Not sure how far east on Olympic but if closer to the coast, consider PCH to Topanga or Malibu Canyon.
If your job is on the east side of the Calabasas grade then either
PCH to Topanga to (Mulholland OR 101) to Calabasas or
PCH to Malibu Canyon to Mulholland to Calabasas or
PCH to Malibu Canyon/Las Virgenes to the 101.
If on the west side (like where Countrywide is at Las Virgenes and the 101) then just PCH to Malibu Canyon/Las Virgenes.
Any of these routes will at least be scenic and they would be reverse commutes. You should at least try these routes out and familiarize yourself with them just in case there is an accident on the 405.
Monitor
www.sigalert.com during your expected commute times. See if the Sepulveda pass is red. If so, then try those other routes....a lot will come from trial and error.