outcomes of first-line olaparib mono-maintenance therapy-a multicenter, retrospective study using data from real-world clinical setting

Conditions: Ovarian Neoplasms

Summary: four phase iii trials in ovarian cancer consistently showed that front-line poly(adp-ribose) polymerase (parp) inhibition can significantly improve progression-free survival. based on these findings, current clinical guidelines recommend the olaparib + bevacizumab combination as a maintenance therapy for ovarian cancer patients with brca1/2 wild-type or unknown mutation status who have a complete response (cr)/ partial response (pr) after completing bevacizumab-containing first-line therapy. however, bevacizumab is not a national medical products adminstration（nmpa）-approved agent for ovarian cancer patients. in this setting, olaparib mono-maintenance therapy has been implemented among patients with brca-wild type tumors in clinical practice in china.

the main objective is to evaluate the outcome of olaparib-based maintenance therapy by proportion of patients alive and progression free at 1 year (1-yr pfs rate) we hypothesize that olaparib monotherapy could be beneficial for tbrcawt high-grade serous ovarian cancer (hgsoc) patients who are treated with platinum-based first-line chemotherapy. the secondary objectives are to evaluate the outcomes of olaparib-based maintenance therapy by: 1) 2-yr pfs rate; 2) median pfs; 3) median time to first subsequent therapy or death (mtfst) ; 4) post-progression treatment after first progression; 5) reason for olaparib dose adjustment, dose interruptions, and dose discontinuations; 6) reason for use of concomitant therapy. the exploratory objective is to evaluate the status quo of genetic testing, r0 resection and related outcomes.

Eligibility criteria:
inclusion criteria: patients are eligible to be included in the study only if they met all the following criteria: * female patients must be ≥18 years old at diagnosis. * patients with newly diagnosed, histologically confirmed, advanced (figo stage iii-iv) ovarian cancer, primary peritoneal cancer and / or fallopian-tube cancer and received olaparib from aug 2018 up to dec 2020 (the time range could be extended in order to recruit enough eligible subjects as required). * patients must have a tumor brca testing result which is tbrcawt, defined as tumor brca wild type (patients without evidence of brca 1 and/or brca 2 deleterious or suspected deleterious mutations). * patients who have completed first-line platinum-based chemotherapy and were in clinical complete response (cr) or in partial response (pr). * patients who were still in cr or pr before receiving maintenance therapy. * patients who received at least one dose of olaparib tablets monotherapy as maintenance therapy within three months after platinum-based chemotherapy and without disease progression. exclusion criteria: patients are excluded if any of the following factors were present: * patient with multiple primary cancers as reported in emr. * concomitant any anti- cancer therapy (chemotherapy, immunotherapy, hormonal therapy (hormone replacement therapy (hrt) is acceptable), radiotherapy, biological therapy or other novel agent) during olaparib maintenance. * any previous treatment with parp inhibitor. * patients with myelodysplastic syndrome/acute myeloid leukaemia or with features suggestive of mds/aml. * patients with symptomatic uncontrolled brain metastases. * any other concerns related to decreased efficacy and safety of maintenance therapy.

Keywords: tbrca， olaparib