Omalizumab May Be Effective, Safe for RDEB With High IgE Levels
Omalizumab — an antibody against immunoglobulin E (IgE) — may be effective and safe for wound healing in patients with recessive dystrophic epidermolysis bullosa (RDEB) and high IgE levels, a small study suggests.
The treatment was also safe and well-tolerated, suggesting it may provide a therapeutic alternative for a disease with no “consistently effective” therapies, the scientists wrote.
The study, “The clinical efficacy and safety of anti-IgE therapy in recessive dystrophic epidermolysis bullosa,” was published in Clinical Genetics by a team of researchers in China.
IgE is a type of antibody produced by the immune system in response to allergens or parasites like worms. High IgE levels have been reported in some patients with RDEB, suggesting that it might represent a therapeutic target.
“Omalizumab is an anti-IgE monoclonal antibody,” the researchers wrote, so “it may possibly benefit RDEB patients with elevated IgE levels.”
Sold under the brand name Xolair by Novartis, omalizumab is approved as a treatment for allergic asthma (asthma caused by a reaction to allergens), nasal polyps (soft growths inside the nose), and chronic hives of unknown cause. It works by preventing IgE from binding to and activating certain immune cells, called mast cells and basophils, which play a role in the response to allergens and the protection against parasites.
This study included 12 patients with RDEB: six with severe, four with intermediate, and two with pruriginosa (itchy) RDEB. Eleven patients with high IgE levels received anti-IgE therapy with omalizumab. Their median age was 27.7 years, ranging from 8 to 45.
The higher the IgE levels, the higher the number of inflammatory cells in the skin and the greater the disease activity — as measured using the Birmingham Epidermolysis Bullosa Severity (BEBS) score.
Specifically, these 11 patients received 150 mg of omalizumab per site of injection, under the skin, every four weeks (about one month) for at least three treatment cycles. The initial dosage was the same as used in the treatment of allergic asthma.
One patient stopped treatment after the third cycle due to a poor response.
The remaining 10 patients showed a good response, starting as early as within the first month of treatment, with improved wound healing, especially in chronic open wounds that had not healed in more than six months for three of the participants.
After the last treatment cycle, the BEBS score was reduced by 15%, body surface area (BSA) covered by wounds was reduced by 23%, and pruritus (itching) was decreased by 42%.
The Dermatology Life Quality Index (DLQI) — a questionnaire designed to measure health-related quality of life of patients with a skin disorder — was also improved (lower values).
In the two patients with pruriginosa RDEB, omalizumab also helped flatten plaques (raised areas on the skin) and bullae (fluid-filled blisters) in the elbows, knees, and shins.
Results also showed a reduction of inflammation, as seen by fewer inflammatory cells in the dermis — the layer of skin beneath the epidermis.
After a two-month follow-up period, there were no reports of increased blistering.
Treatment with omalizumab not only reduced skin IgE levels, it also restored the production of type VII collagen protein — a major component of the connective tissue that gives structure and support to tissues and organs, including the skin. This collagen protein is faulty or absent in patients with RDEB, making the skin fragile and prone to blisters.
These findings indicate that “IgE plays a role in skin inflammation, such as erythema [reddening of the skin], inflammatory cell infiltration and pruritus, in patients with RDEB,” the researchers wrote.
IgE levels in the skin matched those in the blood serum, meaning that taking a blood sample could be used “to some extent to determine whether the patient is suitable for anti-IgE treatment and to predict the treatment effect,” they added.
Limitations for this study included its small number of patients and the lack of a control group, the investigators said.