Conclusions
The current multicentre trial investigated 4 weeks of treatment with a wide range of doses of TTA-121, a novel oxytocin nasal spray with enhanced bioavailability, and revealed an inverted U-shape dose–response relationship with a peak at a dose lower than that expected from previous studies in subjects with ASD. The ASD social core symptoms were significantly improved with the TTA-121 6 U compared with placebo in the PPS. Although the current trial supports the efficacy of TTA-121 on ASD core symptoms and its safety, improvement did not reach statistical significance in the FAS. Thus, the efficacy should be verified in a future large-scale, parallel-group trial.
Abbreviations
ADOS = Autism Diagnostic Observation Schedule; ASD = autism spectrum disorder; FAS = full analysis set; PPS = per protocol set
Acknowledgements
The corresponding author had full access to the data and held the final responsibility regarding the decision to submit for publication. We acknowledge the invaluable contributions of Ms Yumi Kiyama in the recruitment and screening processes. We thank Bronwen Gardner, PhD, from Edanz Group (https://en-author-services.edanz.com/ac) for editing a draft of this manuscript.
Funding
This research was supported by Japan Agency for Medical Research and Development (AMED) under Grant Number JP19lk0201071, JP20lk0201116, and JP16dm0107134.
Competing interest
There are no conflicts of interest. The investigational drugs in this clinical trial, including TTA-121 and placebo, were provided by Teijin Pharma Limited. Neither the funder nor sponsor had any involvement in the data collection, analyses, writing, or interpretation of the study.
Brain. 2022;145(2):490-499. © 2022 Oxford University Press