This Washington Post story says IVIG use has risen 66% because doctors are using it for off-label purposes, some of which do no good for the patients. CIDP is one of only 6 disorders for which IVIG is FDA licensed. But its’s given to cancer patients and even people with dementia. Hope you can get the story through this link. If not, go to the Washington Post website.
https://www.washingtonpost.com/health/as-off-label-use-spreads-for-lifesaving-niche-drugs-supplies-grow-scarce-leaving-patients-in-the-lurch/2019/09/20/b4cb474a-d8a7-11e9-a688-303693fb4b0b_story.html