Tasocitinib (CP-690,550)
BRAND NAME: n/a
GENERIC NAME: Tasocitinib
EXPERIMENTAL/INTERNAL COMPANY NAME: CP-690-550 |
|
| DRUG USE (P OR PsA) | METHOD OF DELIVERY | DEVELOPING COMPANY/COMPANIES |
| Plaque psoriasis | Pill | Pfizer |
Description and Comments
Tasocitinib
(CP-690,550) is an immunosuppressant medication that is being evaluated for its
ability to treat inflammation-based diseases including psoriasis. The
drug is a Janus Kinase (JAK) inhibitor, and it is believed that inhibiting its
target, JAK3, may improve psoriasis symptoms.
The drug showed impressive effectiveness in a Phase Two trial, which was a
relatively small trial that tested different doses of the experimental
drug. In the largest dose tested, 15 mg twice a day, after 12 weeks, 67%
of patients receiving tasocitinib achieved a 75% improvement in psoriasis
symptoms, and 33% achieved a 90% improvement in psoriasis symptoms. (A
75% improvement [known as PASI 75] at week 12 has long been considered the gold
standard and the one the U.S. Food and Drug Administration [FDA] looks at when
evaluating a psoriasis treatment.)
Pfizer is hoping that tasocitinib can become a treatment option that offers
effectiveness comparable to the biologics with the convenience of a pill.
While many psoriasis patients have learned that injection is not a big deal, a
pill is obviously an easier sell. (The drug is also being tested in a
topical formulation, which might reduce side effects.)
More than 4,000 people have participated in tasocitinib clinical trials to date
for psoriasis and other diseases. So far, the most frequently reported
adverse events include headaches, infections and gastrointestinal symptoms such
as nausea, vomiting and diarrhea. More significantly, "[d]ose
dependent decreases in mean neutrophil counts and hemoglobin values and
increases in mean LDL, HDL and total cholesterol levels were observed" in
a Phase Two trial of the drug. Long-term safety data is not yet available
for this new experimental drug. (We may get to see more robust data from
Phase Three trials in rheumatoid arthritis [RA] as soon as November 2010.)
Now underway, Pfizer's Phase Three clinical trial program for tasocitinib in
chronic moderate to severe plaque psoriasis patients is called the OPT (Oral Psoriasis Treatment)
Trials.
Tasocitinib is also being studied as a
potential treatment for RA, Crohn's disease, ulcerative colitis, dry eye, and
to support organ transplants; and given this broad profile, it is hoped that it helps improve psoriatic arthritis as well.
Tasocitinib (CP-690,550) clearly has a
long way to go. It must prove it is effective for longer periods of time
than 12 weeks, and prove it is safe for the long term as well (particularly for
cholesterol levels and white blood cells counts). But let us suggest that
this drug could one day down the road be one of the Holy Grails psoriasis
patients have needed for...oh...a couple thousand years. Here's
why: pills are easily duplicated, while biologics are complex to
create. This means that when the patents for tasocitinib eventually
expire (we do not know how long they have remaining on their patents but it
could be 15 or 20 years), then generics could be produced cheaply for
this. Remember that many psoriasis patients still use methotrexate, a
Korean War-era chemotherapy available as a generic for roughly $50 a month.
Maybe by the year 2030 or so, uninsured psoriasis patients worldwide might have
within reach a cutting edge psoriasis treatment like tasocitinib at generic
prices. Assuming, of course, that it proves safe and effective for
long-term use. Just another reason we are all hoping tasocitinib and the
other experimental treatments being tested pan out.
Other News and Links
Company
news release on Phase Two results, October 2010
JAK
Inhibitors are Steaming Through the Pipeline, Skin & Allergy News, May
2009
