Phase I study of olaparib in combination with liposomal doxorubicin in patients with advanced solid tumours.

BACKGROUND

Olaparib, an oral PARP inhibitor, has shown antitumour activity as monotherapy in patients with germline BRCA1/2 (gBRCA)-mutated breast and ovarian cancer. This study evaluated olaparib capsules in combination with liposomal doxorubicin (PLD) in patients with advanced solid tumours (NCT00819221).

METHODS

Patients received 28-day cycles of olaparib, continuously (days 1-28) or intermittently (days 1-7), plus PLD (40 mg m(-2), day 1); seven olaparib dose cohorts (50-400 mg bid) were explored to determine the recommended dose. Assessments included safety, pharmacokinetics, pharmacodynamics and preliminary efficacy (objective response rate (ORR)).

RESULTS

Of 44 patients treated (ovarian, n=28; breast, n=13; other/unknown, n=3), two experienced dose-limiting toxicities (grade 3 stomatitis and fatal pneumonia/pneumonitis (200 mg per 28-day cycle); grade 4 thrombocytopenia (400 mg per 7-day cycle)). The maximum tolerated dose was not reached using continuous olaparib 400 mg bid plus PLD. Grade ≥3 and serious AEs were reported for 27 (61%) and 12 (27%) patients, respectively. No major pharmacokinetic interference was observed between olaparib and PLD. The ORR was 33% (n=14 out of 42; complete response, n=3). A total of 13 responders had ovarian cancer: 10 were platinum-sensitive, 11 had a gBRCA mutation.

CONCLUSIONS

Continuous/intermittent olaparib (up to 400 mg bid) combined with PLD (40 mg m(-2)) was generally tolerated and showed evidence of antitumour activity in ovarian cancer.