Abstract 822P
Background
Olaparib (O) was first poly ADP-ribose polymerase inhibitor (PARPi) approved for use in the UK as maintenance therapy in relapsed BRCA mutated ovarian cancer in 2017. Since then Niraparib (N) and Rucaparib (R) have also been approved as maintenance therapy in patients with relapsed ovarian cancer with and without BRCA gene mutations. Though clinicians now have three drugs to choose from, a lack of head-to-head data means the choice is not a straight forward one. We aim to compare toxicities of the PARPi drugs in order to give clinicians a better idea of which drugs to use in certain scenarios. We report the real world experience of the three PARPi at a UK cancer centre.
Methods
Retrospective data was collected from every patient with a gynaecological cancer who had a PARPi up to the 19th of March 2020. Data lock was the 10th of May 2020.
Results
119 patients with relapsed platinum-sensitive ovarian/fallopian tube or primary peritoneal cancer were included. The group contained 72 patients with BRCA wild-type (wtBRCA), 46 patients with germline mutated BRCA (gBRCA) and one patient with an unknown BRCA status. 71 patients received N, 37 received O and12 patients received R. gBRCA patients were more likely to receive O. wtBRCA patients were more likely to receive N or R. The median number of cycles was 5. The preliminary median PFS for the gBRACA population is 14.9 months. The preliminary median PFS for the wtBRACA population is 7.2 months. Treatment interruption, dose reduction and early stoppage all favoured O. The incidence of grade ≥3 cytopenia was similar across the three drugs. Derangement of liver function, abdominal pain, nausea, vomiting and diarrhoea was observed more often with R. Hypertension, insomnia, mucositis and dyspnoea were seen with more often with N. Evaluation of correlation between BRCA status and incidence of adverse events is ongoing. 41 patients have thus far completed chemotherapy post progression on PARPi. The myelosupressive effects of chemotherapy post-PARPi and its correlations with the individual drugs and BRCA status is being evaluated. Mature data will be presented at the meeting.
Conclusions
Efficacy of PARPi was superior in the gBRCA population compared to wtBRCA. O was the least toxic PARPi.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.