This is behind a paywall, if you have access copy and post.
When combined, two drugs alter the activity of a protein complex called target of rapamycin complex 1
The summary article is behind a pay wall but the research paper is open access
Here’s another article on this that is not behind a paywall:
Two-drug combo blunts autism-linked pathway in brain
Still only mouse studies and the researchers “do not have plans to pursue autism-linked conditions”. But some interesting research combining two drugs, one that seems to be a variant of Rapamycin that similarly blocks mTOR activity and another which prevents the first one from crossing the blood brain barrier. Seems their focus is more on being able to focus mTOR blocking to specific tissues and less on autism. But still interesting