Camizestrant improves breast cancer survival in key trial

Drugmaker AstraZeneca on Wednesday said that its experimental breast cancer treatment Camizestrant improved patient survival without the disease getting worse in a study, a positive outcome in the development of the therapy key to the company’s pipeline.

Camizestrant, in combination with a standard of care agent designed to suppress proteins that spur tumour growth, showed improvement in the main goal of progression-free survival when given as a first-line treatment, the company said in an interim analysis of the trial that will continue as planned.

“This critical read-out moves us one step closer to realising the potential of camizestrant to become a new standard-of-care,” AstraZeneca executive Susan Galbraith said.

The company’s pipeline has evolved significantly in recent years to keep up with demand, with newer cancer therapies making up a rising proportion of its plans for its roster of medicines.

The trial update was a “material positive surprise” for AstraZeneca, which has indicated that camizestrant could generate peak sales of more than $5 billion following approvals, Barclays analysts said in a note.

“Whilst we do think there was an expectation that this would be the first of (the company’s) three major readouts of the year … we’d been thinking this readout would be coming in the middle of the summer.”

The trial is evaluating the camizestrant combination for treating an advanced form of breast cancer where patients have a type of protein on cancer cells that makes them susceptible to tumour growth when the cells are stimulated by certain hormones.

The patients also had low levels of another type of protein responsible for cell growth and typical of many breast cancers, HER-2. They later presented with a mutation of the estrogen-coding ESR1 gene, which can trigger cancer growth.

The trial used residual DNA from cancer cells that can find its way into a patient’s bloodstream to identify when patients were beginning to resist the standard endocrine treatment, and were switched to the camizestrant combination after an ESR1 mutation was detected.