Abstract P2-12-09: Randomized study to determine the efficacy of Olanzapine for the prevention of chemotherapy-induced nausea and vomiting (CINV) in Chinese breast cancer patients (PTS)

Background: Adjuvant chemotherapy improves outcomes of pts with early breast cancer, but CINV have been regarded as two of the most disturbing side effects, affecting their quality of life (QoL). In this study, the primary objective was to compare the efficacy of olanzapine in addition to the standard aprepitant-based antiemetic regimen for CINV in pts receiving the 1st cycle of adjuvant AC chemotherapy (adriamycin 60mg/m2 and cyclophosphamide 600mg/m2). The secondary objective was to compare the tolerability and efficacy of such regimen in the 4 cycles of AC. Methods: This is a prospective single center, randomized study. Eligible pts had early stage breast cancer of Chinese ethnicity; they were chemotherapy- naive and treated with adjuvant AC chemotherapy. Antiemetic regimen for all studied population included aprepitant, ondansetron and dexamethasone; patients were randomly allocated to Olanzapine (with olanzapine) or Standard (without olanzapine) arms. Individual patient filled in self-reported diary and visual analogue scale for nausea from which information on nausea, vomiting and use of rescue medication were collected; outcomes were compared during acute phase (0-24 hrs), delay (24-120 hrs) and overall time-frame (0-120 hrs) from initiation of AC. QoL was assessed by Functional Living Index-Emesis (FLIE). Results: 120 pts were randomized. For CINV in Cycle 1 AC, outcomes of Olanzapine vs Standard arms were: complete response (acute phase 70.0 vs 51.7%, p=0.0397; delay phase 75.0 vs 45.0%, p=0.0008; overall time-frame 65.0 vs 38.3%, p=0.0035), complete protection (acute phase 70.0 vs 50.0%, p=0.0253; delay phase 71.7 vs 40.0%, p=0.0005; overall 61.7 vs 36.7%, p=0.0062), total control (acute phase 65.0 vs 41.7%, p=0.0104; delay phase 60.0 vs 31.7%, p=0.0018; overall 51.7 vs 26.7%, p=0.0050), ‘no vomiting’ (acute phase 73.3 vs 51.7%, p=0.0142; delay phase 76.7 vs 48.3%, p=0.0013; overall 68.3 vs 40.0%, p=0.0018), ‘no significant nausea’ (acute phase 95.0 vs 75.0%, p=0.0017; delay phase 91.7 vs 65.0%, p=0.0004; overall 91.7 vs 63.3%, p=0.0002),‘no nausea’ (acute phase 76.7 vs 53.3%, p=0.0074; delay phase 65.0 vs 35.0%, p=0.0010; overall 58.3 vs 33.3%, p=0.0060), and need of rescue medication (acute phase 3.3 vs 11.7%, p=0.0654; delay phase 6.7 vs 21.7%, p=0.0133; overall 8.3 vs 23.3%, p=0.0244). Assessment of FLIE on Day 6 after Cycle 1 AC between the Olanzapine vs Standard arms revealed better QOL mean scores for nausea domain (p Conclusions: In this prospective study of Chinese women with breast cancer, the addition of olanzapine to standard antiemetic regimen increases the control of CINV and improves the QoL of pts during AC chemotherapy. Funding: Madam Diana Hon Fun Kong Donation for Cancer Research. Citation Format: Winnie Yeo, Thomas KH Lau, Vicky TC Chan, Li Leung, Dong Lai, Elizabeth Pang, Maggie Cheung, Ashley Wong, Winnie MT Soo, Vanessa TY Yeung, Teresa Tse, Eva WM Yeung, Daisy CM Lam, Kenneth CW Wong, David R Johnson, Kim PK Ng, Herbert Loong, Joyce TY Ng, Florence Mok, Mimi KM Lee, Darren MC Poon, Yvonne SH Yau, Macy Tong, Joyce JS Suen, Frankie KF Mo. Randomized study to determine the efficacy of Olanzapine for the prevention of chemotherapy-induced nausea and vomiting (CINV) in Chinese breast cancer patients (PTS) [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P2-12-09.