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Breast Cancer Research Trust NZ, gaining knowledge and saving lives

PersevERA trial

A study to compare GDC-9545 plus palbociclib versus letrozole plus palbociclib in people with estrogen receptor-positive, HER2-negative metastatic breast cancer 

Scientific Title

A Phase III randomized, double-blind, placebo-controlled, multicenter study evaluating the efficacy and safety of GDC-9545 combined with palbociclib compared with letrozole combined with palbociclib in patients with estrogen receptor-positive, HER2-negative locally advanced or metastatic breast cancer. Protocol BO41843


Women and men have the hormone estrogen in their body and estrogen can make some breast cancers grow. These are estrogen receptor (ER) positive breast cancers. Treatment for these cancers are either to block the hormone getting to the cancer cells, or to lower the amount of the hormone in the body. These treatments are called hormone therapy. Giredestant is a new hormone therapy drug. It blocks estrogen from getting to the breast cancer cells.

Letrozole is a hormone therapy for women who have gone through the menopause. It works by lowering the level of estrogen in the body. Palbociclib is a targeted drug called a cancer growth blocker. It works by blocking proteins that cancer cells use to grow and divide. Doctors use palbociclib for breast cancer that has spread to the surrounding tissue or to another part of the body. Researchers think that adding giredestrant to palbociclib might work better for people with ER positive breast cancer that has spread.

Ask your Oncologist if this trial is suitable for you.