Death's End

Robert Heinlein's Methuselah's Children: the Howard Families.
James Blish's Cities In Flight: antiagathics.
John Wyndham's Trouble With Lichen: Antigerone.
Poul Anderson's "What Shall It Profit?": shielding from cosmic radiation.
Anderson's World Without Stars: the antithanatic.
Anderson's The Boat Of A Million Years: mutations, then athanatics.
Larry Niven's Known Space: boosterspice.

Now:

chemotherapy;
nanorobots;
antibiotics;
vaccinations;
medicines;
electric shocks;
organ transplants;
artificial organs;
genetic engineering;
regenerative medicine;
increasing life expectancy.

Our timeline is following several fictional timelines.