Monoclonal Antibody Provides Itch Relief for Prurigo Nodularis

By Gene Emery

February 21, 2020

NEW YORK (Reuters Health) - An experimental treatment for prurigo nodularis (PN) can reduce itching by 53% over four weeks, according to a phase-2 test of subcutaneous nemolizumab. The reduction was only 20% with placebo therapy.

However, the improvement came at a cost of some gastrointestinal and musculoskeletal problems.

The chronic and often-debilitating disease creates hard, extremely itchy nodules on the skin in sizes up to a half-inch across, usually on the outer arms, shoulders and legs. Sufferers may have only a few or hundreds of nodules. Scratching them can make more appear. The cause is unknown and there are no therapies approved by the U.S. Food and Drug Administration (FDA).

"The patients in the trial had had disease for longer than 6 months; in the nemolizumab group, more than one third of the patients were clear or almost clear of lesions within a period of 3 months, and itch began to abate within the first week," Dr. Sonja Staender, head of the Center for Chronic Pruritus at the University Hospital Munster in Germany, and colleagues write in the New England Journal of Medicine.

The study is the "first randomized clinical trial to demonstrate a significant efficacy of a drug on prurigo nodularis lesions," she added in an email to Reuters Health.

"The results of this trial provide hope for this population of patients with intractable itch," Dr. Shawn Kwatra of Johns Hopkins University School of Medicine said in an accompanying editorial.

Swiss-based Galderma paid for the test. The company announced December 9 that the FDA had given the drug a breakthrough therapy designation. A phase-3 test "will start recruiting in May 2020 in the U.S. and in the E.U.," Dr. Staender said.

All of the 70 study participants had moderate to severe PN. All had at least 20 nodules and rated their itching as at least a 7 on an 11-point scale, with the highest number being the worst-imaginable itch. The injections of the monoclonal antibody were given at weeks 0, 4 and 8.

The patients in both groups enrolled with a peak itch-scale score of 8.4. It dropped to 3.9 points among nemolizumab recipients and 6.7 among volunteers who received placebo (P<0.001).

Also by the fourth week, while only 13.9% of placebo patients reported that they had moderate improvement or had improved to the point where they had no pruritus anymore, the rate was 67.7% with nemolizumab.

Although 81.8% of placebo patients and 70.6% of nemolizumab patients initially reported that PN was having a large or very large effect on their quality of life, by week 12 those ratios had dropped to 41.3% and 16.7% respectively.

The quality of sleep - a big problem for PN sufferers - improved by 56.4% with the drug versus 26.6% with placebo as measured on a different 11-point scale.

Dr. Staender said in her email that "currently no data (are) available on the maintenance of the effect."

She said the phase-3 study will address whether the drug would have to be taken for life. "Without any treatment and medical care, PN will not fade and will get worse," she said.

Gastrointestinal side effects such as abdominal pain were seen in 21% of nemolizumab recipients versus 14% with placebo. The rates of musculoskeletal or connective-tissues disorders such as arthralgia, muscle spasms, fibromyalgia, or spine, jaw or back pain were 18% with the drug and 14% with placebo.

Dr. Staender said the side effects were comparable to those seen in the placebo group "and such side effects were not observed in the ongoing atopic dermatitis program" which is also testing nemolizumab.

Whether the results would apply in the U.S., where PN sufferers are more likely to be black, is uncertain, Dr. Kwatra said in his editorial. The new study was mostly done on whites in Europe.

Dr. Staender reports financial ties to Galderma.

SOURCE: and The New England Journal of Medicine, online February 19, 2020.