Randomized crossover feasibility trial of helminthic Trichuris suis ova versus placebo for repetitive behaviors in adult autism spectrum disorder

World J Biol Psychiatry. 2020 Apr;21(4):291-299. doi: 10.1080/15622975.2018.1523561. Epub 2018 Nov 16.


Objectives: Inflammatory mechanisms are implicated in the aetiology of autism spectrum disorder (ASD), and use of the immunomodulator Trichuris suis Ova (TSO) is a novel treatment approach. This pilot study determined the effect sizes for TSO versus placebo on repetitive behaviours, irritability and global functioning in adults with ASD.Methods: A 28-week double-blind, randomised two-period crossover study of TSO versus placebo in ten ASD adults, aged 17-35, was completed, with a 4-week washout between each 12-week period at Montefiore Medical Center, Albert Einstein College of Medicine. Subjects with ASD, history of seasonal, medication or food allergies, Y-BOCS ≥6 and IQ ≥70 received 2,500 TSO ova or matching placebo every 2 weeks of each 12-week period.Results: Large effect sizes for improvement in repetitive behaviours (d = 1.0), restricted interests (d = 0.82), rigidity (d = 0.79) and irritability (d = 0.78) were observed after 12 weeks of treatment. No changes were observed in the social-communication domain. Differences between treatment groups did not reach statistical significance. TSO had only minimal, non-serious side effects.Conclusions: This proof-of-concept study demonstrates the feasibility of TSO for the treatment of ASD, including a favourable safety profile, and moderate to large effect sizes for reducing repetitive behaviours and irritability.Clinicaltrials.gov: NCT01040221.

Keywords: Autism spectrum disorder; Trichuris suis ova; cytokines; pharmacotherapy; repetitive behaviors.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Animals
  • Autism Spectrum Disorder* / complications
  • Autism Spectrum Disorder* / parasitology
  • Autism Spectrum Disorder* / therapy
  • Behavior* / physiology
  • Cross-Over Studies
  • Double-Blind Method
  • Feasibility Studies
  • Humans
  • Hypersensitivity / complications
  • Hypersensitivity / therapy
  • Irritable Mood* / physiology
  • Ovum
  • Pilot Projects
  • Therapy with Helminths* / standards
  • Trichuriasis
  • Trichuris* / physiology
  • Young Adult

Associated data

  • ClinicalTrials.gov/NCT01040221