Trial of Lixisenatide in Early Parkinson's Disease

BACKGROUND

Lixisenatide, a glucagon-like peptide-1 receptor agonist used for the treatment of diabetes, has shown neuroprotective properties in a mouse model of Parkinson's disease.

METHODS

In this phase 2, double-blind, randomized, placebo-controlled trial, we assessed the effect of lixisenatide on the progression of motor disability in persons with Parkinson's disease. Participants in whom Parkinson's disease was diagnosed less than 3 years earlier, who were receiving a stable dose of medications to treat symptoms, and who did not have motor complications were randomly assigned in a 1:1 ratio to daily subcutaneous lixisenatide or placebo for 12 months, followed by a 2-month washout period. The primary end point was the change from baseline in scores on the Movement Disorder Society-Unified Parkinson's Disease Rating Scale (MDS-UPDRS) part III (range, 0 to 132, with higher scores indicating greater motor disability), which was assessed in patients in the on-medication state at 12 months. Secondary end points included other MDS-UPDRS subscores at 6, 12, and 14 months and doses of levodopa equivalent.

RESULTS

A total of 156 persons were enrolled, with 78 assigned to each group. MDS-UPDRS part III scores at baseline were approximately 15 in both groups. At 12 months, scores on the MDS-UPDRS part III had changed by -0.04 points (indicating improvement) in the lixisenatide group and 3.04 points (indicating worsening disability) in the placebo group (difference, 3.08; 95% confidence interval, 0.86 to 5.30; P = 0.007). At 14 months, after a 2-month washout period, the mean MDS-UPDRS motor scores in the off-medication state were 17.7 (95% CI, 15.7 to 19.7) with lixisenatide and 20.6 (95% CI, 18.5 to 22.8) with placebo. Other results relative to the secondary end points did not differ substantially between the groups. Nausea occurred in 46% of participants receiving lixisenatide, and vomiting occurred in 13%.

CONCLUSIONS

In participants with early Parkinson's disease, lixisenatide therapy resulted in less progression of motor disability than placebo at 12 months in a phase 2 trial but was associated with gastrointestinal side effects. Longer and larger trials are needed to determine the effects and safety of lixisenatide in persons with Parkinson's disease. (Funded by the French Ministry of Health and others; LIXIPARK ClinicalTrials.gov number, NCT03439943.).

Clinical heterogeneity of neuro-inflammatory PET profiles in early Alzheimer's disease

The relationship between neuroinflammation and cognition remains uncertain in early Alzheimer's disease (AD). We performed a cross-sectional study to assess how neuroinflammation is related to cognition using TSPO PET imaging and a multi-domain neuropsychological assessment. A standard uptake value ratio (SUVR) analysis was performed to measure [18F]-DPA-714 binding using the cerebellar cortex or the whole brain as a (pseudo)reference region. Among 29 patients with early AD, the pattern of neuroinflammation was heterogeneous and exhibited no correlation with cognition at voxel-wise, regional or whole-brain level. The distribution of the SUVR values was independent of sex, APOE phenotype, early and late onset of symptoms and the presence of cerebral amyloid angiopathy. However, we were able to demonstrate a complex dissociation as some patients with similar PET pattern had opposed neuropsychological profiles while other patients with opposite PET profiles had similar neuropsychological presentation. Further studies are needed to explore how this heterogeneity impacts disease progression.

Does urine drug abuse screening help for managing patients? A systematic review

BACKGROUND

In the field of addiction, assessment of psychoactive substance use is a key element. Nevertheless, self-reports and clinical examination underestimate the use of psychoactive substances. The implementation of urine drug screening tests (UDS) should improve this assessment. While the diagnostic value of UDS is well demonstrated, the consequences of carrying out UDS on medical management have not been established. Our aim was to summarize the evidence pertaining to the efficacy of UDS for medical management.

METHODS

A systematic review of clinical trials, quasi-randomized and observational studies was performed using PubMed, Cochrane database of systematic review, Cochrane central register of controlled trials, PsycINFO, National Institute on Drug Abuse, ISI Web of Science. The methodological quality was assessed with the score developed by Starrels et al.; the report quality using the CONSORT and the STROBE checklists. The main outcome was medical management or consequences of management for patients in terms of psychoactive substance consumption and its complications, be they medical, social or professional.

RESULTS

Eight studies met the inclusion criteria: one randomized clinical trial, two quasi-randomized studies, one cohort, and four cross-sectional studies. The methodological quality was judged to be poor, with the exception of the randomized clinical trial (fair quality). The value of UDS in managing patients was not clearly indicated in these studies.

CONCLUSIONS

Few studies, with poor quality, have assessed the value of UDS in managing patients using psychoactive substances; though with insufficiency to demonstrate the interest of carrying out UDS. Therefore, pragmatic intervention studies are necessary.