PHP Regex match one letter and one number

Question

I'm trying to replace any occurrences when you find a single letter followed by a single number in a string.

$word = 'AB001J1'; //or ZR010F2 or ZQ10B5

echo str_replace('/^(?=.*\pL)(?=.*\p{Nd})/', '', $word);

Trying to get the result AB001 //or ZR010 or ZQ10