Not Scratching the Itch: Thinking Beyond Skin Clearance in Plaque Psoriasis

Clinical trials focus on skin appearance. Patients have more on their minds.

The current benchmark for efficacy in clinical trials of new plaque psoriasis treatments is a 75 percent reduction in the Psoriasis Area and Severity Index (PASI), which is a measure of the area of skin affected along with the skin’s appearance. But the most bothersome symptom, according to a survey of patients with plaque psoriasis, was not skin appearance, but itching.

As thousands of dermatologists gather at the 27th European Academy of Dermatology and Venereology Congress in Paris to discuss the latest data from ongoing clinical trials in psoriasis, Dr. Colby Evans, M.D., a dermatologist in Austin, TX, and also the immediate past chair of the Board of Directors of the National Psoriasis Foundation, discusses how researchers measure the effectiveness of treatments in clinical trials and how those measurements could be more comprehensive.

How do researchers measure the effectiveness of new plaque psoriasis treatments in clinical trials?

“Efficacy of plaque psoriasis treatments has immensely improved over the last 20 years, making more ambitious endpoints realistic. While a 75 percent reduction in PASI score has been the Food and Drug Administration’s benchmark, we see a growing interest in PASI 90 or 100 in more current trials. We want to get patients as close as we can to PASI 100. That being said, achieving a PASI 50 along with an improvement to quality of life is still clinically beneficial.”

DR. COLBY EVANS, M.D.

DR. COLBY EVANS, M.D., FROM THE NATIONAL PSORIASIS FOUNDATION BELIEVES THAT THERE IS ROOM FOR IMPROVEMENT IN THE MEASUREMENT AND GOALS OF EFFICACY IN PSORIASIS CLINICAL TRIALS.

Does PASI comprehensively capture all the clinical benefits of psoriasis treatments?

“PASI measures the size, as well as the level of scale, redness and thickness of psoriasis plaques. It does not capture other debilitating symptoms associated with psoriasis, such as psoriatic arthritis, itching or social stigma.”

How impactful are those symptoms on the lives of patients with plaque psoriasis?

“Itching can be debilitating and miserable, and can interfere with daily functioning. Survey data showed that people with psoriasis reported having a higher level of sleep-related problems compared to the general population.

Psoriatic arthritis is also of high concern among patients with psoriasis. Approximately 30 percent of plaque psoriasis patients develop psoriatic arthritis. It’s painful, can distort the joints and can be permanently disabling if untreated.”

What are the potential consequences of not capturing improvements in these symptoms?

“It’s important to take full measure of the patient and their life before you decide on treatment. PASI is a reasonable place to start, but it is more complicated than just the extent and thickness of their plaques. If you’re ignoring specific symptoms, patients can get left behind, and treatment decisions may be made without factoring in critical information.”

The more safe and effective treatment options we have, the better for patients with plaque psoriasis.

Do you measure PASI to make treatment decisions for patients who are not in clinical trials?

“In the real world, outside of trials, we don’t use a strict algorithmic treatment of psoriasis. In the regular clinical setting, I am more interested in knowing if the patient can live their life socially, occupationally and recreationally, and without feeling limited by their psoriasis. If they are, I know we’re on the path to success.”

How can clinical trials evolve to more comprehensively measure meaningful improvements for patients with plaque psoriasis?

“It’s becoming fairly common to have secondary endpoints that include itching and quality of life, which is progress. We’re seeing better management of psoriasis sub-types, such as patients with severe hand and foot psoriasis or patients who have severe arthritis without a lot of skin disease. Since the condition is quite diverse, there’s no one treatment for every patient. So the more safe and effective treatment options we have, the better for patients with plaque psoriasis.

With that in mind, many people who have had plaque psoriasis for decades aren’t aware of some of the new treatments. So a tremendous amount of patient education needs to be done.”

To learn more about treatment challenges that patients with psoriasis continue to face, read “Moderate Psoriasis Patient Needs Should Not Be Overlooked.”