Nexavar, a kidney cancer treatment from
, helped patients live longer than a placebo, but the difference failed to meet the goal of a late-stage study of the drug.
Data from the phase III trial showed that patients getting Nexavar lived for 19.3 months, compared with 15.9 months for those taking a placebo. Of the placebo group, 48% of them were eventually switched to Nexavar. The Food and Drug Administration approved Nexavar for use against advanced kidney cancer last December.
Shares of Onyx sank $2.90, or 14.6%, to $16.92 on the news, putting the stock well below its 52-week closing low of $18.80. Volume was extremely heavy, with nearly 10 times as many shares trading as on an average day.
Bayer, which trades an American depositary share in the U.S., was losing 25 cents, or 0.6%, to $44.55.
Factoring out the patients who switched, those in the placebo group lived for 14.3 months. The data didn't reach the prespecified target that would have been required to stop the overall survival analysis early, but they do "suggest a favorable survival trend for patients who received Nexavar," the companies said Monday.
The results were based on 367 patient deaths. A final analysis of the trial is planned when 540 patients have died. The data were presented by Dr. Tim Eisen at the annual meeting of the American Society of Clinical Oncology in Atlanta. Eisen is the consultant medical oncologist at The Royal Marsden Hospital in London.
"Consistent with the original interim analysis, patients receiving Nexavar lived longer than patients receiving placebo, despite almost 50% of placebo patients crossing over to Nexavar," Eisen said. "These data are encouraging and should be considered preliminary pending the final analysis."
Also during the study, Nexavar demonstrated that it could benefit progression-free survival rates without hurting patients' overall quality of life. Progression-free survival measures the length of time that a patient lives without evident tumor growth or death. The drug also helped individual symptoms, such as cough, fevers and shortness of breath.
Nearly 208,000 people worldwide are diagnosed with kidney cancer each year and more than 102,000 die from the disease annually.
Over the weekend at ASCO,
said its kidney-cancer drug Sutent almost doubled progression-free survival time in patients who took it as a first-choice treatment instead of a standard treatment.
The trial involved 750 patients with a type of kidney cancer called advanced clear-cell carcinoma. The patients hadn't had chemotherapy, but most of them had their cancerous tumor and diseased kidney removed. Patients either received Sutent or interferon-alpha, a standard kidney cancer treatment. Sutent is already approved to treat kidney cancer.
Also during the conference,
said temsirolimus, used alone and as a first treatment, significantly increased the overall survival of patients with advanced kidney cancer compared with interferon-alpha.