Phase 1 trial of olaparib and oral cyclophosphamide in BRCA breast cancer, recurrent BRCA ovarian cancer, non-BRCA triple-negative breast cancer, and non-BRCA ovarian cancer

Chee Khoon Lee, Clare Scott, Geoffrey J. Lindeman, Anne Hamilton, Elizabeth Lieschke, Emma Gibbs, Rebecca Asher, Heath Badger, Robin Paterson, Lauren Macnab, Edmond Michael Kwan, Prudence A. Francis, Frances Boyle, Michael Friedlander

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19 Citations (Scopus)


Background: We conducted a Phase 1 study to evaluate safety and activity of olaparib tablets and oral cyclophosphamide. Methods: Patients had metastatic breast cancer (BC) or recurrent high-grade serous ovarian cancer (HGSOC), performance status 0–2, and ≤3 lines of prior therapy. Patients were treated using a dose escalation strategy with cohort expansion once maximal tolerated dose (MTD) was determined. Dose level 1 (DL1): olaparib 300 mg bid, cyclophosphamide 50 mg on days 1, 3, and 5, weekly. DL2: olaparib 300 mg bid, cyclophosphamide 50 mg, days 1–5 weekly. Results: Of 32 patients, 23 had HGSOC (germline BRCA mutation [gBRCAm] 70%) and 9 had BC (gBRCAm 67%). Four were treated at DL1 and 28 at DL2, the MTD. Haematological adverse events (AEs) were most common: grade 3/4 AEs: lymphopenia 75%, anaemia 31%, neutropenia 37%, thrombocytopenia 47%. Two permanently discontinued treatment due to haematological AEs. In BC, no objective response was reported. Unconfirmed objective response was 48% and 64% for all HGSOC and gBRCAm subset, respectively. CA125 responses were 70% (all HGSOC) and 92% (gBRCAm). Conclusions: In HGSOC and BC, olaparib 300 mg bid and cyclophosphamide 50 mg on days 1–5 weekly were tolerable and active, particularly in gBRCAm, and is worthy of further investigation.

Original languageEnglish
Pages (from-to)279-285
Number of pages7
JournalBritish Journal of Cancer
Issue number3
Publication statusPublished - 5 Feb 2019

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