A Phase 1 trial of the poly(ADP-ribose) polymerase inhibitor olaparib (AZD2281) in combination with the anti-angiogenic cediranib (AZD2171) in recurrent epithelial ovarian or triple-negative breast cancer

Blogger's Note: does not indicate if patients had BRCA mutation/s (eg. can assume high % were serous ovarian)

Abstract

Background

Poly(ADP-ribose) polymerase (PARP)-inhibitors and anti-angiogenics have activity in recurrent ovarian and breast cancer; however, the effect of combined therapy against PARP and angiogenesis in this population has not been reported. We investigated the toxicities and recommended phase 2 dosing (RP2D) of the combination of cediranib, a multitargeted inhibitor of vascular endothelial growth factor receptor (VEGFR)-1/2/3 and olaparib, a PARP-inhibitor (NCT01116648).

Methods

Cediranib tablets once daily and olaparib capsules twice daily were administered orally in a standard 3+3 dose escalation design. Patients with recurrent ovarian or metastatic triple-negative breast cancer were eligible. Patients had measurable disease by Response Evaluation Criteria in Solid Tumors (RECIST) 1.1 or met Gynecologic Cancer InterGroup (GCIG) CA125 criteria. No prior PARP-inhibitors or anti-angiogenics in the recurrent setting were allowed.

Results

28 patients (20 ovarian, 8 breast) enrolled to 4 dose levels. 2 dose limiting toxicities (DLTs) (1 grade 4 neutropenia 4days; 1 grade 4 thrombocytopenia) occurred at the highest dose level (cediranib 30mg daily; olaparib 400mg twice daily [BID]). The RP2D was cediranib 30mg daily and olaparib 200mg BID. Grade 3 or higher toxicities occurred in 75% of patients, and included grade 3 hypertension (25%) and grade 3 fatigue (18%). One grade 3 bowel obstruction occurred. The overall response rate (ORR) in the 18 RECIST-evaluable ovarian cancer patients was 44%, with a clinical benefit rate (ORR plus stable disease (SD) >24weeks) of 61%. None of the seven evaluable breast cancer patients achieved clinical response; two patients had stable disease for >24weeks.

Interpretation

The combination of cediranib and olaparib has haematologic DLTs and anticipated class toxicities, with promising evidence of activity in ovarian cancer patients.