You may be able to find something on S7 which is a oneworld carrier to get a bit closer to the destination than OW just to DME.

OK, edited to say - it looks like S7 indeed flies to UUS, although it doesn't show up on the drop-down list if you select LON as the point of origin! Strange website... they seem to want to discourage through-traffic. Anyway, once you select Moscow as the point of origin, UUS is displayed as the destination.