Richard Gurgel, MD, MSCI, an associate professor of otolaryngology at the University of Utah in Salt Lake City, said that biologics are an option for pediatric patients with neurofibromatosis type 2 (NF2) when other options are scant. NF2 is an autosomal dominant disease in which tumors grow in the central nervous system, with the hallmark of bilateral vestibular schwannomas. “This is a really aggressive disease, and these patients can get tumors anywhere in their central nervous system,” Dr. Gurgel said. By their 30s and 40s, many people with severe forms of the disease are deaf or blind and have paralysis.
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June 2022Although patients tend to be diagnosed in their mid 20s, the disease typically begins many years before. “It just highlights the fact that NF2 is actually a pediatric illness. We don’t typically think of it that way because we see and care for patients later on in life,” he said. “But if you look at when these patients initially present with their symptoms, almost all are within their teenage years, some even younger than that.”
Because the goal is to maximize function and minimize morbidity, a difficult situation arises when patients have diffuse disease, said Dr. Gurgel.
That’s when treatment with a biologic therapy or targeted molecular therapy becomes a reasonable option. Treatment with bevacizumab, a vascular endothelial growth factor inhibitor, for example, has shown positive, although mixed, results in NF2. While patients often show a positive response with tumor regression, there can also be a plateau during treatment (Childs Nerv Syst. 2020;36:2471-2480). “That’s generally been our experience and what the literature demonstrates for these patients,” Dr. Gurgel said. Patients are treated with 5 to 10 mg/kg every two to three weeks, but hypertension, renal function, bleeding, fatigue, and headache must be monitored.
Other biologics, including tyrosine–kinase inhibitors and mTOR inhibitors, are being investigated with the hope that researchers will find the “magic bullet” to help eliminate these tumors, said Dr. Gurgel. “They’re very difficult tumors to treat.”
Recurrent Respiratory Papillomatosis
Biologics are also part of the toolbox for the treatment of recurrent respiratory papillomatosis (RRP), said Alessandro de Alarcon, MD, MPH, a professor of pediatrics at the University of Cincinnati in Ohio. In this pediatric population, bevacizumab can double the time between surgeries. About a fifth of patients have a complete response, about a fifth have no response, and more than half have a partial response, Dr. de Alarcon said.