Oncolytic Virotherapy for Melanoma Brain Metastases, a Potential New Treatment Paradigm?

Oncolytic Virotherapy for High-Grade Glioma and Current Evidence and Factors to Consider for Incorporation into Clinical Practice

Brain tumor incidence is on the rise, and glioblastoma comprises the majority of primary tumors. Despite maximal safe resection and adjuvant chemoradiation, median survival for high-grade glioma remains poor. For this reason, it is important to develop and incorporate new treatment strategies. Oncolytic virotherapy has emerged as a viable new therapeutic entity to fill this gap. Preclinical research has shown oncolytic virotherapy to be a robust and effective treatment option for brain tumors, and clinical trials for both adult and pediatric high-grade glioma are underway. The unique and protected environment of the nervous system, in part due to the blood-brain barrier, prevents traditional systemic therapies from achieving adequate penetration. Brain tumors are also heterogenous in nature due to their diverse molecular profiles, further complicating systemic treatment efforts. Oncolytic viruses may serve to fill this gap in brain tumor treatment given their amenability to genetic modification and ability to target unique tumor epitopes. In addition, direct inoculation of the oncolytic virus agent to the tumor bed following surgical resection absolves risk of systemic side effects and ensures adequate delivery. As virotherapy transitions from bench to bedside, it is important to discuss factors to make this transition more seamless. In this article, we describe the current clinical evidence as it pertains to oncolytic virotherapy and the treatment of brain tumors as well as factors to consider for its incorporation into neurosurgical workflow.

Epidemiology, management, and treatment outcomes of metastatic spinal melanoma

Metastatic spinal melanoma is a rare and aggressive disease process with poor prognosis. We review the literature on metastatic spinal melanoma, focusing on its epidemiology, management, and treatment outcomes. Demographics of metastatic spinal melanoma are similar to those for cutaneous melanoma, and cutaneous primary tumors tend to be most common. Decompressive surgical intervention and radiotherapy have traditionally been considered mainstays of treatment, and stereotactic radiosurgery has emerged as a promising approach in the operative management of metastatic spinal melanoma. While survival outcomes for metastatic spinal melanoma remain poor, they have improved in recent years with the advent of immune checkpoint inhibition, used in conjunction with surgery and radiotherapy. New treatment options remain under investigation, especially for patients with disease refractory to immunotherapy. We additionally explore several of these promising future directions. Nevertheless, further investigation of treatment outcomes, ideally incorporating high-quality prospective data from randomized controlled trials, is needed to identify optimal management of metastatic spinal melanoma.

Geographic disparities in access to immunotherapy clinical trials for metastatic melanoma

Survival outcomes for metastatic melanoma have drastically improved with the advent of immunotherapy. Access to ongoing immunotherapy clinical trials has become increasingly important to patients with advanced disease. We sought to quantify geographic disparities in access to these trials by U.S. division, region, urban/rural status, and median income. We searched ClinicalTrials.gov for interventional immunotherapy trials for metastatic melanoma from 2015 to 2021 and identified U.S. zip codes for each participating trial site. ArcGIS was used to calculate the one-way driving time from each zip code to the nearest treatment center. Melanoma burden in each zip code outside a 60 min driving radius was calculated by multiplying population by the corresponding state's cancer-specific mortality rate. χ² tests were used to test for significance between census regions, divisions, and urban vs. rural zip codes, while logistic regression was used to quantify risk of poor access with median income. Across 148 trials, 4844 treatment centers were located in 1102 unique zip codes. 9010 zip codes were located greater than one-hour driving time from the nearest clinical trial. Southern regions were most likely to have poor access of all regions (p < 0.001), and rural status also significantly correlated with poor access (p < 0.001). For every $10,000 increase in median income, the likelihood of a zip code being within 60 min from a trial increased by 1.315. While immunotherapy continue to improve survival outcomes for metastatic melanoma, geographic access to clinical trials investigating these therapies remains a challenge for a significant proportion of the U.S. population.