Psoriasis: Biologics hope to reach 8mill undiagnosed sufferers
London- Despite almost 20 million sufferers globally, and comorbidities ranging from visible signs of infection to arthritis, there remains no cure for psoriasis and indeed public awareness of the disease remains remarkably low. In fact a new report from independent market analyst Datamonitor* reveals that perhaps as many as 45% of sufferers, or 8 million people** are undiagnosed. However new biologic treatments and marketing campaigns are helping to bring psoriasis more into the public eye, to the benefit of all available products.   

Accelerated skin cell grow 

Plaque psoriasis, the most common form, is a chronic recurring skin disease that causes raised, red patches with silvery scales on top. This occurs because of an abnormally high rate of growth of skin cells and while the exact reason why is unknown, contemporary wisdom suggests that a problem with the immune system plays a role.  

Human skin cells normally mature and shed about every 28 days, however in psoriasis sufferers this cycle may take only three to six days. It is a relatively common condition, affecting 1-3% of the world’s population and sufferers are often genetically predisposed to being affected. While psoriasis is rarely life threatening, it does often result in severe morbidity and disability, says Datamonitor healthcare analyst Clare Churchill. “Datamonitor estimates there are 18 million psoriasis sufferers in the seven major pharmaceutical markets with up to 16% of those developing psoriatic arthritis.”  

“Psoriasis prevalence is low in Japan and east Asia in general, and extremely low to non-existent in ethnic groups native to north and south America,” she says. 

8 million undiagnosed 

Psoriasis currently has no cure, thus current treatments seek to either manage the disease or prevent further outbreaks. It is also currently vastly under diagnosed: Datamonitor estimates that only 55% of sufferers are actually diagnosed. This leaves a very large proportion of psoriasis sufferers- most likely with a mild form of the disease- either self treating with over-the-counter medication or totally untreated, Churchill says. “If the epidemiology estimates for patient volume are applied to these figures, it shows that a total of over 8.1 million patients** are either using non-prescription medication or no medication at all. However this situation will improve as awareness of psoriasis improves due to the extensive marketing campaigns for new biologic treatments entering the market.” 

“I think the awareness of psoriasis has increased tremendously recently

… every year there’s one or two big new exciting drugs, it’s really been

phenomenal, bringing more patients in to see us.” – US opinion leader 

Because there is currently no cure for psoriasis, the goal of therapy is to clear each episode and prevent a recurrence for as long as possible. Doctors generally treat psoriasis in steps based on the severity of the disease, size of the areas involved, type of psoriasis and the patient's response to initial treatments, Churchill says. “In step 1, medicines are applied to the skin (topical treatment). Step 2 uses light treatments (phototherapy), and step 3 involves taking systemic medicines that treat the whole immune system. Variations from this approach include combinations of therapy, which according to physician research are used in increasingly severe patients, with 45% of the most severe patients using a combination of pharmaceuticals and non-pharmacological treatment like phototherapy.” 

Unfortunately, over time affected skin can become resistant to treatment, especially when topical corticosteroids are used. Also, a treatment that works very well in one person may have little effect in another. As a result, doctors often use a trial and error approach to find a treatment that works, and they may switch treatments periodically if a treatment does not work or if adverse reactions occur. 

But ultimately the non-life threatening nature of psoriasis means that physicians are less-willing to take risks with treatment options than for other diseases. Systemic treatments are only used on very severe patients and opinion leaders agree that biologics are also only warranted on the more severe patients. 

“There’s no question that there is a small percentage of patients

who are sufficiently severe, and they’ve had a poor experience with

other treatments, in whom a biologic is clearly justified.” – US opinion leader 

Biologics ahead of the pack 

For severe cases of psoriasis, biologics are emerging as the best form of treatment. The current leading biologics are Biogen Idec and Genentech’s Amevive; Serono, Genentech and XOMA’s Raptiva; Wyeth and Amgen’s Enbrel and Johnson and Johnson’s Remicade. Amevive, Raptiva and Enbrel are all approved for psoriasis in the US but have yet to be approved in the EU, while Remicade is currently undergoing phase III trials for psoriasis and psoriatic arthritis in both the US and EU, Churchill says. “Psoriatic arthritis approval is significant due to the off-label prescribing possibilities for severe psoriasis patients.” 

Datamonitor’s research indicates that among physicians efficacy is weighted as the most important attribute, followed by side-effect severity. The perception among physicians of the importance of side effects in the biologics class may be attributable to the relatively unknown nature of these drugs, Churchill says. “Despite some side effects- infection at the site of injection being the most common- biologics compare well with some other systemic treatments for severe psoriasis such as cyclosporine or methotrexate.” 

“Ultimately, almost all treatments that work for the more severe form of psoriasis impact or target the immune system in some way. The pharmacological rationale behind biologics is that they are more targeted, and should spare the body broad side effects.” 

Maintenance of remission is another unmet need within psoriasis that these treatments aim to fulfil. However only long-term use on the market can really prove the effectiveness of biologics in this attribute. 

On the campaign trail 

However despite the advances being made in treatment, perhaps the biggest challenge is raising awareness of psoriasis and therefore rates of diagnosis. Patient advocacy groups are also taking measures to improve both diagnosis and treatment rates. “In fact the American Academy of Dermatology is launching a public awareness campaign in early 2005 in the US, which coupled with the increased awareness brought about by treatment marketing campaigns, will no doubt help to tackle the ongoing problem of low diagnosis rates,” Churchill says.  

Ends

*Stakeholder Insight: Psoriasis - Biologics Impact Treatment Regimes Across the Globe

**In the seven major pharmaceutical markets: France, Germany, Italy, Japan, Spain UK, USA. 

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