PHP - Removing \n from JSON response

I have a (simplified) JSON response from an API call that looks like below

{"status":true,"action_values":"{\n \"range_from\": \"0\",\n \"range_to\": \"0\"\n}"}

I am trying to remove the \n characters from above using PHP but it doesn't seem to be working.

I try:

$trimmed = str_replace("\n", "", $response);

Where $response is my JSON string as above. But this does not remove/replace the \n character.