PAPPA and ovarian cancer: They then examined these models with ultrasound after 28 days of treatment and found that carboplatin/paclitaxel combined with mAb-PA induced tumor degeneration below baseline in one high PAPP-A PDX model and inhibited tumor growth in another three models compared with carboplatin/paclitaxel + IgG2a, while no low PAPP-A PDX models regressed tumor below baseline, suggesting that mAb-PA sensitized ovarian cancer to carboplatin/paclitaxel chemotherapy.