Patient volume unchanged
The size of the patient population for this disease has been a driving factor for investment, with an estimated prevalence range of 0.5% up to 11% in some populations (Michalek et al., 2017), compared to rheumatoid arthritis prevalence of just 0.5-1% (Gabriel, 2001). However, as shown by the below graphic, the volume of the market is expected to show modest growth, which is in line with the rest of the prescription market over the next 10 years. It is the large forecast growth in sales, driven by expensive biologic therapies that sets this disease apart.
Confidence in biologic therapy for psoriasis recovered
The uptake of biologic therapy was comparatively slow in Dermatology initially, likely influenced by the issues seen with the first biologic for psoriasis, a CD11a inhibitor. This injectable treatment was launch in 2003 but subsequently removed from the market in 2008 due to serious side-effects, leaving Dermatologists sceptical of novel target biologics. The TNF inhibitor biologics have since proven the safety and efficacy of biologic treatment in psoriasis, despite the need for higher dosing than other autoimmune diseases at times, and uptake has been steady for this disease.
Biologic use in a small proportion of patients
Many of the large psoriasis patient pool goes untreated. Within the treated population IQVIA volume data suggests that 80% of the comparative prescription drug volume (patient days) is for topical therapies, leaving 20% of the patient days for a form of systemic treatment in 2017. Patients often use treatments in combination, so it is important to note that the patient days metric does not translate directly to patient numbers.
The use of systemic treatments does vary by region, driven by both prescribing habit and patient access to the more expensive treatments. Europe, the Americas and MENA show higher proportional use of topical therapies.
IQVIA data suggests that an even smaller proportion of patient days, just under 8%, were for a biologic therapy in 2017, as shown in the graphics below.
The below forecast models switching of patient volume to new launches from existing biologics, but if just a small proportion of currently topically treated patients, also receive a new biologic, the size of this market could grow considerably more. The below graphic also shows how the proportion of sales for biologic therapies is eroded over the forecast period by biosimilar launches, and novel oral kinase and PDE4 inhibitors.
* 2018 contains Q3 2018 historical data.
Now a new generation of Dermatologists and a new generation of biologics combine to show the events of a decade ago no longer shape prescribing. The market looks set to show significant sales growth as patients gain access to more of these highly effective treatments, and the effect is expected to spread to other dermatologic disorders as biologic treatments launch in areas such as atopic dermatitis.
For more information on brand and country specific forecasts in any disease, please contact IQVIA and request a demonstration of Forecast Link, an online tool containing 5 years historical and 10 years of forecast data in 73 countries, for 10,000 drugs and over 600 diseases.
Michalek IM, Loring B, John SM. A systematic review of worldwide epidemiology of psoriasis. J Eur Acad Dermatol Venereol. 2017 Feb;31(2):205-212.
Gabriel SE. The epidemiology of rheumatoid arthritis. Rheum Dis Clin North Am. 2001;27:269–281.