Exploring Novel Applications: Repositioning Clinically Approved Therapies for Medulloblastoma Treatment

The advent of tyrosine kinase inhibitors (TKI), therapeutic antibodies and inducers of apoptosis has revolutionized cancer treatment, yet their application in pediatric tumors, particularly medulloblastoma, remains understudied. Understanding the expression of these targets in specific genetic subgroups could unveil potential repositioning opportunities for already approved drugs.

We analyzed RNA-sequencing data from the R2 Genomics Analysis and Visualization Platform (N = 763 patients, multiple cohorts) and the TCGA database (six individual cohorts 828 patients) to assess the expression of 73 potential targets of TKIs and antibodies targeting immune checkpoint inhibitors (ICI) or membrane receptors and inducers of apoptosis. These treatments, FDA-approved or in phase II clinical trials for solid or hematologic cancers, and their targets were evaluated in both non-metastatic and metastatic patients when data was available. Additionally, we examined treatments tailored to mutated targets crucial for tumorigenesis or resistance to conventional therapies.

Overexpression of certain targets beyond predefined cutoff values in Kaplan-Meier analyses correlated with either prolonged or shortened overall survival. Targets associated with shorter survival suggested potentially relevant treatments, thereby highlighting the importance of defining specific treatments for distinct genetic subgroups. Notably, certain immune checkpoint inhibitors showed relevance for specific subgroups but detriment for others. As a positive control, our analysis confirmed the use of axitinib, an anti-angiogenic treatment, as demonstrated by our recent publication. Surprisingly, a treatment developed for hematological tumors, venetoclax, demonstrated potential efficacy in medulloblastoma.

Medulloblastoma displays subtype-specific expressions of FDA-approved TKI, ICI and pro-apoptotic drug targets, impacting overall survival. Clinical trials investigating these approved treatments in medulloblastoma are therefore warranted.