We prove that the class of reflexive asymptotic-
$c_{0}$
Banach spaces is coarsely rigid, meaning that if a Banach space
$X$
coarsely embeds into a reflexive asymptotic-
$c_{0}$
space
$Y$
, then
$X$
is also reflexive and asymptotic-
$c_{0}$
. In order to achieve this result, we provide a purely metric characterization of this class of Banach spaces. This metric characterization takes the form of a concentration inequality for Lipschitz maps on the Hamming graphs, which is rigid under coarse embeddings. Using an example of a quasi-reflexive asymptotic-
$c_{0}$
space, we show that this concentration inequality is not equivalent to the non-equi-coarse embeddability of the Hamming graphs.