I am sorry to hear about your friend.
I sort of did Interferon. I say sort of because I had a very bad reaction to it and could not continue. I only did 6 full high dose treatments and then I had to quit.
LOTS and LOTS of people do Interferon with only the normal side effects which include mainly fatigue, body aches, head aches, etc... There are a lot of studies on Interferon... some that say that it does not do all that they would like - but it is the only treatment there really is so that is why they push it.
There is a lot of info out there - do some searches. I wish, wish, wish I could give you another site to go to that could give you a LOT of Melanoma Patient Information... But they don't allow that on here.
I wish I could be more helpful - but Interferon nearly killed me, so I could not continue the treatments. I wish your friend the best!