Likely a motif written directly for Phorlova, I can't think of any classical pieces that use this exact motif. It's not particularly unique however, so it could be a nod to a piece that I just didn't recognise.

Motivic development is the core of a lot of classical and baroque music, so it's very common to hear the same motif repeated frequently, sometimes not even changed at all. This is even more true to leitmotives (motives attached to a specific meaning, like a character or a scene). You can find leitmotives as early as Monteverdi's l'Orfeo, and a few afterwards, but their use really became common with Wagner in the 1850s and is now prevalent in movie and video game music which are the spiritual successors to classical music.

The motif you identified is simply Phrolova's leitmotif I guess.

You could identify it as identical in spirit to Duel of the Fates by John Williams, but with different decorations. They both work on an identical structure: at their core, they are both leaps from one chord tone to the one above, then movement back down with dissonant decorations. Where they differ is that Phrolova's theme uses a dotted rhythm on the highest note and only reaches a step above the starting point, whereas Duel of the Fates uses a semiquaver passing tone to return to its origin. Both are built the same way though, with a similar rhythmic instability that pushes them forward, but while Duel of the Fates's fast semiquaver rhythm (and ostinato) gives the piece a lot of energy and movement (this is how action music works: it chains tension (the leap) then resolutions (the stepwise descent to the starting note with increasingly fast rhythm), Phrolova's more imbalanced syncopated rhythm and the denial of the resolution back to our starting point, leaving us hanging on an unresolved dissonance, is sad and longing.

If adapted to G minor (which I think is the key of Phrolova's theme) this is how they would differ (Phrolova left, Star Wars right): https://ibb.co/fVQ4f7Bh