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.
Dr. Brose said the study's design may have skewed the overall
survival results. Patients in the study's placebo arm were allowed
to begin taking Nexavar after their tumors had progressed, meaning
that they may have lived longer because of the drug, thus reducing
the apparent benefit of Nexavar compared to placebo. Roughly 71% of
placebo patients began taking Nexavar after their tumors had
grown.
Write to Joseph Walker at joseph.walker@dowjones.com
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