A Case of Sustained Objective Response of Recurrent/Progressive Diffuse Intrinsic Pontine Glioma with Phenylbutyrate and Targeted Agents

Abstract

Diffuse intrinsic pontine glioma (DIPG) is the most common type of brainstem glioma and one of the most deadly brain tumors. DIPG in young adult patients is a rare disease for which treatment options are limited. Radiation therapy remains the standard-of-care for newly-diagnosed DIPG, but no established therapies for recurrent disease are available. This paper describes the results of treatment of a young adult patient diagnosed with DIPG that progressed after radiation therapy. Therapy included sodium phenylbutyrate (PB) in combination with the targeted agents: pazopanib, everolimus, erlotinib, and bevacizumab. The patient achieved a rapid partial response, which persisted over a year and five months. The patient opted to discontinue the therapy and thereafter elected chemotherapy, which resulted in a subsequent rapid progression and death within one month. The targeted treatment was associated with minor toxicity that included a Grade 2 skin rash and Grade 1 elevation of transaminases. In conclusion, a combination of PB and currently available targeted drugs may offer extended survival in patients with recurrent DIPG.