PGP and neoplasm: In vivo, IPI549 improved the anti-tumor efficacy of paclitaxel in tumor xenograft model of P-gp-overexpressing SW620/Ad300 colon cancer with a ratio of growth inhibition for tumor volume (IRV) = 74% and for tumor weight (IRW) = 72%, compared to 42% IRV and 37% IRW for the paclitaxel alone treatment (De Vera et al., 2019).