Remove trailing char when congregating after merging text in multiple columns to one

I'm trying to congregate text in multiple columns into one column in google sheets. I'm using the following formula. It works but unless there is an item in column E I get a comma at the end of any entry that was in B,C, or D.

=ARRAYFORMULA(IF(ROW(G:G)=1,"Events", IF(A:A="","", B:B) & IF(B:B<>"",", "&C:C, C:C) & IF(C:C<>"",", "&D:D, D:D) & IF(D:D<>"",", "&E:E, E:E))) 

How to I check to see if there are no entries after and thus remove the trailing comma.

For exmaple, this works:

event1, event2, event3, event 4 

but if there is not an item in the last column (E) then it looks like this

event1, event2,