The class of GLP-1 drugs has been found anecdotally (and repeatedly) to be useful for Type 1. But the companies that developed GLP-1 drugs applied for FDA approval to address the Type 2 market that is 10 times larger than the Type 1 (which makes sense). So the companies that developed GLP-1 drugs got approval for Type 2 first. Once the GLP-1s were approved for Type 2 they could then be prescribed by doctors “off-label” for Type 1 and many doctors found that they actually worked quite. What wasn’t done is safety testing specifically on Type 1 and that remains a open question.
But companies have turned back to the FDA to seek approval for Type 1 in certain circumstances. But the road has not been all smooth. The study results do show that GLP-1s work on Type 1 but not as well as for Type 2. And in fact, Novo Nordisk stopped pursuing Victoza las August 2015. The well known endocrinologist Dr. Irl Hirsh when asked about this withdrawal noted "
“Clinically I can’t predict who has a great response, who has a modest response, and who has no response. Put it together in a trial, and the impact is not large enough for a new indication. What would be important is to try to figure out why we see such heterogeneous response rates for glucose and weight. I am hopeful there is enough data available for post-hoc analysis to see what is associated with an improved response.”
While it is true that there have not been separate safety studies of the GLP-1s in Type 1 patients, we don’t have any real indication that the risks are any different than the risks in Type 2. The GLP-1s are being approved by the FDA for use with insulin and we are seeing a number of insulin/GLP-1s in the pipeline. There may be some higher risks of hypos but there isn’t any indication that this is significant. So we would probably assume that the safety profile for Type 1 is close to the safety profile for Type 2. And the reason that it isn’t approved for Type 1 is simply that the FDA considers Type 1 and Type 2 separate conditions and requires separate applications and studies for approval for treatment of those conditions. Despite that, as we learn more an more about Type 1 and Type 2 we see that often they share the same sorts of defects and both may respond to drugs like GLP-1s.
i think it is reasonable to talk with your doctor about GLP-1s as off label use. Have a specific discussion of safety and adverse effects and stop the drug should you have any adverse problem, even one that isn’t listed. The GLP-1s actually work by lowering the glucagon spike associated with meals (one major diabetes defect) so you may find it really helps as Victoza did before