My impression of transhumanism is that it is technological eugenics. Although I’m not sure how close that comes to an apt description, as I don’t know much about it. Actually just looking around in order to respond to your comments , I learned the ‘movement’ is ‘larger’ than I presumed apparently there is a domestic political party established enough to have fielded a presidential candidate and affiliates with other similar political organizations multinationally.
Ive found what looks like a philosophic critique and perhaps a discussion on the bioethics of transhumanism. :
https://academic.oup.com/jmp/article/42/3/237/3817401