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

Eric Hollander, Genoveva Uzunova, Bonnie P. Taylor, Rachel Noone, Emma Racine, Ellen Doernberg, Katherine Freeman, Casara Jean Ferretti

1 Scopus citations


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.

Original languageEnglish (US)
JournalWorld Journal of Biological Psychiatry
Publication statusAccepted/In press - Jan 1 2018


  • Autism spectrum disorder
  • Trichuris suis ova
  • cytokines
  • pharmacotherapy
  • repetitive behaviors

ASJC Scopus subject areas

  • Psychiatry and Mental health
  • Biological Psychiatry

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