Open-label, randomised Phase III study to evaluate the efficacy and safety of giredestrant compared with fulvestrant, both in combination with a CDK4/6 inhibitor, in patients with ER-positive, HER2-negative advanced breast cancer

Comparison of the effectiveness of the new medicine giredestrant and the standard medicine fulvestrant in the treatment of breast cancer.

PionERA is a study assessing the efficacy and safety of the new hormonal medicine giredestrant in the treatment of advanced hormone receptor-positive, HER2-negative breast cancer.

Purpose of the study

In this study, we compare the new oral medicine giredestrant with standard treatment using fulvestrant, with particular focus on monitoring genetic mutations that may affect response to treatment. We will assess the time to disease progression, survival, treatment safety and the impact on patients’ quality of life.

Study procedure

Patients will be randomly assigned to one of two groups. The first group will receive giredestrant, taken as capsules once daily. The second group will receive fulvestrant, administered as intramuscular injections according to the established treatment schedule. In both groups, treatment will be combined with palbociclib, abemaciclib or ribociclib, according to the physician’s choice.

The duration of participation for an individual patient is approximately 40 months, but it may be shorter or longer, depending on the course of the disease and response to treatment.

Who can take part?

Patients aged 18 years or older with hormone receptor-positive, HER2-negative breast cancer that has progressed despite adjuvant endocrine therapy.

How to apply?

If you are interested in participating or would like to find out more, please speak with your physician at the Institute of Oncology Ljubljana or contact the study staff by email at [email protected].

Participation in the study is entirely voluntary and may be withdrawn at any time without any consequences. Your identity will remain anonymous, and your safety will be ensured.

Participation in the study offers the possibility of access to modern forms of treatment and represents an important contribution to the development of new therapeutic options.