Palmoplantar pustulosis patients pin hope on Skyrizi’s approval

Skyrizi (risankizumab) has emerged as a new option for treating palmoplantar pustulosis (PPP), a condition characterized by pustules, exfoliation, and red patches on the palms of the hands and feet that impair quality of life.

AbbVie Korea held a media event on Monday to commemorate the approval of its psoriasis drug Skyrizi for treating PPP at Andaz Seoul Gangnam. The Ministry of Food and Drug Safety (MFDS) approved Skyrizi Prefilled Pen Injection 150mg/ml this month as a treatment for PPP.

At the event, Professor Baek Yoo-sang of the Department of Dermatology at Korea University Guro Hospital spoke on the topic of “The latest advances in the treatment of palmoplantar pustulosis (PPP) and the clinical significance of Skyrizi in the treatment of dry skin diseases.”.

Palmoplantar pustulosis is characterized by rashes, blisters, red spots, and sterile pus on the hands' fingers and toes or palms, accompanied by intense itching and pain. The cause of the condition is still not fully understood, but genetic abnormalities, tobacco use, and infections are thought to be major environmental factors.

The lesions are usually limited to the palms of the hands and feet, but sometimes, symptoms appear in areas other than the palms, such as the nails. In some patients, pustular arthritis osteoarthritis (PAO) occurs as a joint comorbidity, invading the anterior rib cage.

The number of Korean PPP patients was estimated to be around 10,000 in 2022, with a prevalence rate of less than 0.02 percent of the total population. In Japan, a demographically similar country, 0.12 percent of the population about 150,000 people) were diagnosed with PPP, and the prevalence of psoriasis was 0.34 percent in the same study.

The disease lasts for years or decades, with symptoms worsening and, in most cases, severity not improving over time.

"People with palmoplantar pustulosis have difficulty working with their hands, such as typing, making it difficult to participate in economic activities," Professor Baek said. “Activities, including exercise, are also difficult, greatly reducing their quality of life. The burden of disease is also very high. It's even higher than plaque psoriasis."

Existing treatments include topical steroids, phototherapy, and systemic oral medications, and biologics can be used if these treatments do not improve symptoms. Janssen's Tremfya (guselkumab) is approved and covered by health insurance for treating PPP.

"Biologics can be an effective option for treating psoriasis, psoriatic arthritis, and palmoplantar pustulosis," Professor Baek said, introducing Skyrizi’s clinical role in treating psoriasis.

From a clinician's perspective, the more treatment options, the better. Currently, immunosuppressive drugs are used to treat PPP, but long-term use can lead to side effects, such as hair loss and hepatotoxicity, Baek pointed out.

"The longer dosing interval of risankizumab compared to guselkumab is an advantage, with a dosing interval of three months for maintenance therapy," he added.

Although Skyrizi has emerged as a new treatment option, problems remain. Last year, the Korean Society for Psoriasis requested that PPP be designated as a rare disease, but the request was denied. The organization has reapplied for the rare disease designation.

"Unfortunately, it has not received the special designation for rare disease calculation. Currently, out-of-pocket expenses for patients with PPP are quite high,” Professor Baek said. “As mentioned earlier, they have difficulties with economic activities and a high-cost burden. That drives patients back to existing treatment despite the new treatment’s high effectiveness.”