Severe mucopolysaccharidosis type II (MPS-II) patients present with progressive mental impairment and reduced life expectancy. While current available treatment cannot cross the blood–brain barrier, the enzyme replacement therapy with pabinafusp alfa (a recombinant iduronate-2-sulfatase fused to an antihuman transferrin receptor antibody) was designed to penetrate it using transferrin receptor-mediated transcytosis. In this cross-sectional retrospective study, we aimed to report the impact of this new therapy using patient-reported outcomes. Data were collected using standardized questionnaire replied by patients or their caregivers (as proxies). Nine patients received intravenous administration of pabinafusp alfa for at least 104 weeks. All patient showed improvements in behavior (mainly aggressiveness), speech, motor ability, muscle strength, facial expression, breathing, and cognitive skills. Gait improvement was also found in 78% of participants. Caregivers also reported improvements in emotion demonstration as ability to smile, establish eye contact, and give hugs. Collectively, our results indicate a positive impact of pabinafusp alfa on quality of life of individuals with MPS-II and their relatives/caregivers. Future studies are warranted to elucidate the mechanisms underlying these beneficial effects.

All procedures followed were in accordance with the ethical standards of the responsible committee on human experimentation (institutional and national) and with the Declaration of Helsinki 2013, as revised in 2000. The Ethics Committee from the Universidade Federal de São Paulo approved the study under the #0613/2018 protocol. Written informed consent for publication were obtained from the patients or the legal responsible of the patients.

This article does not contain any studies with animal subjects performed by any of the authors.

A.M.M., M.A.C., C.C.M., and E.T.S. conceived and designed the manuscript and conducted data collection and analysis. All authors revised the text critically and approved the final manuscript.

Received: 16 April 2023

Accepted: 04 December 2023

Article published online:
01 March 2024

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