We (Colette and I) heard extremely many people complain about this quest before we got to it ourselves. So we expected it to be very frustrating.
Turns out neither of us had any trouble with it whatsoever, as Pugilist and Thaumaturge respectively.
General advice I'd give is, take the time to branch into Conjurer just until level 2, you'll be able to carry Cure to your main class. Tremendous help for fights like this.
And really the only thing I'd suggest for them to fix, reading the complaints on the beta board, is change the cooldown on Antidote. 3 minutes is harsh. Lower it to an antidote every 30 secs or so and the boss would still be tough but would feel less arbitrarily hard, since it seems most people struggling with it are dying to the poison more than anything.