Wyeth has lost its legal battle with a woman who claimed that the firm’s hormone-replacement therapy Prempro was responsible for her breast cancer.

A jury at the Philadelphia, which also claimed that the drugmaker acted with malice or reckless disregard, will start to decide on possible punitive damages but has already awarded $1 million in compensatory damages to plaintiff Mary Daniel and $500,000 to her husband.

The 60-year-old woman developed breast cancer after taking the Prempro (conjugated estrogens/medroxyprogesterone acetate) every other day for about 16 months to relieve hot flashes. She had two surgeries and underwent chemotherapy and radiation following her July 2001 diagnosis and has has since been cancer-free.

Mrs Daniel’s lawyer, Zoe Littlepage, issued a statement saying that “Wyeth has known for decades that postmenopausal drugs cause breast cancer, but the company deliberately failed to do studies to understand or quantify that risk. Wyeth protected their bottom dollar instead of protecting the patients.”

In the court case, Wyeth, which had suggested that Mrs Daniel’s breast cancer had been caused by other risk factors, including family history, denied any malice but has yet to comment on the jury’s decision. The company also noted that Prempro is still on the market and that it had clearly warned users that there was a slightly increased risk of breast cancer from taking the treatment.

This was the third Prempro trial to reach a jury. In the first, a jury last year rejected claims made against Wyeth by another Arkansas woman, while in the second case, a married couple won a $1.5 million award against Wyeth, but the judge declared a mistrial for undisclosed reasons.

The drug’s fall from grace has been spectacular. As many as six million women were thought to be taking Prempro before results from a Women's Health Initiative study in 2002 linked the treatment to a significant increase in risk for invasive breast cancer, coronary heart disease and stroke and Wyeth is currently facing some 5,000 lawsuits involving its HRT products.

Quite how damaging to the firm’s fortunes this decision will be is unclear but it is highly unlikely that Wyeth will have to suffer anything like the multi-billion-dollar lawsuits it endured for the diet drugs fenfluramine and dexfenfluramine. Wyeth had to put aside more than $21 billion to cover the costs of settling the ‘fen-phen’ cases, after the combination was linked to heart valve problems.