Atopic dermatitis: Pivotal dupilumab results create sensation

VIENNA – The marquee event at this year’s annual congress of the European Academy of Dermatology and Venereology – the one everyone was eagerly awaiting – was the first presentation of two large, international, pivotal phase III randomized trials of dupilumab for treatment of inadequately controlled moderate to severe atopic dermatitis in adults.

Attendees at EADV 2016 understood that, if positive, these studies, known as SOLO 1 and SOLO 2, would be transformative. They would herald a new era of highly effective targeted biologic therapy for this common and often debilitating chronic relapsing skin disease, akin to what occurred in psoriasis therapy well over a decade ago.

The results did not disappoint.

Dr. Eric L. Simpson

“Dual targeting of interleukin-4 and -13 represents a therapeutic option for patients with moderate to severe atopic dermatitis,” added Dr. Simpson, professor of dermatology at Oregon Health and Science University, Portland.

These results have implications extending beyond atopic dermatitis. Asthma, chronic sinusitis with nasal polyposis, and eosinophilic esophagitis are other conditions where the type 2 inflammatory cytokines IL-4 and -13 are believed to be important drivers of disease activity. Clinical trials of dupilumab in those diseases are underway.

Dupilumab, a fully human monoclonal antibody that binds specifically to the shared alpha chain subunit of the IL-4 and -13 receptors, hit all of its primary and secondary outcome measures in SOLO 1 and SOLO 2. Moreover, some of these “secondary” endpoints are consistently reported in patient surveys to be among what they consider to be the most troublesome aspects of atopic dermatitis, including intense itching, disrupted sleep, clinically significant anxiety and/or depression, and generally diminished quality of life.

SOLO 1 and SOLO 2 were identically designed, independent, randomized, double-blind, placebo-controlled clinical trials of 16 weeks’ duration. Conducted in North America, Europe, and Asia, they included a total of 1,379 patients, split roughly 50/50 between those with moderate or severe atopic dermatitis. Their average disease duration was 26 years. Participants were randomized to subcutaneous injection of dupilumab at 300 mg once weekly or every 2 weeks or to matching placebo.

The primary endpoint was a score of clear or almost clear – 0 or 1 – on the Investigator’s Global Assessment (IGA) at week 16 accompanied by a reduction of at least 2 points from baseline. A key secondary endpoint was at least a 75% improvement in the Eczema Area and Severity Index (EASI-75), considered a coprimary endpoint by regulators in Japan and the European Union.

The use of topical agents for atopic dermatitis was not permitted except as rescue therapy for uncontrolled symptoms. An IGA of 0 or 1 with at least a 2-point drop from baseline was a high bar to reach, given that a median of 50% of participants’ body surface area was affected. But in SOLO 1, that target was achieved in 37.9% of subjects on dupilumab every other week, 37.2% with weekly therapy, and just 10.3% of placebo-treated controls. Similarly, in SOLO 2, the rates were 36.1%, 36.4%, and 8.5%, respectively.

Of note, there were essentially no differences in outcomes across the board with weekly versus biweekly dosing of dupilumab.

From a median baseline EASI score of 30, an EASI-75 was achieved at 16 weeks in 51.3% of patients on dupilumab every other week, 52.5% on weekly injections, and 14.7% of controls in SOLO 1. In SOLO 2, the corresponding EASI-75 rates were 44.2%, 48.1%, and 11.9%, respectively.

Itch is described by most patients with moderate to severe atopic dermatitis as their No. 1 issue. From a baseline median peak score of 7.7 on a 0-10 numerical rating scale for pruritus, week 16 scores dropped by a median of 51% in patients on dupilumab every 2 weeks, 48.9% with weekly therapy, and 26.1% with placebo in SOLO 1. Results in SOLO 2 mirrored those in SOLO 1.

Particularly noteworthy was the finding that a significant reduction in itch severity was documented by week 2 in both dupilumab treatment arms, Dr. Simpson observed.

Just under half of study participants had a baseline score of 8 or more on the Hospital Anxiety and Depression Scale Anxiety subscale or HADS Depression subscale, considered the cutoff for a clinically significant mood disorder. Among affected patients, a score of less than 8 was achieved at 16 weeks without the use of psychotropic medications in 12.4% of SOLO 1 participants on placebo, 41% on biweekly dupilumab, and 36.3% with weekly dupilumab. In SOLO 2, the rates were 6.1% with placebo, 39.5% with biweekly dupilumab, and 41.2% with once-weekly dupilumab.

The median baseline Dermatology Life Quality Index score was 15 across the two parallel trials. The collective proportion of patients who experienced at least a 4-point improvement, which is considered a clinically meaningful response, was 29.1% in controls, compared with 68.6% in patients dupilumab every other week and 60.2% with weekly dupilumab.

On the Patient-Oriented Eczema Measure, a composite yardstick that emphasizes sleep symptoms, the median baseline score was 22 out of a possible 28. An improvement of 4 points or more, defined as a minimal clinically important difference, was achieved in a collective 25.6% of controls, 69.6% of patients on biweekly dupilumab, and 63.6% on weekly dupilumab.

Regarding safety, no increase in infections was seen with dupilumab. In fact, only two adverse events were more frequent than with placebo. One was injection-site reactions, which were two- to threefold more common than in controls, and all of which were mild to moderate. The other safety issue was conjunctivitis, which occurred in three patients in the control arms of SOLO 1 and 2, compared with 36 in the dupilumab arms.

Asked about the mechanism of this conjunctivitis, Dr. Simpson said it remains unknown. There was no signal of an issue in the phase II studies.

“Ongoing studies are attempting to further characterize the affected patients. I would say the comforting thing is that most cases have been mild to moderate and have responded to topical steroids or topical cyclosporine. Only one patient had to discontinue dupilumab,” according to the dermatologist.

In any event, 16 weeks of treatment is not sufficient to determine the safety of long-term therapy. Long-term extension studies of SOLO 1 and 2 are well underway, as are earlier stage clinical trials in pediatric patients with moderate to severe atopic dermatitis.

In response to another audience question, Dr. Simpson said he and his coinvestigators plan to drill down into the data to see if patients with severe atopic dermatitis obtained significantly more benefits from weekly as compared with biweekly therapy, or if treatment every 2 weeks was as good as weekly therapy across the board. It’s an important question, but the study finished so recently that the investigators haven’t yet had time to conduct the analysis.

The pivotal phase III dupilumab findings met with an enthusiastic reception.

“Biologic therapy for atopic dermatitis is the light at the end of the tunnel,” declared session cochair Lajos Kemény, MD, professor and chairman of the department of dermatology and allergology at the University of Szeged, Hungary.

“Seminal work,” commented David M. Pariser, MD, professor of dermatology at Eastern Virginia Medical School in Norfolk.

Dr. Simpson’s presentation of the pivotal dupilumab studies was but one of the highlights of a horn-of-plenty late-breaking clinical trials session held on the final full day of EADV 2016. As attendees mingled in the hall afterward, a palpable sense of pride in their profession was evident. It was borne of the knowledge that their field not only includes basic and translational scientists capable of unraveling the inflammatory pathways involved in a challenging disease like atopic dermatitis, where there is a long-standing unmet need for new therapies, but also that their specialty includes experienced clinical trialists who can put those novel targeted therapies to the test.

There was also a sense of satisfaction that, although dermatology is a small specialty, these accomplishments are drawing favorable attention throughout the broader medical community. Pivotal trials of novel treatments for important dermatologic diseases are regularly getting published in prominent nondermatology journals. For instance, simultaneous with Dr. Simpson’s presentation in Vienna at EADV 2016, the SOLO 1 and 2 results were published online in the New England Journal of Medicine (doi. 10.1056/NEJMoa1610020).

“The online publication occurred a few minutes ago, at the start of my presentation. I didn’t say anything then because I didn’t want everybody looking at their cell phones,” he quipped.

The Food and Drug Administration has granted dupilumab a breakthrough therapy designation; a decision on the application for approval is expected by March 29, 2017.

The phase III dupilumab trials were funded by Sanofi and Regeneron Pharmaceuticals. Dr. Simpson reported having received research grants from and serving as a consultant to Regeneron and more than a dozen other pharmaceutical companies.