Once per day dosing

The ABC-C is a 58-item caregiver-rated behavior scale used to examine treatment effects on challenging behaviors for individuals with FXS in the following domains: (1) irritability; (2) lethargy/social withdrawal; (3) stereotypic behavior; (4) hyperactivity; and (5) inappropriate speech. Caregiver rates the subject's behavior as follows: 0 = not a problem, l = the behavior is a problem but slight in degree, 2 = the problem is moderately serious, 3 = the problem is severe in degree. Sansone et al. (2012) further subdivided social withdrawal to rate social avoidance in FXS. The subscale includes 4 items which were originally part of the Lethargy/Withdrawal subscale. This subscale captures core aspects of the FXS phenotype related to gaze avoidance, social ''escape'' behaviors, and social anxiety. Subscale score ranges from 0 to 12, higher scores reflect a more problematic behavior. Shown here are the ABC social avoidance subscale mean scores from the 10-weeks follow-up visit.

The ABC-C is a 58-item caregiver-rated behavior scale used to examine treatment effects on challenging behaviors for individuals with FXS in the following domains: (1) irritability; (2) lethargy/social withdrawal; (3) stereotypic behavior; (4) hyperactivity; and (5) inappropriate speech. Caregiver rates the subject's behavior as follows: 0 = not a problem, l = the behavior is a problem but slight in degree, 2 = the problem is moderately serious, 3 = the problem is severe in degree. Sansone et al. (2012) further subdivided social withdrawal to rate social avoidance in FXS. The subscale includes 4 items which were originally part of the Lethargy/Withdrawal subscale. This subscale captures core aspects of the FXS phenotype related to gaze avoidance, social ''escape'' behaviors, and social anxiety. Subscale score ranges from 0 to 12, higher scores reflect a more problematic behavior. Shown are the ABC social avoidance subscale mean scores from the 20-weeks end-of-study visit.

A clinician rated scale utilizing history from the parents or caregiver and incorporating it into a clinical rating for severity. The CGI-S was used at the pre-treatment assessment to judge symptom severity. The 7-point scale ranges from: 1 = Normal; 2 = Borderline Ill; 3 = Mildly Ill; 4 = Moderately Ill; 5 = Markedly Ill; 6 = Severely Ill; and 7 = Extremely Ill. Therefore, the higher the score, the greater the severity of the patient's illness. Shown here are the CGI-S mean scores from the baseline visit.

A clinician rated scale utilizing history from the parents or caregiver and incorporating it into a clinical rating to assess for overall therapeutic response. The 7-point scale ranges from: 1 = Very much improved; 2 = Much improved; 3 = Minimally improved; 4 = No change; 5 = Minimally worse; 6 = Much worse; and 7 = Very much worse. Therefore, the lower the score, the greater the overall improvement as rated by the clinician. The CGI-I was used at the 10 week and 20 week visits. Shown here are the CGI-I mean scores from the 10-weeks end-of-study visit.

A clinician rated scale utilizing history from the parents or caregiver and incorporating it into a clinical rating to assess for overall therapeutic response. The 7-point scale ranges from: 1 = Very much improved; 2 = Much improved; 3 = Minimally improved; 4 = No change; 5 = Minimally worse; 6 = Much worse; and 7 = Very much worse. Therefore, the lower the score, the greater the overall improvement as rated by the clinician. The CGI-I was used at the 10 week and 20 week visits. Shown here are the CGI-I mean scores from the 20-weeks end-of-study visit.

The measure was used to assess parental impressions of progress in two key symptoms: spoken language impairment and social impairment. The distance of the mark from one end is used as the outcome variable for analysis. Caregivers mark on a visual line measuring 10 cm with "worst behavior" at 0 cm and "best behavior" at 10 cm. For each behavior the caregiver is instructed to mark their impression of the behavior at baseline visit and again at the 10-weeks and 20-weeks visits. The calculated distance in cm between the marks drawn at the baseline and follow-up visits thereby demonstrates whether each behavior improved, worsened, or stayed the same during the study, and by how much. Shown here is the mean distance in cm from the "worst behavior" side for the Spoken Language Impairment scale, at baseline. The smaller the value, the worse the behavior. The range is minimum 0 cm to maximum 10 cm.

The measure was used to assess parental impressions of progress in two key symptoms: spoken language impairment and social impairment. The distance of the mark from one end is used as the outcome variable for analysis. Caregivers mark on a visual line measuring 10 cm with "worst behavior" at 0 cm and "best behavior" at 10 cm. For each behavior the caregiver is instructed to mark their impression of the behavior at baseline visit and again at the 10-weeks and 20-weeks visits. The calculated distance in cm between the marks drawn at the baseline and follow-up visits thereby demonstrates whether each behavior improved, worsened, or stayed the same during the study, and by how much. Shown here is the mean distance in cm from the "worst behavior" side for the Spoken Language Impairment scale, at 10-weeks. The smaller the value, the worse the behavior. The range is minimum 0 cm to maximum 10 cm.

The measure was used to assess parental impressions of progress in two key symptoms: spoken language impairment and social impairment. The distance of the mark from one end is used as the outcome variable for analysis. Caregivers mark on a visual line measuring 10 cm with "worst behavior" at 0 cm and "best behavior" at 10 cm. For each behavior the caregiver is instructed to mark their impression of the behavior at baseline visit and again at the 10-weeks and 20-weeks visits. The calculated distance in cm between the marks drawn at the baseline and follow-up visits thereby demonstrates whether each behavior improved, worsened, or stayed the same during the study, and by how much. Shown here is the mean distance in cm from the "worst behavior" side for the Spoken Language Impairment scale, at 20-weeks. The smaller the value, the worse the behavior. The range is minimum 0 cm to maximum 10 cm.

The measure was used to assess parental impressions of progress in two key symptoms: spoken language impairment and social impairment. The distance of the mark from one end is used as the outcome variable for analysis. Caregivers mark on a visual line measuring 10 cm with "worst behavior" at 0 cm and "best behavior" at 10 cm. For each behavior the caregiver is instructed to mark their impression of the behavior at baseline visit and again at the 10-weeks and 20-weeks visits. The calculated distance in cm between the marks drawn at the baseline and follow-up visits thereby demonstrates whether each behavior improved, worsened, or stayed the same during the study, and by how much. Shown here is the mean distance in cm from the "worst behavior" side for the Social Impairment scale, at baseline. The smaller the value, the worse the behavior. The range is minimum 0 cm to maximum 10 cm.

The measure was used to assess parental impressions of progress in two key symptoms: spoken language impairment and social impairment. The distance of the mark from one end is used as the outcome variable for analysis. Caregivers mark on a visual line measuring 10 cm with "worst behavior" at 0 cm and "best behavior" at 10 cm. For each behavior the caregiver is instructed to mark their impression of the behavior at baseline visit and again at the 10-weeks and 20-weeks visits. The calculated distance in cm between the marks drawn at the baseline and follow-up visits thereby demonstrates whether each behavior improved, worsened, or stayed the same during the study, and by how much. Shown here is the mean distance in cm from the "worst behavior" side for the Social Impairment scale, at 10-weeks. The smaller the value, the worse the behavior. The range is minimum 0 cm to maximum 10 cm.

The measure was used to assess parental impressions of progress in two key symptoms: spoken language impairment and social impairment. The distance of the mark from one end is used as the outcome variable for analysis. Caregivers mark on a visual line measuring 10 cm with "worst behavior" at 0 cm and "best behavior" at 10 cm. For each behavior the caregiver is instructed to mark their impression of the behavior at baseline visit and again at the 10-weeks and 20-weeks visits. The calculated distance in cm between the marks drawn at the baseline and follow-up visits thereby demonstrates whether each behavior improved, worsened, or stayed the same during the study, and by how much. Shown here is the mean distance in cm from the "worst behavior" side for the Social Impairment scale, at 20-weeks. The smaller the value, the worse the behavior. The range is minimum 0 cm to maximum 10 cm.

Total of all reporting groups

A standardized test designed to measure developmental functioning and IQ for individuals ranging in age from 2 years to adulthood. Minimal verbal directions are used in the administration to allow assessment of cognitive ability independent of language ability. The Brief IQ screener is composed of 4 subtests: figure ground, form completion, sequential order, and repeated patterns subtests. IQ scores are the sum of the scaled scores for the subtests. Scores range from a minimum of 36 to a maximum of 169.

Growth Scores are useful for the interpretation of an individual child's performance. Since the child's overall ability level is placed along a linear scale. Raw scores for each Leiter-R subtest are converted into Growth Scale Scores. The score is a three-digit number that can range from 380 to 560. Higher scores represent higher ability levels.

The Autism Diagnostic Observation Schedule-Second Edition (ADOS-2) The assessment will provide a continuous metric of autism symptom severity for use in characterizing the participant sample and as a potential moderator of treatment response. The ADOS is a gold-standard measure of current symptoms of autism. Total scores will be used to assign a severity score. Scores range from 1 to 10, with higher scores reflecting more severe impairment

Subjects will receive the Parent Implemented Language Intervention (PILI) in combination with placebo.

Placebo: Once per day dosing

The ABC-C is a 58-item caregiver-rated behavior scale used to examine treatment effects on challenging behaviors for individuals with FXS in the following domains: (1) irritability; (2) lethargy/social withdrawal; (3) stereotypic behavior; (4) hyperactivity; and (5) inappropriate speech. Caregiver rates the subject's behavior as follows: 0 = not a problem, l = the behavior is a problem but slight in degree, 2 = the problem is moderately serious, 3 = the problem is severe in degree. Sansone et al. (2012) further subdivided social withdrawal to rate social avoidance in FXS. The subscale includes 4 items which were originally part of the Lethargy/Withdrawal subscale. This subscale captures core aspects of the FXS phenotype related to gaze avoidance, social ''escape'' behaviors, and social anxiety. Subscale score ranges from 0 to 12, higher scores reflect a more problematic behavior.

The ABC-C is a 58-item caregiver-rated behavior scale used to examine treatment effects on challenging behaviors for individuals with FXS in the following domains: (1) irritability; (2) lethargy/social withdrawal; (3) stereotypic behavior; (4) hyperactivity; and (5) inappropriate speech. Caregiver rates the subject's behavior as follows: 0 = not a problem, l = the behavior is a problem but slight in degree, 2 = the problem is moderately serious, 3 = the problem is severe in degree. Sansone et al. (2012) further subdivided social withdrawal to rate social avoidance in FXS. The subscale includes 4 items which were originally part of the Lethargy/Withdrawal subscale. This subscale captures core aspects of the FXS phenotype related to gaze avoidance, social ''escape'' behaviors, and social anxiety. Subscale score ranges from 0 to 12, higher scores reflect a more problematic behavior. Shown here are the ABC social avoidance subscale mean scores from the 10-weeks follow-up visit.

The ABC-C is a 58-item caregiver-rated behavior scale used to examine treatment effects on challenging behaviors for individuals with FXS in the following domains: (1) irritability; (2) lethargy/social withdrawal; (3) stereotypic behavior; (4) hyperactivity; and (5) inappropriate speech. Caregiver rates the subject's behavior as follows: 0 = not a problem, l = the behavior is a problem but slight in degree, 2 = the problem is moderately serious, 3 = the problem is severe in degree. Sansone et al. (2012) further subdivided social withdrawal to rate social avoidance in FXS. The subscale includes 4 items which were originally part of the Lethargy/Withdrawal subscale. This subscale captures core aspects of the FXS phenotype related to gaze avoidance, social ''escape'' behaviors, and social anxiety. Subscale score ranges from 0 to 12, higher scores reflect a more problematic behavior. Shown are the ABC social avoidance subscale mean scores from the 20-weeks end-of-study visit.

A clinician rated scale utilizing history from the parents or caregiver and incorporating it into a clinical rating for severity. The CGI-S was used at the pre-treatment assessment to judge symptom severity. The 7-point scale ranges from: 1 = Normal; 2 = Borderline Ill; 3 = Mildly Ill; 4 = Moderately Ill; 5 = Markedly Ill; 6 = Severely Ill; and 7 = Extremely Ill. Therefore, the higher the score, the greater the severity of the patient's illness. Shown here are the CGI-S mean scores from the baseline visit.

A clinician rated scale utilizing history from the parents or caregiver and incorporating it into a clinical rating to assess for overall therapeutic response. The 7-point scale ranges from: 1 = Very much improved; 2 = Much improved; 3 = Minimally improved; 4 = No change; 5 = Minimally worse; 6 = Much worse; and 7 = Very much worse. Therefore, the lower the score, the greater the overall improvement as rated by the clinician. The CGI-I was used at the 10 week and 20 week visits. Shown here are the CGI-I mean scores from the 10-weeks end-of-study visit.

A clinician rated scale utilizing history from the parents or caregiver and incorporating it into a clinical rating to assess for overall therapeutic response. The 7-point scale ranges from: 1 = Very much improved; 2 = Much improved; 3 = Minimally improved; 4 = No change; 5 = Minimally worse; 6 = Much worse; and 7 = Very much worse. Therefore, the lower the score, the greater the overall improvement as rated by the clinician. The CGI-I was used at the 10 week and 20 week visits. Shown here are the CGI-I mean scores from the 20-weeks end-of-study visit.

The measure was used to assess parental impressions of progress in two key symptoms: spoken language impairment and social impairment. The distance of the mark from one end is used as the outcome variable for analysis. Caregivers mark on a visual line measuring 10 cm with "worst behavior" at 0 cm and "best behavior" at 10 cm. For each behavior the caregiver is instructed to mark their impression of the behavior at baseline visit and again at the 10-weeks and 20-weeks visits. The calculated distance in cm between the marks drawn at the baseline and follow-up visits thereby demonstrates whether each behavior improved, worsened, or stayed the same during the study, and by how much. Shown here is the mean distance in cm from the "worst behavior" side for the Spoken Language Impairment scale, at baseline. The smaller the value, the worse the behavior. The range is minimum 0 cm to maximum 10 cm.

The measure was used to assess parental impressions of progress in two key symptoms: spoken language impairment and social impairment. The distance of the mark from one end is used as the outcome variable for analysis. Caregivers mark on a visual line measuring 10 cm with "worst behavior" at 0 cm and "best behavior" at 10 cm. For each behavior the caregiver is instructed to mark their impression of the behavior at baseline visit and again at the 10-weeks and 20-weeks visits. The calculated distance in cm between the marks drawn at the baseline and follow-up visits thereby demonstrates whether each behavior improved, worsened, or stayed the same during the study, and by how much. Shown here is the mean distance in cm from the "worst behavior" side for the Spoken Language Impairment scale, at 10-weeks. The smaller the value, the worse the behavior. The range is minimum 0 cm to maximum 10 cm.

The measure was used to assess parental impressions of progress in two key symptoms: spoken language impairment and social impairment. The distance of the mark from one end is used as the outcome variable for analysis. Caregivers mark on a visual line measuring 10 cm with "worst behavior" at 0 cm and "best behavior" at 10 cm. For each behavior the caregiver is instructed to mark their impression of the behavior at baseline visit and again at the 10-weeks and 20-weeks visits. The calculated distance in cm between the marks drawn at the baseline and follow-up visits thereby demonstrates whether each behavior improved, worsened, or stayed the same during the study, and by how much. Shown here is the mean distance in cm from the "worst behavior" side for the Spoken Language Impairment scale, at 20-weeks. The smaller the value, the worse the behavior. The range is minimum 0 cm to maximum 10 cm.

The measure was used to assess parental impressions of progress in two key symptoms: spoken language impairment and social impairment. The distance of the mark from one end is used as the outcome variable for analysis. Caregivers mark on a visual line measuring 10 cm with "worst behavior" at 0 cm and "best behavior" at 10 cm. For each behavior the caregiver is instructed to mark their impression of the behavior at baseline visit and again at the 10-weeks and 20-weeks visits. The calculated distance in cm between the marks drawn at the baseline and follow-up visits thereby demonstrates whether each behavior improved, worsened, or stayed the same during the study, and by how much. Shown here is the mean distance in cm from the "worst behavior" side for the Social Impairment scale, at baseline. The smaller the value, the worse the behavior. The range is minimum 0 cm to maximum 10 cm.

The measure was used to assess parental impressions of progress in two key symptoms: spoken language impairment and social impairment. The distance of the mark from one end is used as the outcome variable for analysis. Caregivers mark on a visual line measuring 10 cm with "worst behavior" at 0 cm and "best behavior" at 10 cm. For each behavior the caregiver is instructed to mark their impression of the behavior at baseline visit and again at the 10-weeks and 20-weeks visits. The calculated distance in cm between the marks drawn at the baseline and follow-up visits thereby demonstrates whether each behavior improved, worsened, or stayed the same during the study, and by how much. Shown here is the mean distance in cm from the "worst behavior" side for the Social Impairment scale, at 10-weeks. The smaller the value, the worse the behavior. The range is minimum 0 cm to maximum 10 cm.

The measure was used to assess parental impressions of progress in two key symptoms: spoken language impairment and social impairment. The distance of the mark from one end is used as the outcome variable for analysis. Caregivers mark on a visual line measuring 10 cm with "worst behavior" at 0 cm and "best behavior" at 10 cm. For each behavior the caregiver is instructed to mark their impression of the behavior at baseline visit and again at the 10-weeks and 20-weeks visits. The calculated distance in cm between the marks drawn at the baseline and follow-up visits thereby demonstrates whether each behavior improved, worsened, or stayed the same during the study, and by how much. Shown here is the mean distance in cm from the "worst behavior" side for the Social Impairment scale, at 20-weeks. The smaller the value, the worse the behavior. The range is minimum 0 cm to maximum 10 cm.

The primary outcome reflects the diversity of vocabulary used. Higher scores reflect more skill. The lowest possible value is zero. No theoretical maximum can be defined because the wordless picture books can lead to a large and indeterminate set of options for the amount of talk and the vocabulary used. In a previous study of a nonpharmacological intervention, the range at baseline was 9-177, and at post-treatment, the range for the combined treated and nontreated groups was 23-214, although these values were not corrected for the number of C-units produced (McDuffie at el. 2018 Developmental Neurorehabilitation).

Subjects will receive the Parent Implemented Language Intervention (PILI) in combination with placebo.

Placebo: Once per day dosing