PracticeUpdate Conference Series World Congress of Dermatology 2019

Xolma Study Suggests Omalizumab May Play Role in Treatment of Cutaneous Mastocytosis But the findings were nonsignificant due to a very small study sample size.

T here is some suggestion froma small randomized trial that omalizumab may prove beneficial for the treatment of cutaneous mastocytosis, but the study sample was simply too small to allow for any firm conclusions to be drawn. “When we look at mastocytosis patients from a der- matological point of view, there are a lot of different types,” Julia-Tatjana Maul, MD, of University Hospital of Zurich in Switzerland, said during her presentation, which was attended by Elsevier’s PracticeUpdate . “There is solitary mastocytosis, plaque mastocytosis, diffuse cutaneous, and telangiectatic. … [Manifestations of the disease include] skin lesions [as well as] general symptoms, like dizziness, musculoskeletal problems, gastrointestinal [issues], differences in blood levels, as well as cardiovascular problems.” Omalizumab is a humanized IgG1k monoclonal anti-IgE antibody that binds to circulating free IgE. There have been case reports in the literature of omalizumab being an effective treatment for masto- cytosis, but no clinical trials have yet been conducted, explained Dr. Maul. In addition, there is reason to believe omalizumab could interfere with the patho- genesis of mastocytosis, because IgE molecules

have been shown to bind to the high-affinity IgE receptor FcεRI on mastocytes. For the Xolma trial, the safety and efficacy of omal- izumab was investigated among 17 patients with various forms of mastocytosis in a multicenter, pro- spective double-blind placebo-controlled trial. In total, 7 patients were randomized to the omalizumab group and 9 to placebo. Omalizumab was dosed according to total serum IgE and body weight, as it is dosed for use in allergic asthma. One patient in each arm of the trial dropped out before treatment was initiated. In addition, one patient in the omalizumab arm discontinued treat- ment at visit 6, and one patient in the placebo arm discontinued treatment at visit 3. This left 6 patients in the active therapy arm and 8 patients in the placebo arm for the intent-to-treat analysis as well as 5 and 7 patients, respectively, for the per-protocol analysis. The primary endpoint of the trial was improvement in Association Française pour les Initiatives de Recherche sur le Mastocyte et les Mastocytoses (AFIRMM) score at 6 months. This score has been developed by a French association that specializes in mastocytes and mastocytosis and encompasses a wide range of signs and symptoms of mastocytosis. Secondary endpoints included changes in AFIRMM score at the end of the study as well as improve- ments in number of allergic reactions, changes in a visual analog rating scale for major events, pres- sure-induced wheal and flare, and frequency of use of medications for mastocytosis, including antihista- mines and cromoglycates. In the intent-to-treat analysis, after 6 months, median AFIRMM score improved from 104.0 to 102.0 in the

" [The findings are] limited due to the small study sample, as it was very difficult to find patients with cutaneous mastocytosis who fit the [study] criteria, … [but] we did see that the symptoms of mastocytosis were improved. "

PRACTICEUPDATE CONFERENCE SERIES • WCD 2019 18