Anadkat, Milan J.

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.

Abstract Background The results of a previous phase IIa trial suggested efficacy of the anti-C5a compound vilobelimab in a small number of patients with severe hidradenitis suppurativa (HS) refractory to adalimumab treatment. Objectives To study the efficacy of vilobelimab in a larger-scale randomized phase IIb trial (SHINE) of patients with moderate-to-severe HS. Methods In total, 177 patients with moderate-to-severe HS were treated either with placebo or one of four doses of vilobelimab, a monoclonal antibody that targets the complement split product C5a. Hidradenitis Suppurativa Clinical Response (HiSCR) at 16 weeks was the primary endpoint. Those who achieved HiSCR switched to open-label low-dose vilobelimab; those who did not were switched to medium-dose vilobelimab. The trial was registered with the EU Clinical Trials Register (EudraCT number 2017-004501-40) and ClinicalTrials.gov (NCT03487276). Results The study did not meet the primary endpoint, perhaps due, in part, to an unexpectedly high HiSCR placebo response rate of 47.1%. HS flares decreased and post hoc analysis showed that high-dose vilobelimab significantly decreased the median draining tunnel counts and IHS4 score by 63%. Following the switch to medium-dose vilobelimab at week 16, 45.5% of those who did not respond to treatment achieved HiSCR at week 40. Conclusions Compared with placebo, vilobelimab treatment did not result in significant HiSCR improvements in patients with moderate-to-severe HS. Post hoc analysis revealed significant effects for the highest tested dose on draining tunnel reduction and IHS4 score, which captures reductions in draining tunnels. These findings warrant further investigation.

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.