Abstract P5-11-19: Ribociclib for the treatment of hormone receptor-positive refractory advanced breast cancer: Managed access programme in Turkey
Authors: Demirci Umut , Gokmen Erhan , Eralp Yesim , Gunduz Seyda , Goksu Sema Sezgin , Korkmaz Taner , Kostek Osman , Turhal Serdar , Paydas Semra , Topcu Sevgi , Cakar Burcu , Karabulut Bulent , Tanrıverdi Ozgur , Karaca Burcak , Deniz Gulhan Ipek , Alan Ozkan , Turkoz Fatma Paksoy , Basaran Gul 
Published: March 2020

Background: Ribociclib combined with endocrine therapy (ET) have demonstrated efficacy in patients with hormone receptor (HR) positive advanced breast cancer (ABC) who experienced progression during prior ET. However, there are scarce data chemo-endocrine refractory patients with ribociclib. We analyzed the efficiency and safety of ribociclib from the real world evidence in this heavily treated group of patients in Managed Access Programme (MAP).

Methods: MAP launched in Turkey, between October 2017 and March 2018. We retrospectively analyzed survival outcomes and toxicities of 52 patients from this programme.

Results: The median age of the total population was 54.5 years (28-76 years) and 71.2% (n=37) of the patients were postmenapousal. Median estrogen receptor and progesterone receptor positivity were 90% (15-100) and 25% (0-100), respectively. Median Ki67 was 25% (3-90%). 46.2% and 73.1% of the patients had adjuvant chemotherapy and ET, respectively. Denovo metastatic disease was detected 28.8% of the patients. Visceral disease (lung, liver, and others) was present in 21 patients (40.3%), and 16 (30.8%) had bone-only disease.

Median treatment line of ABC before ribociclib was 4 (1-9). ET was performed 36.5% and 38.4% for the first and second line treatment of ABC, respectively. Most of the patients (71.5%) treated anthracycline and taxanes before ribociclib. Ribociclib combined with ET in the majority of the patients; aromatase inhibitors (51.9%), fulvestrant (26.9%) and tamoxifen (3.8%). However, 4 patients were receiving ribociclib monotherapy. As of May 21, 2019, 26.9% (n=14) of patients were still receiving treatment.

Objective response rate was 38.4% (n=20) and additional 18 (34.6%) stable diseases were detected. Median progression free survival and overall survival were 5 months (3.9-6.1 months) and 15.2 months (13.7-16.8 months), respectively. While 48.1% of the patients treated with chemotherapy after ribociclib failure, only two patients treated with ET after ribociclib failure.

Ribociclib was generally well tolerated all the study population, grade 2 emesis was developed only two patients. Grade 3/4 neutropenia was developed in 36.5% of the patients. There was no febrile neutropenia. Urosepsis (n=1) and grade 4 thrombocytopenia (n=1) were developed in seperate patients. A prolongation of QTcF from baseline occurred in two patients. Dose reductions occurred in 21.2% (n=11) of the patients. There was 3 deaths during treatment.

Conclusions: Ribociclib is an effective agent with tolerable safety profile even in the heavily pretreated patients with HR positive ABC especially combined with ET.

Citation Format: Umut Demirci, Erhan Gokmen, Yesim Eralp, Seyda Gunduz, Sema Sezgin Goksu, Taner Korkmaz, Osman Kostek, Serdar Turhal, Semra Paydas, Sevgi Topcu, Burcu Cakar, Bulent Karabulut, Ozgur Tanrıverdi, Burcak Karaca, Gulhan Ipek Deniz, Ozkan Alan, Fatma Paksoy Turkoz, Gul Basaran. Ribociclib for the treatment of hormone receptor-positive refractory advanced breast cancer: Managed access programme in Turkey [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 P5-11-19.