In what is claimed to be the largest and longest prurigo nodularis clinical trial to date, long term benefits were seen for patients treated with nemolizumab, a monoclonal antibody that blocks the interleukin-31 receptor A.

One-year data from an interim analysis of the OLYMPIA long-term extension (LTE) study showed that more than 80% of nemolizumab-treated patients with prurigo nodularis experienced improvement in itch and more than 60% achieved clear or almost-clear skin.

Trial investigators said previous studies had not exceeded six months, and the new continuation study results from phase 3 trials that enrolled more than 1700 patients showed that nemolizumab-treated patients who responded at 16 weeks maintained skin and itch responses through to week 48, even when dosing was reduced from every four weeks to eight weeks.

These new data build on results from the phase III OLYMPIA and ARCADIA clinical trial programs and demonstrate nemolizumab’s long-term and long-lasting benefit in prurigo nodularis and atopic dermatitis, respectively, said study sponsor Galderma in a media release from AAD 2024.

According to the results presented at the meeting, at one year 69% of patients who had received continuous nemolizumab treatment and 65% of nemolizumab-naïve patients had reached clearance or almost-clearance of skin lesions, as measured on the Investigator’s Global Assessment (IGA) score. Also, 89% of those who had received continuous nemolizumab treatment and 83% of nemolizumab-naïve patients achieved a significant response on itch intensity as measured by an at least four-point improvement on the peak-pruritus numerical rating scale (PP-NRS).

Improvements in sleep disturbance, as well as quality of life, were also maintained at one year with nemolizumab treatment.

Study investigators said the results also reinforced nemolizumab’s rapid onset of action, with nemolizumab-naïve patients rapidly achieving an at least four-point improvement in itch intensity, as measured by the PP-NRS, as early as week four, consistent with the continuous-nemolizumab cohort.

Results were also reported from an analysis of maintenance data from two pivotal phase III trials of nemolizumab (administered with background topical corticosteroid therapy or topical calcineurin inhibitors) in adolescent and adult patients with moderate to severe atopic dermatitis (ARCADIA 1 and ARCADIA 2).

Out of the patients who had clinical responses to skin lesions at week 16, the majority maintained skin and itch responses at week 48 when receiving nemolizumab every four weeks or eight weeks in the maintenance phase.

About 60% maintained clearance or almost-clearance of skin lesions, when assessed using the IGA score, compared to 50% receiving placebo.

The Eczema Area and Severity Index (EASI)-75 score was also maintained in 76% of those receiving nemolizumab, compared to 64% receiving a placebo.

Itch response, as measured by an at least four-point improvement in weekly average PP-NRS score, was similarly maintained in the majority of patients receiving nemolizumab compared to placebo.

Study investigator Associate Professor Shawn Kwatra, director of the Johns Hopkins Itch Center, in Baltimore, Maryland, said the trial provided evidence that prurigo nodularis can nearly, if not totally, be completely reversed over a one-year period.