Background: PARP inhibitors and anti-angiogenics are clinically active in recurrent ovarian cancer (OvCa). Pre-clinical studies suggest these agents can synergize; a phase 2 study demonstrated that combination cediranib/capsule olaparib (C/O) increased progression-free survival (PFS) and response rate (RR) compared to olaparib alone. Olaparib clinical development will proceed using the tablet formulation; we therefore investigated the toxicities and recommended phase 2 dosing (RP2D) of C/O with olaparib tablets. Methods: Cediranib (C) once daily and olaparib (O) twice daily were administered orally in cohorts of 3 patients in a standard 3+3 Phase 1 design. Eligibility included pts with recurrent ovarian cancer. Pts had measurable disease by RECIST 1.1 or met GCIG CA125 criteria. No prior anti-angiogenics in the recurrent setting or prior PARP inhibitor were allowed. Results: 24 pts have been treated since May 2014 at 6 dose levels (C 20mg QD/O 200mg BID (3 pts); C 20mg QD/O 250mg BID (3); C 20mg QD/O 300mg BID (6); C 30mg QD/O 150mg BID (3); C 30mg QD/O 200mg BID (6); C 30mg QD/O 250mg BID). One DLT (gr 3 rotator cuff injury) occurred at the 30/200 dose level and two DLTs (1 > 7d hold for proteinuria; 1 gr 4 HTN and gr 2 intracranial hemorrhage) at the 30/250 dose level. Other related gr 3/4 adverse events (AEs) included HTN (5), vomiting (1), fatigue (1), myalgia (1), and thromboembolic event (1). Most common AEs included nausea (79%), fatigue (75%), diarrhea (58%), vomiting (42%), and HTN (42%). The RP2D levels are C 30mg QD/O 200mg BID and C 20mg QD/O 300mg BID. Best response in 21 evaluable OvCa pts (13 plat-resistant; 8 plat-sensitive) include 2 CR, 4 PR, 14 SD, 1 PD, including 1 CR, 2 PR and 2 SD in 5 evaluable pts at the 30/200 and 1 CR and 4 SD in 5 pts at the 20/300 dosing levels. Conclusions: RP2D for combination C/O tablets is cediranib 30mg/olaparib 200mg BID or cediranib 20mg/olaparib 300mg BID. Observed toxicities are consistent with those seen with combination using olaparib capsules. Preliminary assessment of activity demonstrated a 29% unconfirmed response rate in OvCa pts using a regimen that is safe and tolerable. An expansion cohort will enroll at the cediranib 30mg/olaparib 200mg BID level. Clinical trial information: NCT01116648