Study Assesses Caregiver Views to Guide Future Clinical Trial Outcomes

Marisa Wexler, MS avatar

by Marisa Wexler, MS |

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Communication challenges and mobility difficulties are among the most impactful symptoms for children with Sanfilippo syndrome, caregivers reported in a study.

Results from the study, which was funded by the Cure Sanfilippo Foundation, could be used to inform outcome measures in clinical trials for potential treatments.

The study, “Caregivers’ assessment of meaningful and relevant clinical outcome assessments for Sanfilippo syndrome,” was published in the Journal of Patient-Reported Outcomes

Clinical trials are the gold standard for determining if a potential therapy is effective. One of the most important aspects of clinical trial design is defining how the effect of treatment will be measured — for example, finding standardized tests to measure changes in symptom severity.

Sanfilippo syndrome can result in a wide array of symptoms, including behavioral differences, communication challenges, digestive issues, trouble sleeping, and chronic pain. As researchers work to develop treatments for Sanfilippo, it will be useful to know which of these symptoms impact patients the most. That way, they can measure the effects of treatment that are most likely to matter for the people being treated.

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To identify symptoms in a disease that have the most effect, researchers would typically ask patients themselves, but this isn’t practical for Sanfilippo since it affects children and causes cognitive and communication difficulties. Here, researchers talked to caregivers of children with Sanfilippo syndrome to learn more.

The scientists conducted an online focus group attended by 11 mothers of children with Sanfilippo syndrome before having one-on-one interviews with 19 parents of children with the condition. All of the parents interviewed resided in the U.S., and nearly all were white.

In the focus group and interviews, the researchers and parents discussed the impacts of symptoms, broadly grouped into eight categories: communication, eating, sleep, mobility, pain, behavior, adapting, and self-care. Caregivers generally reported that all of these symptoms caused difficulty in their child’s life.

“Overall, our data support the importance of diverse symptom domains that extend beyond cognitive. Participants reported that all of the symptom domains included in the study represented meaningful areas of high impact and unmet treatment need,” the researchers wrote.

The symptoms that caregivers generally said had the highest impact were communication problems and mobility difficulties, followed by pain and sleep problems. The parents viewed adapting, behavior, and eating/swallowing as meaningful, but had relatively lower impact, the researchers wrote.

“The progressive nature of Sanfilippo syndrome resulted in some symptoms being more impactful at different times in disease progression,” they said.

The caregivers also gave their opinions on a number of clinical outcome assessments (COAs), standardized tests used to measure some of these symptoms. A few of these measures were well regarded by the patients, including one of communication called the Vineland Adaptive Behavior Scales-3 Parent/Caregiver Form: Listening and Understanding, and an assessment of eating problems called the Child Oral and Motor Proficiency Scale (ChOMPS).

The Children’s Sleep Habits Questionnaire (CSHQ) and Non-Communicating Child’s Pain Checklist-Revised (NCCPC-R), which assess sleep and pain respectively, also were generally well regarded by the caregivers as accurately reflecting how these symptoms may be experienced by children with Sanfilippo syndrome.

“While the selection of assessments utilized in a clinical trial depends on a range of factors that extend beyond caregiver preferences, those developing trial protocols should consider the integration of these highly relevant and meaningful COAs as primary or secondary outcome measures,” the researchers wrote.

Other COAs were considered less relevant by participants. For example, a common measure of mobility is the time it takes to climb four steps. Even though mobility problems were considered highly impactful, the caregivers generally thought that the assessment had less relevance for measuring mobility difficulties.

Many caregivers noted that some existing COAs did not reflect disease-specific aspects of Sanfilippo syndrome, such as how the condition tends to worsen over time.

“Participants commonly remarked upon the challenge of accounting for the regression in milestones that is a hallmark of Sanfilippo syndrome, and they desired question sets and response options that permit the capture of declining function,” the scientists wrote.

“New clinical development programs could consider these results to select, modify, and further validate COAs,” they concluded.