Abstract
Response to subsequent platinum-based chemotherapy post PARP inhibitor in recurrent epithelial ovarian cancer.
Author
person
Genevieve MacAulay Vacheresse
University of Ottawa, Ottawa, ON, Canada
info_outline
Genevieve MacAulay Vacheresse, Elham Sabri, Sheryl Domingo, Tien Le
Full text
Authors
person
Genevieve MacAulay Vacheresse
University of Ottawa, Ottawa, ON, Canada
info_outline
Genevieve MacAulay Vacheresse, Elham Sabri, Sheryl Domingo, Tien Le
Organizations
University of Ottawa, Ottawa, ON, Canada, OHRI, Ottawa, ON, Canada, The Ottawa Hospital, Ottawa, ON, Canada
Abstract Disclosures
Research Funding
Other
University of Ottawa Department of Obstetrics & Gynecology
Background:
Maintenance therapy with PARP inhibitors (PARPi) can increase progression free survival (PFS) for recurrent or metastatic platinum-sensitive epithelial ovarian cancer (EOC). Little is known about disease trajectory following treatment with these agents, though some evidence suggests a decreased response to subsequent platinum-based chemotherapy. This retrospective cohort study assessed real-world response rates to platinum-based chemotherapy for recurrent high grade EOC following treatment with a PARPi.
Methods:
All patients prescribed a PARPi as maintenance therapy for recurrent or metastatic EOC at the Ottawa Regional Cancer Center (ORCC) from September 2017 to May 2022 were included. PFS following penultimate therapy (line of therapy preceding PARPi initiation) as well as the PFS following subsequent platinum-based chemotherapy in patients with disease progression more than 6 months after penultimate therapy were calculated. Incidence of platinum resistance in patients with disease progression following PARPi therapy was determined.
Results:
91 patients were included in the analysis including 54 patients on niraparib and 36 patients on olaparib. Follow-up after initiation of PARPi ranged from 4.6 months to 62.0 months with a median of 16.3 months. 54 (59.3%) of patients experienced disease progression after initiation of PARPi therapy, including 10 (11.0%) who progressed within 6 months of their penultimate therapy. Of the 44 patients who experienced disease progression more than 6 months following penultimate therapy, 32 (72.7%) were rechallenged with platinum-based chemotherapy. Of these, 16 (50.0%) experienced further disease progression with 14 (43.8%) progressing within 6 months of their platinum rechallenge. Median PFS following platinum rechallenge was 4.4 months (from 0.8 months to 34.9 months), significantly lower than previous reports.
Conclusions:
Patients who experienced disease progression following PARPi therapy showed a poor response to subsequent platinum-based chemotherapy, even when progression occurred more than 6 months after completion of their penultimate platinum-based chemotherapy. This supports the theory that PARPi resistance may be a surrogate for platinum resistance and raises concern for possible contribution of PARPi in the induction of platinum resistance in recurrent EOC.
4 organizations
3 drugs
1 target
Organization
University of OttawaOrganization
Ottawa, ON, CanadaOrganization
OHRIOrganization
The Ottawa Hospital Research InstituteDrug
PARP inhibitorsDrug
niraparibDrug
olaparibTarget
PARP