Recombinant IL-2 Shows Potential in Atopic Dermatitis

BERLIN — A novel regulatory T-cell–stimulating therapy appears to significantly improve atopic dermatitis in patients with moderate to severe disease and may even benefit quality of life, suggest results from a phase 1b trial.

The research was presented at the annual meeting of the European Academy of Dermatology and Venereology on October 13.

More than 40 patients were randomly assigned to receive one of two doses of a highly selective recombinant interleukin (IL)-2 conjugate, rezpegaldesleukin or placebo for 12 weeks, after which responders were observed out to 48 weeks.

The higher dose was associated with significant improvements in Eczema Area and Severity Index (EASI) and Body Surface Area (BSA) scores, which were maintained over the course of the study, as well as trends for improved patient reported outcomes.

"This is the first study to demonstrate the therapeutic potential of rezpegaldesleukin," said presenter Jonathan Silverberg, MD, PhD, MPH, associate professor of dermatology and director of clinical research at The George Washington University School of Medicine and Health Science, Washington, DC.

He added, "These may be some of the most compelling data to date for the field, proving that, at a high level, if you causally increase regulator T cells, you will take down inflammation and improve a disease state.

"For me, this is proof of concept for so many things, and it gets me very excited."

Silverberg noted that with the response maintained out to 48 weeks, despite stopping therapy at week 12, the "hope" with the approach of inducing regulator T cells "is that we could induce tolerance and that we could have some potential for disease modification."

He continued, "Maybe I daren't use the word 'cure,' but can we at least get to something that is truly remitted, where they can stop the drug and maintain that response?"

Silverberg said rezpegaldesleukin is now being evaluated in a phase 2b study for moderate to severe atopic dermatitis, and a phase 2b trial for alopecia areata is in development.

Tiago dos Reis Matos, MD, PhD, MSc, Amsterdam University Medical Centers, Amsterdam, the Netherlands, who was not involved in the study, told Medscape Medical News that "recombinant human interleukin-2 is an original therapy."

Instead of blocking or inhibiting inflammation, it stimulates the patient's immune system to "restore a healthy balance."

He explained that it "stimulates regulatory T cells, which can be seen as the Peace Corps of the immune system, responsible for maintaining the equilibrium and avoiding uncontrolled inflammation." 

At the meeting, Silverberg told the audience that although they are the "beneficiaries of riches of new advances" in atopic dermatitis, "still, many observational studies have shown that the majority of patients do not achieve adequate control by the end of their induction periods and clinical trials, in the real world," with currently available treatments.

Moreover, "there are challenges that come up with any of the different therapies," he said, with adverse effects an important issue. For example, biologic therapies are associated with conjunctivitis, facial erythema, and arthralgia, and there are boxed warnings for Janus kinase inhibitors.

Silverberg continued, "Even patients with a favorable response can experience a loss of disease control when they come off therapy." Consequently, "new strategies are certainly welcome that could potentially induce both deep and potentially therapy-free remission."

To those ends, he explained that regulatory T cells play a central role in immune homeostasis but have not been "therapeutically relevant until very recently," when it was posited that increasing their function can "induce that homeostasis, to normalize the inflammatory cascades" seen in a range of conditions, including atopic dermatitis.

Rezpegaldesleukin has high selectivity for regulatory T cells, without causing activation of effector T cells, and has been shown to increase cell numbers in a dose-dependent manner that is sustained for up to 30 days.

The current study involved patients aged 18-70 years with moderate to severe atopic dermatitis and a history of inadequate responses or intolerance to topical medications, and an EASI score ≥ 16.

Participants were randomly assigned to receive subcutaneous rezpegaldesleukin 12 µg/kg or 24 µg/kg or placebo every 2 weeks for 12 weeks. They then discontinued treatment and were followed up until week 19, when responders, defined as having a reduction in EASI score ≥ 50%, continued follow-up out to week 48.

Seventeen patients were randomized to higher-dose rezpegaldesleukin, whereas 16 received the lower dose and 10 were assigned to placebo. Silverberg said that the three groups were "fairly well balanced," with "fairly good representation" across age, race, and ethnicity groups.

The mean baseline EASI score was between 21.9 and 23.7, and the Validated Investigator Global Assessment for Atopic Dermatitis (vIGA-AD) suggested that there was an even split between moderate and severe atopic dermatitis, although the higher-dose rezpegaldesleukin group had more patients with moderate disease.

By week 12, rezpegaldesleukin was associated with significantly greater improvements in EASI scores vs placebo. Patients on the higher dose had a mean 83% improvement over baseline vs 65% with the lower dose and 47% with placebo (P = .002 for the higher dose vs placebo).

Crucially, these differences were maintained up to week 48 in patients, particularly in the higher-dose group.

There was also a nonsignificant increase in the proportion of patients who achieved a reduction in EASI scores ≥ 75% over baseline with the active drug: 41% at week 12 with higher-dose rezpegaldesleukin, 25% with the lower dose, and 20% with placebo. Again, the benefit was maintained up to week 48.

The mean improvement in BSA score from baseline with rezpegaldesleukin was significantly greater than that seen with placebo, at 72% with the higher dose, 55% with the lower dose, and 36% with placebo (P = .0158 for the higher dose vs placebo).

Although improvements in vIGA-AD scores over baseline with rezpegaldesleukin were not substantial at week 12, by week 48 there was a marked difference between higher-dose rezpegaldesleukin and placebo, with 40.0% of patients responding to the drug vs 0% in the latter group.

A similar pattern was seen for the Itch Numeric Rating Scale, in which 55.6% of patients treated with higher-dose rezpegaldesleukin responding by week 48 compared with 0% of those who received placebo.

Greater improvements in the Dermatology Life Quality Index (DLQI) and Patient Oriented Eczema Measure (POEM) over baseline with higher-dose rezpegaldesleukin vs plain placebo were also noted, despite a strong response in the latter group.

Silverberg reported that all treatment-emergent adverse effects in the two rezpegaldesleukin treatment arms were mild to moderate, with no severe or serious events observed.

The most common adverse events were mild to moderate injection-site reactions, seen in 75.0% of the lower-dose rezpegaldesleukin group and 58.8% the of higher-dose group. There were no cases of conjunctivitis.

The study was sponsored by Eli Lilly and Company in collaboration with Nektar Therapeutics.

Silverberg declares relationships with AbbVie, Alamar, Aldena, Amgen, AOBiome, Arcutis, Arena, Asana, ASLAN, BioMX, Biosion, Bodewell, Boehringer-Ingelheim, Bristol-Myers Squibb, Cara, Castle Biosciences, Celgene, Connect Biopharma, CorEvitas, Dermavant, DermTech, Eli Lilly, Galderma, GlaxoSmithKline, Incyte, Kiniksa, LEO Pharma, Nektar, Novartis, Optum, Pfizer, RAPT, Recludix, Regeneron, Sanofi-Genzyme, Shaperon, Target RWE, Union, and UpToDate.

European Academy of Dermatology and Venereology (EADV) 2023 Annual Meeting: Abstract 6685. Presented October 13, 2023.

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