Thyroid Cancer Drug From Bayer, Onyx Helps Halt Disease's Progress

   By Joseph Walker 
 

Bayer AG (BAYN.XE, BAYRY) and Onyx Pharmaceuticals Inc. (ONXX) said their drug Nexavar helped to nearly double the number of months that patients with a rare type of advanced thyroid cancer lived without their diseases worsening--but that the drug made no difference in patients' overall survival.

Despite the lack of overall survival benefit in the late-stage trial, the companies said they would seek regulatory approval later this year to sell the drug for the disease. Patients with treatment-resistant thyroid tumors have no other treatment options, study investigators said, and if Nexavar is approved it would be the first new drug for this type of thyroid cancer in 40 years.

Nexavar stalled the growth or spread of tumors five months longer than in patients receiving placebos, which could have a positive impact on patients' quality of life, said Marcia Brose, assistant professor at the Perelman School of Medicine at the University of Pennsylvania and the study's lead investigator. Treatment-resistant patients have a life expectancy of up to three years and six months, a period in which complications of the cancer's spread--including pneumonia and severe bone pain--can multiply.

"For these patients, a longer progression-free survival means more months without hospitalization and invasive procedures to control pain and other symptoms," said Dr. Brose, who is a paid consultant to Bayer and Onyx.

Profits from Nexavar, which is approved in 100 countries for kidney cancer and liver cancer, are split between Bayer and Onyx. The drug had sales of roughly $900 million last year. An expanded approval for thyroid cancer could result in an additional $300 million in peak global sales annually, said Ying Huang, a Barclays analyst.

The increased sales likely would be more meaningful for Onyx, whose market value is roughly $7 billion, or about a 12th of the size of Germany's Bayer. The potential for Onyx's drug Kyprolis, which was approved last year for multiple myeloma and is projected to reach $1 billion in annual sales by 2016, has helped lift the company's share price 26% this year to $95.45. But Onyx is hoping that additional indications for Nexavar can help increase sales and offset research and development costs as it looks to become profitable.

"We've got a great opportunity in markets around the world where Nexavar is continuing to grow," Tony Coles, Onyx chairman and chief executive, said in an interview.

The study results were scheduled to be presented Sunday at an annual meeting of the American Society of Clinical Oncology in Chicago. Side effects, including weight loss and high blood pressure, caused nearly 19% of Nexavar patients to discontinue the drug, and there were two patient deaths in the study.

One of the deaths occurred when a patient taking Nexavar had a heart attack, said Dr. Brose, noting that cardiac complications are a known side effect of the drug. The other death occurred in the placebo arm of the trial, and it may have resulted from a blood thinner medication. Dr. Brose said that in a study of more than 400 patients with advanced disease, the deaths weren't concerning.

"To have only have two patients deaths," Dr. Brose said, "was really reassuring."

A combination of surgery and radioactive iodine can cure most people with differentiated thyroid cancer, but as many as 10% of the 60,000 patients diagnosed annually develop a resistance to radioactive iodine, a liquid substance commonly used in combination with surgery to destroy cancerous cells.

Mr. Coles estimated that between 3,000 and 4,000 patients could be eligible for the drug in the U.S., in addition to a similar number in Europe. The thyroid is a gland in the neck that regulates the body's metabolism and weight.

Nexavar is among the most expensive cancer therapies, with a monthly wholesale cost of $9,790, or about $117,500 annually.

Onyx earlier this year said the study met its primary endpoint. Before Sunday's presentation, some analysts said they didn't expect the detailed results to affect Onyx's stock price. The drug has been recommended for off-label use in resistant thyroid cancer by the National Comprehensive Cancer Network since about 2010, and many insurers already will pay for the drug, said Barclays's Mr. Huang in an interview.

The phase three study looked at 417 patients with metastatic thyroid cancer who had developed a resistance to radioactive iodine. Patients were randomly assigned to receive either Nexavar, known by its generic name as sorafenib, or a placebo.

The study met its primary endpoint of increasing the time patients lived without their tumors getting worse, called progression-free survival, or PFS. Patients on Nexavar had a median PFS of 10.8 months, which was statistically superior to the 5.8 months experienced by patients on placebo, though shy of the roughly 18-month PFS the drug produced in a previous, midstage study.

The drug hasn't shown a statistically significant improvement in overall survival for patients, which was a secondary endpoint in the study, Onyx said.

Write to Joseph Walker at [e-mail]

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