Final report of a phase I study of veliparib (ABT-888) in combination with low-dose fractionated whole abdominal radiation therapy (LDFWAR) in patients with advanced solid malignancies and peritoneal carcinomatosis with a dose escalation in ovarian and fallopian tube cancers.

2584Background: Combining low-dose radiation therapy with poly (ADP-ribose) polymerase (PARP) inhibition has been shown to enhance anti-tumor efficacy through potentiating DNA damage in tumor cells. We combined low dose fractionated whole abdominal radiation (LDFWAR) with escalating doses of veliparib (ABT-888), an orally available, small molecule PARP inhibitor, in patients (pts) with peritoneal carcinomatosis from advanced solid tumor malignancies with a dose escalation in ovarian and fallopian cancer patients (OV). Methods: Pts were treated with escalating doses of veliparib, 40-400mg PO BID on days on days 1-21 of 3 28-day cycles on 6 dose levels. LDFWAR consisted of 21.6Gy in 36 fractions, 0.6 Gy twice daily on days 1 and 5 for weeks 1-3 of each cycle. Circulating tumor cells (CTCs) were serially collected. Quality of life (QoL) was assessed using the EORTC-QLQ-C30 questionnaire. Results: 32 pts were treated. Median follow-up was 45 months (10-50). The most common treatment-related gr3 and 4 toxiciti...