Sprycel tops Gleevec in newly diagnosed CML-study

* Sprycel complete cytogenic response 77 pct vs 66 pct

* Major molecular response 46 pct vs 28 pct for Gleevec

* Novartis drug Tasigna tops Gleevec in similar study

By Bill Berkrot

NEW YORK, June 5 (BestGrowthStock) – Bristol-Myers Squibb’s (BMY.N: )
cancer drug Sprycel may be superior to the already highly
effective standard medicine Gleevec in treating newly diagnosed
patients with chronic myeloid leukemia, according to results of
a clinical trial.

Sprycel, known chemically as dasatinib, is currently
approved to treat chronic myeloid leukemia (CML) patients who
have become resistant to, or cannot tolerate, Gleevec, which is
sold by Swiss drugmaker Novartis (NOVN.VX: ).

Bristol hopes to use data from the study to convince health
regulators that Sprycel should be approved as an initial
treatment for the blood cancer, which could significantly
increase sales. Sprycel, a relatively new product that Bristol
is counting on for profit growth, had first-quarter sales of
$131 million.

Bristol’s Sprycel and a newer Novartis drug, Tasigna, may
improve on Gleevec’s remarkable success in treating CML. The
older drug sent the CML 10-year survival rate from less than 20
percent up to 90 percent, researchers said.

The 519-patient study looked at response of the cancer
after 12 months, a potential predictor of what long-term
patient survival could be with Sprycel, which, like Gleevec, is
a pill taken once a day.

“What we find at 12 months is that Sprycel is associated
with a significantly higher rate of complete cytogenetic
response,” said Dr Hagop Kantarjian, who will present the data
at the American Society of Clinical Oncology (ASCO) meeting in
Chicago on Saturday.

Complete cytogenic response — defined as the disappearance
of the CML cells, or tumor, — occurred in 77 percent of
Sprycel patients after 12 months compared with 66 percent for
Gleevec, known chemically as imatinib. The result was
considered to be statistically significant.

The study also looked at major molecular response, or a
reduction of CML burden by 99.9 percent, which typically means
that the risk of the CML transforming into a more aggressive
phase of the disease becomes extremely low.

The major molecular response rate was 46 percent with
Sprycel versus 28 percent with Gleevec.

“Both complete cytogenic response and major molecular
response, when they are achieved, are associated with better
long term outcomes at five and 10 years,” explained Kantarjian,
chairman of the leukemia department at MD Anderson Cancer
Center in Houston.

Progression to the more aggressive phase of CML was seen in
5 Sprycel patients, or 1.9 percent, and 9 Gleevec patients, or
3.5 percent. None of them had achieved major molecular
response.

A similar study being presented at ASCO found that Tasigna,
or nilotinib, also had significantly higher response rates than
Gleevec.

The newer Novartis drug had a major molecular response of
44 percent and 43 percent at two tested doses compared with 22
percent for Gleevec after 12 months.

All three drugs belong to a class called tyrosine kinase
inhibitors that target a family of proteins highly active in
many types of cancer cells. The drugs attach to the protein
site and deactivate messages that tell leukemic cells to become
malignant, causing the cancer cells to die.

Only much longer studies can fully determine if the newer
drugs can keep patients alive, without disease progression,
longer than Gleevec, which has set a very high bar.

“We think that the new tyrosine kinase inhibitors is a
major improvement over what has been already a highly
successful and revolutionary treatment,” said Kantarjian.

“At this stage we consider both drugs to be probably
superior to the standard of care, imatinib,” he said, using the
chemical name for Gleevec.

“The side effects or toxicities with both the new drugs on
average are less than with Gleevec,” Kantarjian said.

He said there were fewer instances of nausea, vomiting,
muscle cramps and muscle aches, fluid retention or weight gain
in the Sprycel patients.

Researchers did see higher rates of low blood cell counts
and fluid around the lungs with Sprycel, but it was mostly mild
to moderate.

Kantarjian, who worked on both studies, said Sprycel and
Tasigna “on average appear to be equally effective,” but he
noted they have not been tested against each other.

“I think both drugs will likely be approved for the front
line treatment of CML,” Kantarjian predicted.

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(Reporting by Bill Berkrot; Editing by Tim Dobbyn)

Sprycel tops Gleevec in newly diagnosed CML-study