Evaluating the Efficacy and Safety of Fulvestrant Plus DNA Damage Repair Inhibitors After a CDK4/6 Inhibitor

Olaparib tablet 300 mg taken orally twice daily Olaparib 500 mg on Days 1, 15, 29, and every 4 weeks thereafter The treatment will continue till disease progression or unacceptable toxicity or withdrawal of consent or another discontinuation criterion is met.

Fulvestrant 500 mg on Days 1, 15, 29, and every 4 weeks thereafter