Both どんなに and いくら, when preceding a verb + + ~ても, mean "no matter how much ..." However, using どんなに requires an expression in the negative sense, while いくら does not.
The following sentences come from the Japan Foundation Basic Japanese-English dictionary, Bonjinsha, 1986.
Donna ni isoidemo, kisha niwa ma ni aimasen.
No matter how much you hurry, you will not make it in time for the train.
Note that for nouns, どんな is used in the affirmative sense. It indicates something incompletely known to the speaker.
Ano hito ni kikeba, donna koto demo wakarimasu.
If you ask that person, he knows anything.
On the other hand, we can use いくら for both positive and negative verbs:
Ikura takakutemo kaimasu.
I'll buy it no matter how expensive it is.
There's no reply no matter how often you call.