Abstract 45P
Background
PLD-Trabectedin is currently an option for patients diagnosed with relapsed ovarian cancer (ROC) with a platinum free interval (PFI) of at least 6 months; also, the advent of PARP-i maintenance therapy has revolutionalized the landscape, creating an ever-growing population who progress afterwards and has yet to be addressed when it comes to efficacy and tolerability of CT schemes.
Methods
This study is a multicenter, retrospective analysis aimed at comparing patients receiving PLD-Trabectedin after being treated with PARP-i (cases) with PARP-i naïve patients (controls). Descriptive and survival analyses were performed. Probability of Progression Free Survival (PFS) was estimated using the Kaplan–Meier method and compared with the log-rank test.
Results
Ninety patients were included in our analyses, 31 controls and 59 cases. The populations were compared for categorial variables (Age, Stage at diagnosis, type of surgery at diagnosis, histology) and no statistical difference was found. Median PFS was 11 months (95% IC 10-12) in the control group vs 6 months (95% IC 6-9) in the case group (p value 0.0017), persisting when adjusted for BRCA mutation. Clinical benefit Rate (CBR) was evaluated, with a HR for progression of 2.23 (95% IC 1.19-4.20, p value 0.012) for the case group. We compared hematological toxicity, gastro-intestinal (GI) toxicity, hand-foot syndrome (HFS), fatigue and liver toxicity; no significant disparity was noted except for HFS with a p value of 0.006. The distribution of G3 and G4 toxicities was equally represented.
Conclusions
The MITO39 study showed a statistically significant difference in PFS between patients previously treated with PARP-i and PARP-i naïve patients for PLD-Trabectedin, therefore suggesting that a previous exposure to PARP-i might inhibit the efficacy of the regimen. Regarding tolerability, the comparison did not yield a remarkable disparity. To our knowledge, these is the first data regarding this topic; PARP-is have now been a standard of care for years, resulting in the need to further explore whether the exposure to this target therapy has any impact in later lines.
Legal entity responsible for the study
MITO.
Funding
Has not received any funding.
Disclosure
S. Pignata: Financial Interests, Personal, Advisory Board: Roche, AstraZeneca, MSD, Clovis, GSK, PharmaMar; Financial Interests, Institutional, Funding: Roche, MSD, Pfizer, AstraZeneca. C. Pisano: Financial Interests, Institutional, Advisory Board: GSK, AstraZeneca. C. Zamagni: Financial Interests, Personal and Institutional, Research Grant: Roche, Eisai, Novartis, AstraZeneca, Pfizer, PharmaMar, Tesaro, Pierre Fabbre, Teva, Seagen, Eli Lilly, Celgene, MSD, GSK, Amgen, Daiichi Sankyo; Financial Interests, Personal and Institutional, Advisory Board: QuintikesIMS. G. Valabrega: Financial Interests, Institutional, Advisory Board: AstraZeneca, GSK, MSD, PharmaMar, Clovis, Eisai. All other authors have declared no conflicts of interest.