Analysis of cognitive ability and adaptive behavior assessment tools used in an observational study of patients with mucopolysaccharidosis II

Clinical investigator perspectives on patient outcomes in children with neuronopathic mucopolysaccharidosis II during intrathecal idursulfase-IT treatment

BACKGROUND

Mucopolysaccharidosis II (MPS II) is a rare lysosomal storage disease characterized by iduronate-2-sulfatase gene (IDS) deficiency and downstream glycosaminoglycan accumulation. Two-thirds of patients present with neuronopathic disease and evaluating cognitive function in these patients is challenging owing to limitations of currently available tests. During the clinical development of intrathecal idursulfase (idursulfase-IT), regulatory authorities requested qualitative data to further understand the neurocognitive changes observed by the investigators through the clinical trials.

RESULTS

This qualitative study consisted of semi-structured interviews with all nine of the principal investigators who participated in the idursulfase-IT phase 2/3 (NCT02055118) and extension (NCT02412787) trials. These investigators enrolled the 56 patients with neuronopathic MPS II who qualified for the extension phase of the trial. The investigators were asked to rate the disease status of their patients. Of the 56 patients, 49 (88%) were rated as having disease that was improved/improving, stabilized or slowing progression compared with the expected outcomes with no treatment. Three patients were rated as worsening, while the remaining four patients were considered to have slowing progression or worsening disease. Similar results were demonstrated for patients aged from 3 to under 6 years at baseline, with 33 of 39 patients (85%) rated as having disease that was improved/improving, stabilized or slowing progression. Of the seven patients rated with slowing progression/worsening or worsening disease, five of them had an IDS variant other than missense, while two had a missense class variant. All the assigned improved/improving ratings were in patients receiving idursulfase-IT from the start of the phase 2/3 trial. Moreover, patients under 3 years of age at baseline were all rated as either improved/improving or stabilized disease. In a blinded review of patient profiles, investigators were requested to assign a disease status rating to 18 patients with large IDS deletions; 67% of these patients were rated as improved/improving or stabilized disease.

CONCLUSIONS

This qualitative analysis provides a snapshot of clinicians' considerations when evaluating treatment in patients with neuronopathic MPS II, compared with the expected decline in cognitive function in the absence of treatment. The results highlight the importance of robust assessment tools in treatment evaluation.

Clinical characteristics and somatic burden of patients with mucopolysaccharidosis II with or without neurological involvement: An analysis from the Hunter Outcome Survey

Approximately two-thirds of patients with mucopolysaccharidosis II (MPS II; Hunter syndrome) have neuronopathic disease, with central nervous system involvement; one-third have non-neuronopathic disease. This analysis of data from the Hunter Outcome Survey (HOS) compared the clinical manifestations and surgical and nonsurgical procedure history in patients with neuronopathic or non-neuronopathic MPS II. Prospective patients were identified in July 2018 in HOS for inclusion in this analysis as those with stable cognitive impairment status as assessed at 10 years of age and at a minimum of one follow-up visit at 11 to <20 years of age. Patients were stratified according to cognitive impairment status at 10 years into neuronopathic and non-neuronopathic groups, and clinical manifestations and surgical and nonsurgical procedure history were compared between the two groups. In total, 193 patients had cognitive impairment status assessments available (at 10 years and 11 to <20 years of age), 151 of whom had stable cognitive impairment status and were included; 100/151 (66.2%) were in the neuronopathic group and 51/151 (33.8%) in the non-neuronopathic group. The proportion of patients demonstrating manifestations by system organ class and the number of surgical and nonsurgical procedures per patient were broadly comparable in the neuronopathic and non-neuronopathic groups both before and after patients' 10th birthdays. The most common manifestations before patients' 10th birthdays, including facial features, joint stiffness and limited function, and hepatomegaly were reported in >80% of patients in both groups. For the neuronopathic and non-neuronopathic groups, the median [10th percentile, 90th percentile] number of different types of surgical and nonsurgical procedures per patient (3 [1, 6] and 3 [1, 7], respectively) and of all procedures per patient (4 [1, 10] and 5 [2, 11], respectively) before patients' 10th birthdays were similar, although the type of procedure may have differed. Thus, in the first two decades of life, patients with non-neuronopathic disease were found to have similar somatic manifestations to those of the neuronopathic group and undergo procedures for complications as often as those with neuronopathic disease.

Neurodevelopmental status and adaptive behavior of pediatric patients with mucopolysaccharidosis II: a longitudinal observational study

BACKGROUND

Mucopolysaccharidosis (MPS) II is a rare, X-linked lysosomal storage disease. Approximately two-thirds of patients have central nervous system involvement with some demonstrating progressive cognitive impairment (neuronopathic disease). The natural history of cognitive and adaptive function in patients with MPS II is not well-defined. This 2-year, prospective, observational study evaluated the neurodevelopmental trajectories of boys with MPS II aged ≥ 2 years and < 18 years.

RESULTS

Overall, 55 patients were enrolled. At baseline, mean (standard deviation [SD]) age was 5.60 (3.32) years; all patients were receiving intravenous idursulfase. Cognitive and adaptive function were assessed using the Differential Ability Scales, Second Edition (DAS-II) General Conceptual Ability (GCA) and the Vineland Adaptive Behavior Scales, Second Edition (VABS-II) Adaptive Behavior Composite (ABC) scores, respectively. Baseline mean (SD) DAS-II GCA and VABS-II ABC scores were 78.4 (19.11) and 83.7 (14.22), respectively, indicating low cognitive function and moderately low adaptive behavior. Over 24 months, modest deteriorations in mean (SD) scores were observed for DAS-II GCA (-3.8 [12.7]) and VABS-II ABC (-2.0 [8.07]). Changes in DAS-II GCA scores varied considerably, and data suggested the existence of four potential patient subgroups: (1) patients with marked early impairment and rapid subsequent decline, (2) patients with marked early impairment then stabilization, (3) patients with mild early impairment then stabilization, and (4) patients without impairment who remained stable. Subgroup analyses revealed numerically greater DAS-II GCA score reductions from baseline in patients aged < 7 years at baseline (vs. those aged ≥ 7 years) and in patients with DAS-II GCA scores ≤ 70 at baseline (vs. those with scores > 70); between-group differences were nonsignificant. No clear subgroups or patterns were identified for individual changes in VABS-II ABC scores. In total, 49 patients (89.1%) reported ≥ 1 adverse event (AE) and nine patients (16.4%) reported serious AEs.

CONCLUSIONS

Some patients with MPS II had rapid declines in cognitive ability, whereas others remained relatively stable after an initial decline. These insights provide a basis for more detailed analyses of different patient subgroups, which may enhance the definition and understanding of factors that influence cognitive and adaptive function in MPS II.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT01822184. Registered retrospectively: April 2, 2013.

A post hoc analysis of Projected Retained Ability Scores (PRAS) for the longitudinal assessment of cognitive functioning in patients with neuronopathic mucopolysaccharidosis II receiving intrathecal idursulfase-IT

BACKGROUND

Norm-based scores used to assess cognitive ability have clinical value when describing functioning of patients with neuronopathic disorders compared with unaffected, same-age peers. However, they have limitations when used to assess change in cognitive ability between two timepoints, especially in children with severe cognitive decline. Calculation of Projected Retained Ability Scores (PRAS) is a novel method developed to characterize absolute change in norm-based ability test scores. In this analysis, PRAS were calculated post hoc for children with mucopolysaccharidosis II (MPS II; Hunter syndrome) and early cognitive impairment in a 52-week phase 2/3 randomized controlled trial (RCT) and its extension study of intrathecal idursulfase (idursulfase-IT). Patients completing the first year of the extension after receiving idursulfase-IT in the RCT and extension (n = 32 of 34 enrolled) or the extension only (n = 15 of 15 enrolled) were categorized according to changes in Differential Ability Scales, Second Edition, General Conceptual Ability (DAS-II GCA) scores and PRAS at 1 and 2 years. Analyses were conducted in the overall population and a subpopulation aged < 6 years at baseline (idursulfase-IT in the RCT and extension [n = 27] and extension only [n = 12]).

RESULTS

PRAS methodology differentiated patients with decreases in DAS-II GCA scores into three separate categories reflecting below-average cognitive growth rates, plateauing cognitive development, and deteriorating cognitive functioning. After 1 year in the RCT, 72.4% of patients who initiated idursulfase-IT had above-average or average cognitive growth rates in DAS-II GCA scores compared with 53.3% of those who did not receive idursulfase-IT; 6.9% versus 20.0% experienced deteriorating cognitive functioning. Similar results were seen in children aged < 6 years: 76% (idursulfase-IT group) versus 50% (no idursulfase-IT) had above-average or average cognitive growth rates in DAS-II GCA scores; 4% versus 17% had deteriorating cognitive functioning. The difference in the distributions of cognitive categories at 1 year in children aged < 6 years was significant (p = 0.048). At 2 years, the proportions of patients in different cognitive categories were more similar between treatment groups.

CONCLUSIONS

PRAS methodology may help to differentiate changes in cognitive development in MPS II, and therefore may represent a valuable addition to existing approaches for interpreting changes in cognitive scores over time.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02055118 (registration date: 4 February 2014) and NCT02412787 (registration date: 9 April 2015).

Cognitive and adaptive behaviors associated with disease severity and genotype in patients with mucopolysaccharidosis II

BACKGROUND

Mucopolysaccharidosis II (MPS II) is a rare, X-linked lysosomal storage disease caused by pathogenic variants of the iduronate-2-sulfatase gene (IDS) and is characterized by a highly variable disease spectrum. MPS II severity is difficult to predict based on IDS variants alone; while some genotypes are associated with specific phenotypes, the disease course of most genotypes remains unknown. This study aims to refine the genotype-phenotype categorization by combining information from the scientific literature with data from two clinical studies in MPS II.

METHODS

Genotype, cognitive, and behavioral data from 88 patients in two clinical studies (NCT01822184, NCT02055118) in MPS II were analyzed post hoc in combination with published information on IDS variants from the biomedical literature through a semi-automated multi-stage review process. The Differential Ability Scales, second edition (DAS-II) and the Vineland Adaptive Behavior Scales™, second edition (VABS-II) were used to measure cognitive function and adaptive behavior.

RESULTS

The most common category of IDS variant was missense (47/88, 53.4% of total variants). The mean (standard deviation [SD]) baseline DAS-II General Conceptual Ability (GCA) and VABS-II Adaptive Behavior Composite (ABC) scores were 74.0 (16.4) and 82.6 (14.7), respectively. All identified IDS complete deletions/large rearrangements (n = 7) and large deletions (n = 1) were associated with a published 'severe' or 'predicted severe' progressive neuronopathic phenotype, characterized by central nervous system involvement. In categories comprising more than one participant, mean baseline DAS-II GCA scores (SD) were lowest among individuals with complete deletions/large rearrangements 64.0 (9.1, n = 4) and highest among those with splice site variants 83.8 (14.2, n = 4). Mean baseline VABS-II ABC scores (SD) were lowest among patients with unclassifiable variants 79.3 (4.9, n = 3) and highest among those with a splice site variant 87.2 (16.1, n = 5), in variant categories with more than one participant.

CONCLUSIONS

Most patients in the studies had an MPS II phenotype categorized as 'severe' or 'predicted severe' according to classifications, as reported in the literature. Patients with IDS complete deletion/large rearrangement variants had lower mean DAS-II GCA scores than those with other variants, as well as low VABS-II ABC, confirming an association with the early progressive 'severe' (neuronopathic) disease. These data provide a starting point to improve the classification of MPS II phenotypes and the characterization of the genotype-phenotype relationship.

Gentlemen seek harmony but not uniformity: The heterogeneity of entrepreneurial team and organizational resilience

The purpose of this research is to investigate the association of the heterogeneity of entrepreneurial team with organizational Resilience. In an uncertain environment, whether new ventures can form entrepreneurial resilience at the organizational level in adverse events becomes the key to sustainable development. Based on the theory of heterogeneous advantage and identity characteristics, this manuscript constructed a research framework of "Structure-Behavior-Result" and described the mechanism and boundary conditions of the heterogeneity of entrepreneurial team affecting organizational resilience in detail. The role of Confucian traditional culture as a moderator has also been analyzed. Data has been obtained from 390 entrepreneurs in China. All hypotheses were tested using moderated mediation model. It has been found that the heterogeneity of entrepreneurial team has positive effect on organizational resilience. It has also been discovered that cross-boundary search behavior acted as a partial mediator between the heterogeneity of entrepreneurial team and organizational resilience. The Confucian traditional culture strengthens the relationship between them. The results are helpful in understanding the internal mechanism of the heterogeneity of entrepreneurial team affecting organizational resilience. Theoretical and practical implications have been highlighted and future research suggestions have been provided.

Intrathecal idursulfase-IT in patients with neuronopathic mucopolysaccharidosis II: Results from a phase 2/3 randomized study

Two-thirds of patients with mucopolysaccharidosis II (MPS II; Hunter syndrome) have cognitive impairment. This phase 2/3, randomized, controlled, open-label, multicenter study (NCT02055118) investigated the effects of intrathecally administered idursulfase-IT on cognitive function in patients with MPS II. Children older than 3 years with MPS II and mild-to-moderate cognitive impairment (assessed by Differential Ability Scales-II [DAS-II], General Conceptual Ability [GCA] score) who had tolerated intravenous idursulfase for at least 4 months were randomly assigned (2:1) to monthly idursulfase-IT 10 mg (n = 34) via an intrathecal drug delivery device (IDDD; or by lumbar puncture) or no idursulfase-IT treatment (n = 15) for 52 weeks. All patients continued to receive weekly intravenous idursulfase 0.5 mg/kg as standard of care. Of 49 randomized patients, 47 completed the study (two patients receiving idursulfase-IT discontinued). The primary endpoint (change from baseline in DAS-II GCA score at week 52 in a linear mixed-effects model for repeated measures analysis) was not met: although there was a smaller decrease in DAS-II GCA scores with idursulfase-IT than with no idursulfase-IT at week 52, this was not significant (least-squares mean treatment difference [95% confidence interval], 3.0 [-7.3, 13.3]; p = 0.5669). Changes from baseline in Vineland Adaptive Behavioral Scales-II Adaptive Behavior Composite scores at week 52 (key secondary endpoint) were similar in the idursulfase-IT (n = 31) and no idursulfase-IT (n = 14) groups. There were trends towards a potential positive effect of idursulfase-IT across DAS-II composite, cluster, and subtest scores, notably in patients younger than 6 years at baseline. In a post hoc analysis, there was a significant (p = 0.0174), clinically meaningful difference in change from baseline in DAS-II GCA scores at week 52 with idursulfase-IT (n = 13) versus no idursulfase-IT (n = 6) among those younger than 6 years with missense iduronate-2-sulfatase gene variants. Overall, idursulfase-IT reduced cerebrospinal glycosaminoglycan levels from baseline by 72.0% at week 52. Idursulfase-IT was generally well tolerated. These data suggest potential benefits of idursulfase-IT in the treatment of cognitive impairment in some patients with neuronopathic MPS II. After many years of extensive review and regulatory discussions, the data were found to be insufficient to meet the evidentiary standard to support regulatory filings.