The cost of the newly approved treatment will be about $56,000 a year, much of it paid for by Medicare.
Oncology experts say advances in cancer drugs have played a major role.
Some manufacturers are willing to tie drug price to performance.
It's the seventh such deal for the insurance giant, which is putting pressure on drug makers in an effort to keep costs down.
FTC files case against drug maker for deals cut with two generic firms that extend its monopoly