Convection-Enhanced Delivery of Enhancer of Zeste Homolog-2 (EZH2) Inhibitor for the Treatment of Diffuse Intrinsic Pontine Glioma.

Abstract

BACKGROUND:

Diffuse intrinsic pontine glioma (DIPG) is a fatal childhood brain tumor and the majority of patients die within 2 yr after initial diagnosis. Factors that contribute to the dismal prognosis of these patients include the infiltrative nature and anatomic location in an eloquent area of the brain, which precludes total surgical resection, and the presence of the blood-brain barrier (BBB), which reduces the distribution of systemically administered agents. Convection-enhanced delivery (CED) is a direct infusion technique to deliver therapeutic agents into a target site in the brain and able to deliver a high concentration drug to the infusion site without systemic toxicities.

OBJECTIVE:

To assess the efficacy of enhancer of zeste homolog-2 (EZH2) inhibitor by CED against human DIPG xenograft models.

METHODS:

The concentration of EZH2 inhibitor (EPZ-6438) in the brainstem tumor was evaluated by liquid chromatography-mass spectrometry (LC/MS). We treated mice-bearing human DIPG xenografts with EPZ-6438 using systemic (intraperitoneal) or CED administration. Intracranial tumor growth was monitored by bioluminescence image, and the therapeutic response was evaluated by animal survival.

RESULTS:

LC/MS analysis showed that the concentration of EPZ-6438 in the brainstem tumor was 3.74% of serum concentration after systemic administration. CED of EPZ-6438 suppressed tumor growth and significantly extended animal survival when compared to systemic administration of EPZ-6438 (P = .0475).

CONCLUSION:

Our results indicate that CED of an EZH2 inhibitor is a promising strategy to bypass the BBB and to increase the efficacy of an EZH2 inhibitor for the treatment of DIPG.

• Authors: Takahiro Sasaki, Hiroaki Katagi, Stewart Goldman, Oren J Becher, Rintaro Hashizume
• Journal: Neurosurgery (Neurosurgery) Vol. 87 Issue 6 Pg. E680-E688 (11 16 2020) ISSN: 1524-4040 [Electronic] United States
• PMID: 32674144 (Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2020 by the Congress of Neurological Surgeons.

Chemical References

• EZH2 protein, human
• Enhancer of Zeste Homolog 2 Protein

Topics

• Animals
• Brain Stem Neoplasms (drug therapy)
• Convection
• Diffuse Intrinsic Pontine Glioma (drug therapy)
• Enhancer of Zeste Homolog 2 Protein (antagonists & inhibitors)
• Humans
• Mice
• Xenograft Model Antitumor Assays