1861P - Poly (ADP-Ribose) polymerase inhibitors (PARPI): Associated thrombosis in patients with ovarian cancer

Background

Clinical trials with PARP inhibitors (PARPi) have shown low incidence of venous and arterial thromboembolic disease (VTE/AT), but real-world data is lacking. The aim was to characterise the VTE/AT in ovarian cancer patients treated with PARPi.

Methods

Retrospective, multicenter study by the Spanish Society of Medical Oncology (SEOM). Ovarian cancer patients initiating PARPi from 2015-2022 were included, with minimum 6-month follow-up. Descriptive analysis, impact on survival, and predictors of VTE/AT using multivariate logistic regression were assessed.

Results

329 patients were enrolled, and over an observation period equivalent to 489 person-years, 16 thrombotic events were identified (4.9%; 3.3 events per 100 person-years). The form of presentation was: 31.3% deep vein thrombosis (DVT), 25% pulmonary embolism (PE), 18.8% visceral thrombosis, 12.5% catheter-associated thrombosis, 6.3% other forms of venous thrombosis, and 6.3% mixed event (venous and arterial). Concurrent with the diagnosis of thrombosis, 25% (n=4) were in progression. The median time between start of PARPi and VTE/AT was 4 months (interquartile range: 2–14.3 months). 62.5% of events were incidentally diagnosed and 75% in the outpatient setting. No patient experienced recurrence or bleeding as a complication. A higher proportion of thrombotic events was observed with olaparib (6.3%) compared to niraparib (4%) and rucaparib (0%), but the differences were not statistically significant (p=0.398). The most frequent presentation of VTE/AT associated with olaparib was DVT (40%), while in patients who received niraparib it was PE (50%), without a significant association being observed (p=0.2). Median overall survival was 47 months (95% CI 37.8-56.2) in the subgroup without VTE/AT, while in patients with VTE/AT it was 63 months (95% CI 7.8-18.2) (log-rank test=0.876). Multivariate analysis revealed that combination treatment (PARPi + bevacizumab) was associated with a lower risk of VTE/AT (OR 0.26, 95% CI 0.095-0.72) compared to PARPi alone.

Conclusions

The risk of VTE/AT associated with PARPi in patients with ovarian cancer is low, consistent with that has been described in clinical trials. VTE/AT associated with these drugs did not impact on survival.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

The authors.

Funding

Has not received any funding.

Disclosure

M. Sanchez Canovas: Financial Interests, Personal, Speaker, Consultant, Advisor: Leo Pharma, SANOFI, Angellini, Lundbeck. F.J. Garcia Verdejo: Financial Interests, Speaker, Consultant, Advisor: Rovi, Sanofi, Pfizer. T. Quintanar Verduguez: Financial Interests, Personal, Advisory Board: Pfizer; Financial Interests, Personal, Invited Speaker: MSD Oncology, Daiichi Sankyo, Lilly, Novartis; Financial Interests, Institutional, Local PI, pi clinical trial: AstraZeneca. C. Salvador Coloma: Financial Interests, Personal, Invited Speaker: GSK, Pfizer, MSD. A.I. Ferrer Perez: Financial Interests, Speaker, Consultant, Advisor: GSK, Bristol Myers Squibb, Roche, AstraZeneca. F.J. Teigell Muñoz: Financial Interests, Personal, Speaker, Consultant, Advisor: Abbott, Daiichi Sankyo, Chiesi, Techdow Pharma. A.J. Munoz Martin: Financial Interests, Personal, Advisory Board: GSK, AstraZeneca, Sanofi, Celgene, Servier, MSD, Pfizer, Leo Pharma, Roche; Financial Interests, Personal, Invited Speaker: Lilly, Rovi, STADA, Menarini, BMS; Financial Interests, Institutional, Advisory Board, VTE risk assessment model: Genincode; Financial Interests, Institutional, Local PI: Celgene. All other authors have declared no conflicts of interest.