Wrap chain, rope, or webbing around the stalk a couple of times and pull on that instead?
I was also thinking of a fence post puller, but not sure that would work. Description indicates a straight, tough stalk. so...
"Devil's club is very sensitive to human impact and does not reproduce quickly. The plants are slow growing and take many years to reach seed bearing maturity, and predominately exist in dense, moist, old growth conifer forests in the Pacific Northwest.[2]"
That's good news. I had a similar problem with Canada Thistle and mowed it down with my lawn tractor, which kept the area clear for a couple of years.