Paul Harmatz, MD, on Reducing GAGs in MPS Type 2 With RGX-121 Gene Therapy

“The highest dose now is the dose that will go forward in a phase 3 trial and shows an ability to decrease these storage biomarkers to near normal range, with an over 80% reduction and below the level we would see in an attenuated patient without neurocognitive disease. The effectiveness, at least at this point, is documented up to 48 weeks, and we're still collecting final data up to 104 weeks, at which point will end the phase 1/2 study once all 15 patients reach that time point.”

Participants with neuronopathic mucopolysaccharidosis type 2 (MPS2) treated with an image-guided injection of RGX-121 gene therapy (REGENXBIO) to the cisterna magna in the phase 1/2 CAMPSIITE trial (NCT03566043) experienced dose-dependent reductions in cerebrospinal fluid glycosaminoglycans including D2S6.

Updated data from CAMPSIITE were presented at the American Society of Gene and Cell Therapy (ASGCT) 2023 Annual Meeting, held May 16-20, in Los Angeles, California, by Paul Harmatz, MD, pediatric gastroenterologist and professor in residence, University of California at San Francisco. CGTLive spoke with Harmatz to learn more about the current treatment landscape of MPS2, unmet needs that remain, and how RGX-121 may potentially address these unmet needs. He discussed positive results seen so far, including a manageable safety profile and reduction of disease significant biomarkers. He noted that the phase 3 study is now enrolling and encouraged clinicians and families to look into the trial.

REFERENCE

Harmatz P, Ficicioglu C, Giugliani R, et al. RGX-121 gene therapy for the treatment of neuronopathic mucopolysaccharidosis type II (MPS II): Interim analysis of data from the first in human study. Presented at: ASGCT 2023 Annual Meeting; May 16-20; Los Angeles, California. Poster #807