The 2003 Vuelta used this climb including the extension to Cam Basque. It was a similar stage but slightly easier, using Pourtalet and Aubisque in place of Aspin and Tourmalet (Pourtalet south is easier than Aspin east, but Aubisque and Tourmalet are a decent comparable, both being just over 17km at just over 7%, Tourmalet slightly tougher but it's negligible)
It was in a similar position in the race (stage 7, first major mountain stage, day after a significant GC stage). It was the day after a 44km ITT rather than a medium mountain type stage, and by and large the breakaway settled things while ONCE managed things for race leader Isidro Nozal, but he still lost a bit of time as things broke up.
You can see the stage here: