* Bayer, J&J's Xarelto in new class of stroke preventers
* Bristol/Pfizer drug seen in the lead, Xarelto in second
* U.S. FDA panel next week may focus on 'rebound' effect
(Adds details on FDA advisory panels)
By Anna Yukhananov and Ransdell Pierson
WASHINGTON/NEW YORK, Sept 2 An experimental
stroke preventer from Bayer (BAYGn.DE) and Johnson & Johnson
(JNJ.N) is likely to win a recommendation from U.S. health
advisers next week, but not without concern over risks seen
when patients come off the drug.
A key issue for the Food and Drug Administration advisers
may be the so-called rebound effect of the medicine Xarelto.
When patients stopped taking it and resumed older drug
warfarin, higher risk of stroke was seen in trials.
"We think the FDA advisory panel will be concerned that
there's a 'rebound' effect with discontinuing Xarelto," Wells
Fargo analysts said in a research note on Thursday. "However,
our consultants do not believe this will be a deal breaker."
Xarelto's shortcomings may also relegate it to second place
in the marketplace behind a rival treatment being developed by
Bristol-Myers Squibb Co (BMY.N) and Pfizer Inc (PFE.N), in an
anti-clotting market that could top $10 billion a year,
The advisory panel is set to consider the data on Xarelto
next Thursday, after the FDA releases its initial findings on
the drug on Tuesday.
"Key opinion leaders expect a panel recommendation for
Xarelto, but not without controversy," analysts at Leerink
Swann wrote in a note on Thursday.
The FDA usually follows the advice of its advisory panels,
and Xarelto could be approved by November if the pill wins
support at the meeting.
Xarelto is one of several promising entrants angling to
replace risky clot preventer warfarin for people with
dangerously irregular heart rhythms, called atrial fibrillation
AF patients' irregular heartbeats can cause blood to pool,
increasing their risk of blood clots and strokes. But many are
unwilling to take warfarin, which requires regular blood tests,
or are unable to tolerate the old medicine.
Boehringer Ingelheim's Pradaxa is already approved in
stroke prevention, while Eliquis, from Bristol-Myers and
Pfizer, has so far shown the best clinical data, especially for
reducing the risk of major bleeding. [ID: nL5E7JT0KV]
RANKING THE COMPETITION
Jeff Jonas, an analyst with Gabelli & Co, predicted the
advisory panel will recommend Xarelto because of its
effectiveness and acceptable bleeding risk, and its advantages
"Xarelto will be overshadowed by apixaban (Eliquis), but it
is going to be a decent drug and could generate $1 billion to
$2 billion in annual sales, with the marketing muscle of J&J
and Bayer," he said. Bristol and Pfizer plan to submit Eliquis
for U.S. approval later this year for preventing stroke.
Another issue is some inconsistent data. A clinical trial
last November showed Xarelto, known generically as rivaroxaban,
was 21 percent better at preventing stroke in patients with AF
compared with warfarin. [ID:nL6E7JA1V9].
But when all those who entered the trial were evaluated, no
superiority was established for Xarelto, a fact that is likely
to come up in panel discussions.
"A superiority claim over warfarin ... is unlikely in our
view and is not widely anticipated," said Barbara Ryan, analyst
at Deutsche Bank, in a research note on Friday.
Panelists may also focus on the fact that warfarin was not
used as effectively as it might have been in the study, making
it more difficult to compare it with Xarelto.
Xarelto's advantage over rivals may come in its dosing,
since it needs to be taken only once a day as opposed to twice
for Eliquis and Pradaxa, a key factor for elderly patients
taking multiple medications.
Gabelli & Co's Jonas said Eliquis is likely to capture 50
percent or more of the warfarin-replacement market, with
Xarelto in second place comfortably ahead of Pradaxa.
"Pradaxa is being dismissed; it will be relatively small,"
Even though Pradaxa was the first to market, having been
approved by U.S. regulators last year, it causes
gastrointestinal side effects in a significant percentage of
patients and has special storage requirements.
Pradaxa works by directly blocking a protein called
thrombin that plays a key role in the clotting process, while
Eliquis and Xarelto block the Factor Xa protein.
The three medicines -- and a fourth from Daiichi-Sankyo
(4568.T) called edoxaban that is due to report pivotal results
in 2012 -- will greatly expand the number of patients with AF
(Reporting by Anna Yukhananov and Ransdell Pierson, editing by
Michele Gershberg and Matthew Lewis)