Boull, Christina

Background Neurofibromatosis type 1 (NF1) is a genetic disorder in which plexiform neurofibromas (PNs) develop in approximately 30% to 50% of affected individuals, often causing substantial morbidity. Treatment of NF1-associated PNs is challenging due to disease variability and tumor complexity. Observations In the Phase 2b ReNeu trial (NCT03962543), mirdametinib, a mitogen-activated protein kinase kinase 1/2 (MEK) inhibitor, demonstrated efficacy and a manageable safety profile in children and adults with symptomatic PNs, achieving confirmed objective responses in 52% of children and 41% of adults, with substantial reductions in target tumor PN volume and improvements in patient- and parent proxy-reported outcomes. However, dermatologic adverse events (AEs) are common with MEK inhibitors, including mirdametinib, and can impact adherence and quality of life. While the ReNeu protocol included supportive care considerations for skin reactions associated with mirdametinib, some investigators recognized a need for more detailed guidance. The ReNeu Scientific Steering Committee, in collaboration with oncology and oncodermatology experts, developed expert-driven recommendations for the proactive management of mirdametinib-related skin AEs. Conclusions These strategies emphasize early recognition, individualized care, and timely intervention to help reduce the severity of mirdametinib-related skin AEs, minimize dose modifications, and support treatment continuity and long-term treatment goals. Although these recommendations were specifically developed for mirdametinib based on ReNeu trial experience, they may also provide practical guidance for managing skin AEs associated with other MEK inhibitors in clinical practice.

Atopic dermatitis affects 20% to 25% of children and has significant impact on quality of life of patients and families. Recent studies of the pathogenesis of AD highlight the interplay between a defective skin barrier, immune dysfunction, and the cutaneous microbiome. Standard of care for AD treatment includes topical corticosteroids for active disease and moisturization to repair the barrier defect. Emerging treatments include dupilumab and Janus kinase (JAK) inhibitors. Reduction of triggers and proactive treatment with topical corticosteroids and/or topical calcineurin inhibitors can reduce flares. Treatment plans should be clear and as simple as possible to maximize adherence.

Abstract ReNeu (NCT03962543) is a trial of the investigational, oral, selective MEK1/2 inhibitor (MEKi) mirdametinib in adults (≥18 years) and children (2-17 years) with NF1-PN. Skin adverse events (AEs) were common in ReNeu, and some discontinuations were noted with low-grade AEs. A multidisciplinary team retrospectively reviewed skincare practices at one high-enrolling site (n=12) with no discontinuations due to skin AEs; these were incorporated into ReNeu trial recommendations and recently updated. The purpose was to prevent/manage skin AEs and maintain protocol treatment adherence. MEKi skin AEs vary by pubertal status, therefore recommendations also vary by pubertal status. All patients were counseled to adopt hygienic skincare practices, including bathing daily, and using mild cleansers and hypoallergenic skin moisturizers (cream or ointment-based emollient; minimum BID) to prevent dry skin. Prepubescent patients were advised to incorporate diluted bleach baths (3-4 times/week) when initiating mirdametinib or after rash development. Treatments recommended for mild-to-severe dermatitis were hydrocortisone cream (2.5% BID) on face/skinfold areas and triamcinolone ointment (0.1% BID) on trunk/extremities. Treatments for mild acneiform eruptions included topical clindamycin lotion (1.0% BID) until resolution, with optional hydrocortisone cream (2.5% BID). For moderate-to-severe acneiform eruptions, cephalexin (20 mg/kg/day divided BID, max 500 mg, ≤6 weeks), amoxicillin (25 mg/kg/day divided BID, max 875 mg, ≤6 weeks), or oral fluconazole (20 mg/kg/day, max 100 mg, 5 days then once weekly for 3 months) were suggested. Postpubescent patients were advised to initiate topical 1.0% clindamycin lotion and oral doxycycline or minocycline (50-mg daily, 3 months) with mirdametinib initiation. Patients with subsequent mild-to-severe acneiform eruptions were advised to apply hydrocortisone cream (2.5% BID) or triamcinolone ointment (0.1% BID). Referral to a dermatologist was suggested for all patients with uncontrolled dermatitis, worsening acneiform eruptions, or infection. Proactive skincare practices appeared effective at this site, but prospective validation is necessary before making clinical recommendations.

AbstractBackgroundSystemic sirolimus (rapamycin) has recently been found effective in treating complex vascular anomalies by reducing the size and associated complications. Many vascular anomalies have a cutaneous component, and thus, we sought to determine whether topical administration of sirolimus may be an effective therapy, as data on the use of topical sirolimus are limited.ObjectiveWe reviewed the efficacy and tolerability of topical formulations of sirolimus in the treatment of various simple and combined vascular malformations and tumors.MethodsEighteen patients with any vascular anomaly treated exclusively with topical sirolimus were retrospectively reviewed.ResultsEleven patients had combined venous lymphatic malformations, three had tufted angiomas, two had a lymphatic malformation, one had a venous malformation, and one had a verrucous venous malformation. All (100%) patients reported some degree of improvement and 50% of patients reported marked improvement in one or more symptoms, most commonly blebs and lymphatic drainage, and bleeding.LimitationsThe retrospective nature, small number of patients, and differences in topical preparations limit the broad application of the results.ConclusionTopical sirolimus appears to be a safe and useful non‐invasive therapy that is well‐tolerated in the treatment of the cutaneous portion of a variety of vascular anomalies.

AbstractPemphigus herpetiformis (PH) is characterized by grouped vesicular or papular pruritic lesions with histologic and immunopathologic features of pemphigus. PH can manifest at any age, and paraneoplastic cases have been reported. We describe a healthy boy born with acral crateriform erosions of the hands and feet whose 35‐year‐old mother had similar lesions. Biopsies from both patients were most consistent with PH. The mother was diagnosed with high‐grade B‐cell non‐Hodgkin lymphoma and began chemotherapy with dexamethasone, and her lesions quickly improved. The infant had no additional lesions after 3 weeks of age and his acral erosions healed. To our knowledge, this is the first report of a diagnosis of PH in an infant and the first case of transplacental transmission of PH. This is also the first report of paraneoplastic PH in lymphoma. This case adds to the growing differential diagnosis of skin disease in postpartum women and their neonates.