3-parameter sigmoidal equation by non-linear regression using SigmaPlot (version 12.0). R2 = 0.33, p = 0.007. Closed circles, patients receiving once daily dosing; open circles, twice daily dosing. C, relationship between mean decrease in PAR levels at hours 2–8 on Day 1 relative to Day 1 baseline vs. decrease in PAR levels at hours 2–8 on Day 2 relative to Day 2 baseline.Dashed line indicates equal % inhibition on Days 1 and 2.