Full Throttle was the creation of Tim Schafer and he came up with it whilst under the employ of LucasArts so intellectual property legally belongs to LucasArts, no matter what The Scafer does.
In that case, the only real way of it being made is either if LA decides to make it, or if someone fronts the money to buy the rights (which would be hard if LA don't want to sell, but considering they haven't made any more money from the FT franchise like they have with Monkey Island, they may sell, should some company be willing to buy).
Frankly, the difference between Full Throttle and Sam n Max is that Full throttle was a great game, Sam n Max was a great game, TV show, and comic. There's a whole lot one can do with such a franchise like Sam n Max whereas with Full Throttle no other company apart from LA would want to do a sequel simply because it's a huge risk.
And I highly doubt LucasArts will bring it back.