What next option available if CDK4/6 get failed

[Deepak1965]

Hi all and Dr. Sumeet Shah

one of my relative diagnosed with oligometastatic left breast cancer in 2015 treated with chemo (4 Cycle 5FEC and 1 Cycle of Docetaxel) than surgery (lumpectomy) again 2 cycle of 5FEC chemo 2016 march NED put on tamoxifen 20 mg regular check up and in 2021 it relapsed in operated breast spread to right axillary, mediastinal, iliac bone and liver again start with zoledronic acid 4mg letrozole with targeted therapy CDK4/6 palbace 100mg and palliative radiation given 16 cycle till august 2022 it works very well than pain start in stomach than we do pet scan to find reason of pain which says disease was clear from all other part and progressed in liver again done biopsy to confirm whether its malignant or not comes positive er + PR negative and HER2 negative with 1+ so change medicine palbace 100 mg with fulvestrant 500 mg no response in 2 month and disease in progress in liver So, wants to know what is the next line of treatment we can give?

There is option 1 put on weekly chemo. i wants to know what is the new therapy we can do, We can not use alpelisib as it can shoot sugar level as she is already diagnosed with diabetics So what is the next line of treatment