How do I remove all classes that start with a certain name?

How do I remove all classes that start with a certain name?

Hello,

Im have tr element that have classes assigned to them. There can be any number of classes.

How would I remove all classes starting with "itemnx"

I have this but I dont believe it'a working.

$("tr.itemno").each(function (x) {              
 $(this).removeClass('*[className^="itemnx"]'); 
});                                             

<tr class="itemno itemnx1 itemnx2 itemnx3"></tr>