Biosimilars Could Provide Greater Patient Access to Psoriasis Treatment

Samantha DiGrande

A recently published review appearing in the International Journal of Molecular Sciences, looks at the factors influencing psoriasis severity and the indications for systematic treatments.

Psoriasis is a common chronic disease that has a considerable impact on patients’ quality of life and on the healthcare system. Treatment approaches to the disease can vary on a case-by-case basis by what is deemed most effective for the patient. A recently published review, appearing in the International Journal of Molecular Sciences, looks at the factors influencing psoriasis severity and the indications for systematic treatments.

The researchers explain that psoriasis’ pathogenesis derives from a combination of genetic and environmental risk factors. Managing the disease requires long-term treatment, which can limit patient options based on safety. The reviewers write that the long-term use of conventional systemic treatments is limited by poor tolerability and cumulative toxicity. In contrast, the long-term use of biologics is advisable, due to better tolerability and safety, although cost presents an issue for sustainability of treatment. However, biologic treatment with a cost-saving biosimilar, such as biosimilar adalimumab (as yet unavailable in the United States), could assist in managing this problem, and open up patient access to higher-cost drugs.

The treatment goals of psoriasis vary per patient and depend on multiple factors. When deciding a treatment goal for a patient, a dermatologist considers not only the severity of skin symptoms, but also the impact of the disease on quality of life. The severity of chronic plaque psoriasis is generally assessed according to the Psoriasis Area and Severity Index (PASI), the body surface area (BSA), and the Physician Global Assessment (PGA). In Europe, the percentage reduction in the PASI score is the standard measure of assessing the decrease in psoriasis severity, and consequently the effectiveness of treatments.

The ultimate goal of therapy is the complete or nearly complete clearing of skin lesions, and an improvement of 90% or greater (a PASI90 response) is currently considered as the most relevant treatment outcome, especially in patients with severe psoriasis. According to the study, treatment goals are generally evaluated between weeks 12 and 16 at the end of the induction therapy. If the goal is evaluated as not being achieved, several strategies can be addressed such as raising the dose of the drug, reducing the time gap between administrations, or combining the drug with another treatment.

Long-term management of psoriasis can be difficult, due to disease evolution being unpredictable. The time interval between episodes of breakouts of psoriasis varies anywhere from a few months to several years. The review found that the long-term use of conventional systemic treatments of psoriasis is limited by poor tolerability and cumulative toxicity, including liver toxicity from methotrexate, renal toxicity from cyclosporine, and skin carcinogenesis from phototherapy. In comparison, long-term use of biologics beneficial for patients due to better tolerability and safety, and the continuous regimen of biologics generally has greater safety and efficacy when compared to an intermittent regimen. However, the review found that the use of a cost-saving biosimilar instead of a biologic allowed for greater patient access.