I'm sorry to hear about your poor little guy. What an awful thing for you and the fish to have to go through.
I've never had good luck with MelaFix. I know that everyone who is anyone, all the way up to Jack Wattley, recommends MelaFix.
My platies were having fungal/bacterial issues (fin rot, lethargy, poor appetite, clamped fins, thick slime coat...they were pretty bad off) and I used Fungus Cure, which is made by Jungle Labs. I've never been a fan of Jungle Labs products, but I dropped in the tabs at a half dose and it fixed my fish right up! Of course there's no such thing as a miracle cure, but if this disease is resistant to MelaFix, you may want to try something with a little more kick. That's just my two cents worth. Best of luck!
