Drugmaker AstraZeneca on Wednesday said that its experimental breast cancer treatment 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.

The results showed statistically significant and clinically meaningful improvement in progression-free survival compared with the standard-of-care treatment, the company said.

The British drugmaker claimed study success in a first-line setting in breast cancer. Elsewhere, Rezdiffra sales continued to grow and a cancer biotech cut staff.

In the Phase III SERENA-6 trial, camizestrant—in combination with CDK-inhibitors—beat out current standard-of-care treatments in terms of progression-free survival, according to AstraZeneca.

The phase 3 SERENA-6 study randomised patients with HR-positive, HER2-negative advanced breast cancer whose tumours had an emergent ESR1 mutation to receive either AZ’s candidate or an aromatase inhibitor (anastrozole or letrozole), both taken alongside a CDK4/6 inhibitor (palbociclib, ribociclib or abemaciclib).

Bank of America (NYSE: BAC) analysts estimate a peak sales potential of $6 billion for camizestrant across the SERENA-6 and SERENA-4 trials. They note that SERENA-4 is a first-line (1L) trial requiring success in patients without ESR1 mutations, with data expected in the first half of 2026.

AstraZeneca announced on Wednesday that its drug candidate camizestrant demonstrated a statistically significant and clinically meaningful improvement in progression-free survival in the first-line treatment of hormone receptor-positive,

AstraZeneca Plc’s experimental breast cancer pill helped patients live for longer without their disease worsening, the UK drugmaker said.