Would you agree that for every year added to your life, a year should also be added to all those in third world countries?
My main argument is against the wealthy buying time that others cannot. This is why I'm not against say, penicillin and such.
If you feel that is a bad argument, please explain why. If you feel it's fair, then I think we may agree. I'm not against humanity living longer, I'm against some select few doing so.
"I should get to live longer and everyone else can rot" would be a particular sort of evil.
However what I don't agree with is going from there to "unless everyone can have it, noone can". An awful lot of medicine is not (yet) available to everyone in the world, and while I think it should be, and we should work towards every last human being having access to free, socialised healthcare of the highest quality, you won't find me calling for denying cancer treatments to those in wealthy nations because other nations can't foot the bill.
Well, the other side of the coin is whether those folks even want to live longer.
We have gotten so used to being generally blind to essentially slave labor to support our lifestyles. Is it fair if we double our lifespan while those stuck in poverty making our products don't, or perhaps don't even want to?
I don't think very much is fair about anything in that picture, but I also don't think we should hold back advances or treatments while we work that out, nor do I think that it's particularly useful to relate those two phenomena specifically, you could as well say "Is it fair we use jet-skis while those stuck in poverty making our products have such a poor quality of life? Is it fair to use iphones while those stuck in poverty making the iPhones have such a poor quality of life?", and to be honest I'm slightly inclined to say "no" to that last one...
Significant longevity treatment is likely to be highly disruptive to our society in many ways, but I don't think that we should either fall for the fallacy that we can accurately predict those ways, nor succumb to the idea that we won't or can't adapt positively.