Astra Zeneca breast cancer study: drug misses target

Compared to standard treatment, the drug was no more effective in slowing the progression of the disease. The result could dampen optimism for the drug.

London. Astra Zeneca's breast cancer pill Camizestrant was no better at delaying disease progression than standard treatment in an advanced study. The British drug manufacturer announced this on Friday.

In the study, camizestrant failed to achieve the goal of delaying tumor recurrence or growth. Patients were examined whose breast cancer had returned or had already spread, but who had not yet received any treatment. Astra Zeneca said the data would be published in due course.

The result could dampen optimism for the drug. The experimental breast cancer drug Giredestrant from the Swiss Roche Group also failed in a similar study at the beginning of the year.

Camizestrant is a hormone therapy. The drug is designed to prevent estrogen from binding to cancer cells and promoting their growth. In a previous study of women whose cancer had returned or spread, camizestrant, along with some other cancer drugs, delayed disease progression by more than six months.

The drug, sold under the brand name Etcamah, is approved in the European Union for this type of breast cancer. Astra Zeneca tested camizestrant in combination with the older cancer drug palbociclib to test its effectiveness in a larger group of patients. On September 4, the drug received approval from the U.S. Food and Drug Administration based on another study in a smaller group of patients.

Astra Zeneca believes annual sales of more than five billion dollars are possible with the drug. Analysts surveyed by Bloomberg currently expect sales of around $2 billion in 2031. Success in the patient group now being examined could have enabled almost $2 billion in additional sales, according to Tonia Kefala Stavridi and John Murphy of Bloomberg Intelligence.