Characterization and management of dermatologic adverse events with the NovoTTF-100A System, a novel anti-mitotic electric field device for the treatment of recurrent glioblastoma

Abstract

The NovoTTF-100A System (NovoTTF™ Therapy, Novocure Inc.) is a device that delivers alternating electric fields (TTFields) to tumor cells and interferes with mitosis. It is approved for use as monotherapy for the treatment of recurrent glioblastoma (rGB). TTFields are delivered through insulated transducer arrays applied onto the shaved scalp and connected to a battery-operated field generator. The occurrence of dermatologic adverse events (dAEs) is primarily due to the continuous contact between the array-related components and the scalp for periods of 3-4 days (together with other risk factors). These dAEs may include allergic and irritant dermatitis, mechanical lesions, ulcers, and skin infection. The incidence of dAEs in the phase III trial (n = 116) was 16% (2% grade 2, 0% grade 3/4); the post-marketing surveillance program (n = 570) revealed 156 (21.8%) dAEs with some patients reporting more than one event. Prophylactic strategies for dAEs include proper shaving and cleansing of the scalp and array relocation. Treatment-based strategies are AE-specific and include topical or oral antibiotics, topical corticosteroids, and isolation of affected skin areas from adhesives and pressure. The addition of skin care strategies to the NovoTTF-100A System use will maximize adherence to therapy while maintaining quality of life, all of which contribute to the therapeutic benefit of NovoTTF Therapy in rGB.