Psoriasis is a skin inflammation which is a papulosquamous disease with variable morphology, distribution, severity, course, and duration.
According to the WHO report 2016, studies on Psoriasis epidemiology have demonstrated varying prevalence rates across the globe (0.09–11.4%), with an apparent upward trend in several countries.
Psoriasis Epidemiology: Regional Analysis
A regional analysis published in a study by Parisi et al. shows that Psoriasis prevalence ranges from 0.73% to 2.9% in Europe and from 0.7% to 2.6% in the US. This upward Psoriasis trend contrasts with the rates observed in Latin Americans, Africans, and Asians (China, Sri Lanka, Taiwan, Japan), which varied from no cases detected to <0.5% of the population.
A common, chronic, and recurrent skin disease, Psoriasis affects approximately 8 million Americans, with a Psoriasis prevalence of 2– 4% in the United States, as revealed in a population estimates done by the National Psoriasis Foundation.
The Japanese national claims database estimated the psoriasis prevalence in Japan was reported to be 0.34%, lower than the US and Europe. Interestingly enough, of all the total Psoriasis cases about 60% were male with more of older people. So far, there has been no definite conclusions on gender influence. However, most of the studies reported that psoriasis is more common in men compared to women.
Involving a multifactorial pathogenesis process triggered by a combination of genetic and environmental factors, Psoriasis is clinically classified into two groups: Pustular Psoriais and Non-Pustular Psoriasis. Nonpustular psoriasis is further subdivided into Psoriasis vulgaris (early and late-onset), Guttate psoriasis, Erythrodermic psoriasis, Palmoplantar psoriasis, Psoriatic arthritis (PsA), and Inverse psoriasis.
The Pustular variant of the psoriasis is additionally subdivided into generalized and localized forms. The most familiar form is plaque psoriasis with sharply circumscribed, round-oval, or nummular plaques. Erythrodermic psoriasis is a severe form of psoriasis, even though it is rarest and potentially life-threatening.
Of the total Psoriasis cases, 79% were of chronic plaque psoriasis, followed by, guttate which accounted for 10%, and Intertriginous, Pustular and Erythrodermic Psoriasis with varying percentages.
Psoriasis Therapeutics Market
The Psoriasis therapeutic market is primarily driven by topical therapies, phototherapy, systemic medications, and biologics.
The Psoriasis Treatment Prescription varies depending on the severity of the symptoms among patients. According to the National Psoriasis Foundation, for moderate-to-severe psoriasis, treatment with UVA/UVB phototherapy, oral systemic therapies (i.e., methotrexate, cyclosporine, and retinoid), is administered and mild Psoriasis is generally treated with topical therapies (emollients, topical corticosteroids, vitamin D analogues) alone. However, these classic therapies have not completely met patients’ needs, especially in the most severe cases.
Topical corticosteroids are the most widely prescribed option for Psoriasis treatment because of their short-term efficacy, a high degree of acceptability to patients, and relatively low-cost. Although many corticosteroids, including betamethasone valerate, fluocinolone acetonide, and triamcinolone acetonide, are effective, their benefit does not persist for more than a few months. Recently, a topically applied derivative of vitamin D, Calcipotriene got approved as Psoriasis therapy for patients with mild-to-moderate plaque psoriasis.
Systemic therapy mostly includes Cyclosporine, Retinoid, such as Acitretin and Methotrexate. Cyclosporine, known to be the most common Psoriasis treatment, is used to treat patients with extensive psoriasis. Furthermore, Phototherapies, which use Ultraviolet light A (UVA), is in the current treatment practices due to their advantages in cost and application. Treating psoriasis with a UVB light unit at home can be an economical and convenient choice. Stable plaque psoriasis, guttate psoriasis, and psoriasis of the palms and soles are most responsive to PUVA treatment. FDA has given its recommendation to excimer laser for treating chronic, localized psoriasis plaques emit a high-intensity beam of UVB. However, there is not yet enough long-term data to indicate how long improvements will last following a course of laser therapy.
Biological therapy became available for psoriasis with the introduction of Alefacept at the beginning of this century. Up to then, systemic treatment options comprised small molecule drugs, targeting the immune system in a nonspecific manner. In the past decade, a better understanding of disease immune-pathogenesis has been successfully translated into new drugs, known as “biologics,” targeting key inflammatory mediators and currently representing an effective third-line therapy in moderate-to-severe psoriasis patients, unresponsive to non-biologic systemic agents. And yet most people living with psoriasis are either dissatisfied with their treatment or not using treatments appropriate to their level of disease severity. In common with other immune-mediated complex diseases, there is no definitive cure for psoriasis, and available treatment is only to decrease disease activity and improve symptoms.
Several new therapies for moderate-to-severe psoriasis have been approved, primarily driven by the development of targeted biologics. Several key pharma companies are involved in the development of Psoriasis therapy market.