Real-world clinical data analysis of PARPi as first-line maintenance therapy in newly diagnosed epithelial ovarian cancer patients

Abstract

Objective: The real-world clinical data of patients with newly diagnosed ovarian cancer (including fallopian tube cancer and primary peritoneal cancer) who received first-line maintenance therapy with poly adenosine diphosphate ribose polymerase inhibitor (PARPi) were retrospectively analyzed, and the prognostic factors were preliminarily explored. Methods: (1) The clinicopathological data and follow-up data of ovarian cancer patients treated with PARPi first-line maintenance therapy from August 2018 (PARPi was launched in China) to December 31, 2021 in Sichuan Cancer Hospital were collected (real-world clinical data). (2) According to the different types of PARPi, real-world clinical data were divided into olaparib group and niraparib group, which were respectively compared with the inclusion and exclusion criteria of representative domestic and foreign phase Ⅲ randomized controlled trials (RCT), including olaparib as first-line maintenance therapy for advanced ovarian cancer patients with BRCA1/2 gene mutation (SOLO-1 study), niraparib as first-line maintenance therapy (PRIMA study), and niraparib as first-line maintenance therapy for Chinese advanced ovarian cancer patients (PRIME study). (3) The prognosis of the two groups and the prognostic factors were analyzed. Results: (1) A total of 83 patients were included in this study, with a median age of 51 years (47-57 years), including 75 cases of ovarian cancer, 5 cases of fallopian tube cancer, and 3 cases of primary peritoneal cancer; 5 cases of stage Ⅰ, 9 cases of stage Ⅱ, 55 cases of stage Ⅲ, 12 cases of stage Ⅳ, and 2 cases of unknown stage; neoadjuvant chemotherapy (NACT) was performed in 40 cases and non-NACT in 43 cases; 62 cases had no visible residual lesion after surgery (R0), 9 cases had residual disease lesions <1 cm (R1), 8 cases had residual disease lesions ≥1 cm (R2), and 4 cases with unknown postoperative residual disease. Thirty-two cases had PARPi treatment interruption, 40 cases had PARPi reduction, and 1 case terminated treatment due to acute leukemia. Of the 83 patients, 35 were in the olaparib group and 48 were in the niraparib group. The proportion of patients with high-grade serous carcinoma (100% and 75%, respectively) and the proportion of BRCA mutant patients (91% and 10%, respectively) in the olaparib group were higher than those in the niraparib group (all P<0.01). (2) Compared with the inclusion and exclusion criteria of the SOLO-1 study, the olaparib group had only 60% (21/35) coincidence rate; compared with the inclusion and exclusion criteria of PRIMA and PRIME studies, the coincidence rates of niraparib group were only 31% (15/48) and 69% (33/48). The most common reasons for non-compliance were number of chemotherapy courses, histopathological type, and surgical pathological stage. (3) Of the 83 cases received first-line maintenance therapy with PARPi, the median follow-up was 15.9 months (11.3-22.9 months), the median progression-free survival (PFS) was 29.7 months (95%CI: 25.9-33.6 months), and the median overall survival was 49.8 months (95%CI: 47.4-52.2 months). Univariate analysis showed that unilateral or bilateral ovarian cancer, efficacy after platinum-containing chemotherapy, presence or absence of measurable lesions at the end of chemotherapy, and total number of chemotherapy courses were significantly associated with PFS (all P<0.05). Multivariate analysis showed that unilateral or bilateral ovarian cancer, total number of chemotherapy courses, and efficacy after platinum-containing chemotherapy were independent factors affecting PFS in stage Ⅱ-Ⅳ patients with PARPi first-line maintenance therapy (all P<0.05). Conclusions: Unilateral ovarian cancer, the total number of chemotherapy courses no more than 9, and achieving complete response after platinum-containing chemotherapy before maintenance therapy are independent influencing factors of PFS benefit in patients with PARPi first-line maintenance therapy. Due to the large differences between the patients in real clinical practice and the research subjects of phase Ⅲ RCT, the results of representative retrospective studies still have important clinical reference significance.