A study of and continued evidence of efficacy for up to 52 weeks, reported the authors of the study, published online Oct. 9 in the British Journal of Dermatology.
The phase 2a open-label, ascending-dose cohort study of dupilumab in 40 adolescents with moderate to severe AD was followed by a 48-week phase 3 open-label extension study in 36 of those participants. Dupilumab is a monoclonal antibody that inhibits signaling of interleukin (IL)-4 and IL-13.
In the phase 2a study, participants were treated with a single subcutaneous dose of dupilumab – either 2 mg/kg or 4 mg/kg – and had 8 weeks of pharmacokinetic sampling. They subsequently received that same dose weekly for 4 weeks, with an 8-week-long safety follow-up period. Those who participated in the open-label extension continued their weekly dose to a maximum of 300 mg. per kg
The most common treatment-emergent adverse events (a primary endpoint) seen in both the phase 2a and phase 3 studies were nasopharyngitis and exacerbation of AD – in the phase 2a study, exacerbations were seen in the period when patients weren’t taking the treatment. In the 2-mg and 4-mg groups, the incidence of skin infections was 29% and 42%, respectively, and the incidence of injection site reactions – which were mostly mild – were 18% and 11%, respectively. Researchers also noted conjunctivitis in 18% and 16% of the patients in the 2-mg and 4-mg groups, respectively, but none of the cases were considered serious and all resolved over the course of the study. In the phase 2a study, 50% of patients on the 2-mg/kg dose and 65% of those on the 4-mg/kg dose experienced an adverse event, while in the open-label extension all reported at least one adverse event.
There was one case of suicidal behavior and one case of systemic or severe hypersensitivity reported in the 2-mg/kg groups, both of which were considered adverse events of special interest. There were no deaths.
However none of the serious adverse events – which included infected AD, palpitations, patent ductus arteriosus, and food allergy – were linked to the study treatment, and no adverse events led to study discontinuation, the authors reported.
By week 12, 70% of participants in the 2-mg/kg group and 75% in the 4-mg/kg group had achieved a 50% or greater improvement in their Eczema Area and Severity Index (EASI) scores, which was a secondary outcome. By week 52, that had increased to 100% and 89% respectively.
More than half the patients (55%) in the 2-mg/kg group, and 40% of those in the 4-mg/kg group achieved a 75% or more improvement in their EASI scores by week 12, which increased to 88% and 78%, respectively, by week 52 in the open label phase.
“The results from these studies support use of dupilumab for the long-term management of moderate to severe AD in adolescents,” wrote Michael J. Cork, MD, professor of dermatology, University of Sheffield, England, and coauthors. No new safety signals were identified, “compared with the known safety profile of dupilumab in adults with moderate to severe AD,” and “the PK profile was characterized by nonlinear, target-mediated kinetics, consistent with the profile in adults with moderate to severe AD,” they added.
Dupilumab was approved in the United States in March 2019 for adolescents with moderate to severe AD whose disease is not adequately controlled with topical prescription therapies or when those therapies are not advisable.
The study was sponsored by dupilumab manufacturers Sanofi and Regeneron Pharmaceuticals, which market dupilumab as Dupixent in the United States. Dr. Cork disclosures included those related to Sanofi Genzyme and Regeneron; other authors included employees of the companies.
SOURCE: Cork M et al. Br J Dermatol. 2019 Oct 9. doi: 10.1111/bjd.18476.