Understanding New Psoriasis Treatments Like Enbrel
The majority of the biologic therapies involve changing the
amount of Tumor Necrosis Factor - Alpha (TNF-Alpha). TNF-alpha
is involved in regulating abnormal responses like inflammation,
increased blood vessel formaton (angiogenesis), and excessive
development of skin cells (keratinocyte proliferation). It can
also affect bone and cartilage erosion hence the reason that
psoriatic arthritis is especially responsive to the new biologic
therapies.
High Levels of TNF-Alpha are found in psoriasis as well as a
host of other conditions including Crohn's disease, juvenile
rheumatoid arthritis, and ankylosing spondylitis.
Interestingly, the severity of psoriasis correlates quite well
with the levels of TNF-Alpha found in the blood.
The goal of the TNF inhibitor biologic therapies is to eliminate
the excess TNF that is present so that you have normal levels.
It is the excess TNF that is associated with the inflammatory
reactions and hence some of the diseases manifestations. All of
the underlying reasons for this are still uncertain.
Early treatments in psoriasis targeted large sections of the
immune system. As we learn more the therapies such as the ones
discussed in this article become more and targeted and affect a
smaller segment of the immune system apparatus.
The three TNF inhibitors are etanercept (Enbrel), infliximab
(Remicade) , adalimumab (Humira).
The medicines at this point appear safe. They should not be used
in patients with a history of tuberculosis and congestive heart
failure. As a dermatologist I have seen enormous improvements in
the quality of life of patients due to these medicines. Caution
still needs to be exercised as these are relatively new
medicines and I feel they should be prescribed only when other
medicines have failed or if there are signs of early and
progressive joint involvement with failure of other medicines.
If one is able to completely control psoriasis with topical
medicines and moderate light exposure / ultraviolet light
phototherapy then this should be continued. I do not feel at
this point that one should use these medicines because of the
"ease" of treatment if other low risk traditional treatments
work.
Due to the cost of these medicines and the profits the drug
companies have the potential to make, there is an aggressive
marketing campaign to promote these drugs direct to people with
psoriasis. As a result, I often have patients who come in
requesting these medicines without them having any knowledge
beyond 30 second commercials.
I tell all patients that at this point they appear safe with the
emphasis on the "at this point." We never know what potential
problems could arise 20-30 years down the road although they do
appear safe. The decision to go on a biologic therapy should be
balanced by several factors. 1) Do you have psoriasis covering a
large part of your body and have conventional treatments that
have been done exactly as prescribed by your doctor failed? 2)Do
you have progressively worsening psoriatic arthritis?
If you have answered yes to either of the above questions you
could be a candidate for these medicines and as always you
should discuss treatment options with your physician.
Unfortunately, the medicines are not able to be taken by mouth.
The simple reason for this is that biologics are proteins in
structure and would be digested if taken by mouth. So, they must
be given by injection or intravenously. The overwhelming
majority of patients have little problem with this. The point I
want to make is that just because they are injectable or
intravenous does not mean that they are stronger with more side
effects than medicine taken by mouth.
In summary, the new biologic therapies in psoriasis and other
diseases like Crohn's and Rheumatoid Arthritis are a great
advance in treatment and have improved the quality of life of
many people suffering from the above diseases. They represent a
whole new way of targeted treatment and are best used when safe,
well known traditional treatments have failed.