Role of biologics as advanced treatment option for Psoriatic Arthritis

Psoriatic arthritis, also called as PsA, is an autoimmune disease that affects the musculoskeletal structures, skin and nails, and at times, the eyes and gut as well. The disease is becoming increasingly prevalent in India. At present, the prevalence of PsA amongst the Indian population is 0.3 to 0.9 %.

On an average, one-fourth of psoriasis patients suffer from psoriatic arthritis as a co-morbidity. Majority of psoriasis patients are not aware about the high risk of developing PsA, due to which the initial symptoms might be left unnoticed, thereby delaying diagnosis. People with no prior disease history of psoriasis, might also suffer from psoriatic arthritis.

Timely diagnosis and early treatment initiation are critical in PsA patients, due to their higher risk of co-morbidities such as obesity, insulin resistance, type 2 diabetes, metabolic syndrome, hypertension, hyperlipidemia, and cardiovascular disease, in comparison to the general population.

Over the last decade, medical research has been focusing on the long-term effects of PsA – erosion and deformity (40%–60% of patients) – which results in worsened mobility and diminished overall quality of life (QoL) in patients. This has also led to a tremendous change in disease management, including better understanding of PsA pathogenesis;  early diagnosis and treatment initiation; newer treatment options; improvement in treatment modalities by targeting lower remission; and timely referrals from dermatologists and physicians to rheumatologists.

One key difference that has emerged in the treatment modality is the advent of advanced biologics, especially interleukin inhibitors, such as IL-17 and IL-12/23, that have revolutionized the management of patients with PsA. These biologics target specific parts of the immune system to slow down disease progression. They work by inhibiting structural damage in the peripheral joints, thereby improving mobility and the quality of life (QoL) of PsA patients. According to a study published in Arthritis Research & Therapy, up to 60 percent of PsA patients achieved minimal disease activity at one year of treatment with biologics.

Much before the commercial availability of biologics that are interleukin inhibitors, nonsteroidal anti-inflammatory drugs (NSAIDs), corticosteroids, and disease-modifying antirheumatic drugs (DMARDs) like methotrexate, were the only primary treatment options available for Psoriatic Arthritis. These drugs are still used as the first-line of treatment.

NSAIDs relieve the pain and have no effect in preventing the progression of joint damage. Corticosteroids are generally used in patients who require rescue therapy and withdrawal of the drug can worsen the psoriasis. DMARDs are generally suitable for patients with mild disease. However, there’s no evidence to show that they prevent or decrease structural damage.

Therefore, biologic therapy is adopted in patients who have moderate to severe PsA and don’t respond to other treatment options. Treatment with biological drugs is also considered when patients develop new erosions or experience worsening of pre-existing erosions.

Since there are no specific treatment protocols or guidelines for the use of biologics, the treatment choice is determined basis the patient’s condition and careful assessments of the associated benefits and risks. Each patient may respond to the treatment differently and therefore might require change or adjustments in the treatment regimen. Overall, studies indicate that biologics remains an effective and safer treatment for longer treatment periods.

At present, there are no controlled trials or case series on the use of biologics in India. The incidence of psoriasis arthritis and its impact on patient’s productivity, warrants for creation of a formal registry, that could help understand and analyze the needs of patients.

About Author: Dr Chandrashekara. S, Professor and Managing Director, ChanRe Rheumatology and Immunology Center and Research, Bengaluru. He is a renowned rheumatologist and Immunologist with over 20 years of consultant grade experience and expertise. He received his MD from Mysore Medical College, Karnataka and DNB in General Medicine from New Delhi, India.

*Views expressed by the author are his own.