A combination of the company’s breast cancer drug Etcamah did not delay worsening of the disease enough to meet the SERENA-4 late-stage trial’s main goal, AstraZeneca said.

  • AstraZeneca, however, said progression-free survival improved numerically. 
  • Etcamah is a once-daily pill that breaks down the estrogen receptor many breast cancers use to grow and is already approved for a narrower group of breast cancer patients. 
  • The setback lands on a pipeline already under scrutiny.

Shares of AstraZeneca traded 3% lower in after-hours trading on Friday after the drugmaker said a large late-stage breast cancer study of Etcamah missed its main goal, denting hopes of a broader first-line use for one of its most closely watched oncology assets.

What The Trial Showed

The trial SERENA-4 tested Etcamah plus palbociclib against a standard hormone-blocking pill plus palbociclib in 1,371 people starting treatment for advanced hormone-sensitive breast cancer that is not HER2-driven. The Etcamah combination did not delay disease progression enough to meet the trial’s main goal, though AstraZeneca said there was a numerical improvement. Side effects were in line with what is already known for both drugs. The company said it will present full results later.

Etcamah is a once-daily pill that breaks down the estrogen receptor many breast cancers use to grow. It is already approved in the United States, Europe, Japan and other markets for a narrower group: patients whose tumors pick up a common resistance mutation called ESR1 while they are on first-line hormone therapy. That use is based on an earlier SERENA-6 trial.

Friday’s miss undercuts the case for giving the drug to all newly diagnosed advanced patients from the start, before that mutation appears.

Another Hit After A Rough Year

The setback lands on a pipeline already under scrutiny. In July, AstraZeneca’s heart drug Wainua failed a major heart-disease trial, triggering a steep one-day drop. Rare-disease medicine Ultomiris also missed a rare-disease study. In August, AstraZeneca halted a late-stage lung cancer trial of volrustomig after an independent committee said it was unlikely to beat standard immunotherapy.

Those blows have helped drag the stock down about 20% over six months even as core cancer sales remain a pillar of the business.

Oncology accounts for a large share of AstraZeneca’s growth. Without a broad first-line label in advanced disease, Etcamah’s near-term commercial reach is smaller. Oncology research chief Susan Galbraith called SERENA-4 disappointing but said the company remains confident in the drug’s longer-term potential in early breast cancer.

Two separate large trials, CAMBRIA-1 and CAMBRIA-2, are testing Etcamah after surgery in about 10,000 patients to see if it can cut the risk of recurrence.

How Did AZN Retail Traders React?

On Stocktwits, retail sentiment around AZN stock stayed in ‘bearish’ territory over the past 24 hours, while message volume was ‘high.’

AZN stock has fallen 9% year-to-date. 

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