Removing Multiple/Possible Characters From End of Variable

I hate asking for help (some searches usually find the answer), but I can't figure this one out....

I need to strip a handful of possible characters off the end of a variable and have been playing with trim, str_replace and preg_replace with no luck. I can get them to work fine with a specific name/characters but not one that covers all possible options.

Our employees desktop and laptops use a standard naming convention that could have multiple characters at the end of their device name which is based on their name. I am trying to strip off all characters to just get the employee name.

Here are some examples of our devices name:

JDOE

JDOE_L

JDOE-L

JDOE-L2 (or any numeric range such as 2-9)

JDOE2 (or any numeric range such as 2-9)

I am trying to get only the JDOE from the device name.

Any help would be great. Thanks!