Parent Prioritization of Meaningful Treatment Targets for Sanfilippo Syndrome

February 18, 2020

Cara O'Neill and Elise Drake, poster presentation at WORLD Symposium 2020At the WORLD Symposium 2020, Cure Sanfilippo Foundation Chief Science Officer Cara O’Neill, MD, FAAP, and Research Projects Coordinator Elise Drake, PhD, gave a poster presentation entitled “Parent Prioritization of Meaningful Treatment Targets for Sanfilippo Syndrome,” on a subset of the findings from the Foundation’s larger Caregiver Preference Study.

The poster presentation reported survey results on caregiver priorities for meaningful treatment benefits for Sanfilippo Syndrome. It drew heavy interest from the patient advocates, scientists, NIH and FDA staff, and industry partners in attendance.

Parent Prioritization 2.7-Handout-PDF image


(as a printable .PDF file)


The study used the following methods:

  • A Best-Worst Scaling (BWS) case 1 experiment was conducted via an online survey of caregivers of children with Sanfilippo syndrome.
  • BWS methodology elicits preference weights for different attributes—in this study, features that represent the impact of Sanfilippo syndrome. Features were selected based on previous qualitative research which identified highly-valued treatment targets of Sanfilippo caregivers.
  • Participants completed 12 choice sets to select features that they considered most- and least-important to address in the context of a non-curative therapy. Figure 1 depicts an example of a BWS choice set item.
  • Subgroup analysis was conducted based on child’s age and caregiver ratings of their child’s disease-specific symptoms. Log-odds importance weights were estimated using random-parameters logit for age group (6 or younger vs 7 or older) and stage (early/mid vs later) based on symptom progression. Due to small sample sizes for Sanfilippo syndrome subtypes C and D, only simple scores (i.e., best-worst scores) were calculated for sub-type analysis. Cluster analysis allowed for estimates of a child’s disease stage based on a combination of caregiver-reported cognitive ability, self-feeding ability, and autistic behaviors. 


The poster reported the following results based on insights from 164 caregivers of children and adults with Sanfilippo syndrome from 14 different countries who completed the Best-Worst Scaling item sets.

BWS Results by Child’s Age:

  • Across both age groups, features with highest importance weights were having pain and unsafe behaviors.
  • Hyperactivity and communicating “no” were significantly more important for caregivers of younger children. Trouble getting around, sleep, and unsafe behaviors were significantly more important for caregivers of children aged 7 and older.

BWS Results by Disease Stage:

  • Pain and unsafe behaviors remained the most prioritized features across stage of disease.
  • Caregivers of early/mid-stage children were significantly more likely to prioritize aggressive/impulsive behaviors, paying attention, feeling frustrated, and following directions than caregivers of later stage children.
  • Caregivers of later-stage children prioritized trouble getting around, worry/anxiety, sleep, and sharing feelings, significantly more than caregivers of early/mid-stage children.

BWS Results by Disease Sub-Type:

  • Simple scores reveal caregivers of children with Type A and B similarly prioritized having pain, unsafe behaviors, and feeling unwell.
  • For Type C, caregivers prioritized aggressive/impulsive toward others, not enough sleep, and having pain.


Caregivers’ relative treatment priorities reinforce the multi-symptom impacts of Sanfilippo syndrome.

The top set of prioritized features span several domains:

  • Health: pain, sleep, and feeling unwell
  • Behavioral: hyperactivity, unsafe and aggressive/impulsive behaviors
  • Motor: trouble getting around
  • Communication: communicating “no” and sharing feelings back-and-forth

Pain and safety, two areas important to child and family quality of life, were most prioritized. Though there were differences by age and severity that reflect the child’s changing needs and function as the condition progresses, overall caregivers’ priorities for disease stage features were fairly consistent.

Additional research targeting the rarer subtypes C and D may elucidate whether there are distinct treatment priorities of those caregivers.

This study provides insight into caregivers’ treatment priorities that will help inform development of therapeutics. Results here indicate that targeted, non-curative therapies that extend beyond global cognitive ability are highly valued by caregiver participants.


(as a printable .PDF file)

Cara O'Neill with Tiina K. Urv, PhD, Program Director for the NIH's Office of Rare Diseases Research

Cara O’Neill of Cure Sanfilippo Foundation with Tiina K. Urv, PhD, Program Director for the NIH’s Office of Rare Diseases Research.

 Cara O'Neill poster presentation at WORLD Symposium 2020


The Foundation is grateful to the parents of children with Sanfilippo syndrome for participating in this study. Additional thanks to the Foundation’s Advisory Committee for its valuable input and to BioMarin, Lysogene, Sobi, and Orchard Therapeutics for their kind funding support.

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If you have questions about the Parent Prioritization of Meaningful Treatment Targets presentation, contact Dr. O’Neill at

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