By Ransdell Pierson
Oct 9 A high dose of Pfizer Inc's drug,
tofacitinib, proved as effective as the widely used treatment
Enbrel in treating adults with moderate-to-severe psoriasis in a
late-stage study, while a lower dose of tofacitinib was less
effective than Enbrel, the drugmaker said on Wednesday.
Analysts said the mixed results, from a 12-week study called
OPT Compare, suggest there would be limited demand for
tofacitinib as a treatment for psoriasis if it is eventually
approved for the inflammatory skin condition affecting more than
7 million Americans.
The study examined the effectiveness of both 5 milligram and
10 milligram twice-daily doses of oral tofacitinib with a
placebo and with the approved twice-weekly starting dose of
Pfizer said tofacitinib, already approved to treat
rheumatoid arthritis under the brand name Xeljanz, showed
similar dose-response trends and similar safety trends as those
seen in an earlier mid-stage trial of tofacitinib for treatment
ISI Group analyst Mark Schoenebaum said the findings suggest
that tofacitinib, at the 10 milligram dose, has "biologic-like
efficacy," meaning effectiveness on par with costly biotech
drugs like Enbrel that are grown in living cells.
But Schoenebaum noted that although tofacitinib had been
studied at both the 5 milligram and 10 milligram doses for
rheumatoid arthritis, it was only approved for the 5 milligram
dose due to concerns of increased safety risk of the higher
"As a result, there is a risk that only the 5 milligram dose
is approved in psoriasis and dermatologists will view
(tofacitinib) to be inferior to Enbrel and other biologics with
a similar and less robust pool of long-term safety data,"
Citi analyst Yaron Werber said mid-stage trials of
tofacitinib showed serious side effects at all dosages,
including cardiovascular events, elevated cholesterol and
decreases in hemoglobin.
"Based on our doctor checks, the safety of tofacitinib is
not clean enough to garner broad use by the risk-averse
dermatology community," Werber said in a research report.
Xeljanz, approved last November for rheumatoid arthritis,
had second quarter sales of $22 million. But some industry
analysts expect it to eventually capture annual sales of $1
billion or more, as an alternative to injectable biotech
arthritis drugs like Enbrel and Abbott Laboratories Inc's
Humira that have their own side effect issues.
On Wednesday, Pfizer said tofacitinib met its primary
effectiveness goal in a separate Phase III psoriasis study,
called OPT Retreatment, which lasted 56 weeks and compared the 5
milligram and 10 milligram doses of tofacitinib to a placebo.
That study compared the effectiveness and safety of
withdrawal and retreatment with both tofacitinib doses, compared
with placebo, in adult patients with moderate to severe
A greater proportion of patients taking tofacitinib
maintained symptom relief during the withdrawal of treatment
compared with patients who switched to placebo, Pfizer said in a
Pfizer said full data from the pair of Phase III studies,
the first of five late-stage trials of tofacitinib for
psoriasis, will be presented at a future scientific meeting.
Data from two more of the large studies is expected in the
second quarter of 2014, Pfizer said.
Shares of Pfizer slipped 0.3 percent in midday trading on
the New York Stock Exchange.
Psoriasis is a chronic inflammatory disease of the skin,
which also affects nails, joints and other organs. An estimated
125 million people worldwide have the condition, according to
Pfizer, including 7.5 million in the United States.
The disease is caused partly by an overactive immune system,
which causes the body to grow skin cells up to 10-fold faster
than normal. The cells build up on top of each other to form
raised red patches of plaque on the skin.
Enbrel, a blockbuster product sold by Amgen Inc and
Pfizer, works by blocking a protein called tumor necrosis
factor, that is linked to inflammation.
Tofacitinib is a so-called JAK inhibitor, as it blocks an
enzyme called Janus kinase that is also associated with