Well the most striking thing about this "idea" is when I was with another Star Trek fan and we listening to tunes in the car. The song that came up was "Cygnus X-1" from Rush, so I started explaining the song, and its sequel "Hemispheres." The two tracks have a very similar premise to this series.
And what "series" are you talking about?
I'm quite familiar with both songs.
In fact, a friend of mine wanted to do an animated film to the former.
Their similarity to the premise seems limited to someone going into a black hole and ending up in the distant past and affecting human history: which means they have a punchline in common, not a story.
It should be pointed out that both songs were released (Sept. 1977 and and October 1978, respectively) after Planet of the Titans
was aborted, lest anyone think there was borrowing going on.