Innovation of the 1st line strategy optimized as abemaciclib with endocrine therapy based on the ESR1 mutation of ctDNA for HR-positive HER2-negative advanced metastatic breast cancer patients - Multi-institutional phase 2 trial
To explore the efficacy of a treatment strategy to select an endocrine agent based on assessment of ESR1 mutation status by ctDNA analysis in patients who continue abemaciclib and aromatase inhibitor combination therapy for at least 6 months as first-line treatment for hormone receptor (HR)-positive, HER2-negative advanced metastatic breast cancer.
Hormone receptor-positive, HER2-negative inoperable or recurrent breast cancer
2-year PFS rate from the secondary enrollment (all arms)
- Trial Period
- Lead Principal Investigator
Tetsuhiro Yoshinami, MD, PhD.
Department of Breast and Endocrine Surgery, Osaka University Hospital
- Target Sample Size
Secondary enrollment: 150 patients
Repeated "ctDNA measurements" will be performed for the eligible patients treated with Aromatase inhibitor + abemaciclib combination therapy (AI + ABE) as first-line treatment.
In case of ESR1 mutation detected by "ctDNA measurement", treatment would change.
Protocol treatment overview
1) AI + ABE continued for 3 months after primary registration
2) If no sign of PD is seen on the images after 3 months from the primary registration, secondary registration will be performed.
3) After secondary registration, treatment will be decided based on ESR1 mutation status of ctDNA measurement.
・ ctDNA evaluation period: before secondary registration, 24 weeks, 48 weeks after secondary registration
・In case of ESR1 mutation detected at any point, AI + ABE change to fulvestrant (FUL) + ABE.
・ In case of no ESR1 mutation detected at either point, AI + ABE will be continued.
4) ctDNA measurement will be performed at 24 weeks after start of FUL + ABE.
・In case of ESR1 mutation detected at this point, FUL + ABE will be continued
・In case of no ESR1 mutation detected at this point, FUL will be stopped and AI + ABE will be resumed.
- Source of Funding
Eli Lilly Japan K.K.
- Conference Presentation
- Articles and Publications
- COI Disclosure