A Phase Ib/II Study Confirmed Inhibition of Autophagy Synergizes Anti-tumor Effect of High Dose CDK4/6i

This study is testing whether combining high-dose CDK4/6 inhibitor therapy with a drug that blocks a cellular recycling process (autophagy) can improve outcomes in people with advanced solid tumors — including breast cancer and liposarcoma — whose cancer has progressed on standard CDK4/6 inhibitor treatment. **You may be eligible if...** - You are 18 or older with confirmed advanced or metastatic solid tumors (including breast cancer or liposarcoma) - Your cancer has previously been treated with CDK4/6 inhibitors and stopped responding - You have at least one measurable tumor on imaging - Your overall health (ECOG 0-2) and organ function are adequate **You may NOT be eligible if...** - You have had major surgery within 4 weeks before starting treatment - You have had prior treatment with two or more CDK4/6 inhibitors for advanced disease - You have symptomatic brain or spinal fluid spread of cancer - You are pregnant or breastfeeding - You are HIV positive, have active hepatitis B, or positive hepatitis C antibodies - You have a retinal vascular disease that makes the study drug hydroxychloroquine unsafe - You have serious cardiovascular disease Talk to your doctor to see if this trial is right for you.