Working towards a stable liquid glucagon

By, Lisa Foster-McNulty, MSN, RN, CDE

When new drugs hit the market, lots of research has been done to evaluate their safety and effectiveness.  When you hear about drugs that are in development and the results of research that is being done, you are often hearing about phase III clinical trial results.  This is where the drug is given to large groups of people in order to learn about how effective it is, what the side effects are, how it compares to other treatments, and to gather information that will allow the drug to be used safely.  Many drugs don’t make it past phase I or phase II, so you don’t hear as much about the results of those trials. 

Phase I trials are done on very small groups of healthy people for the first time in order to evaluate safety, learn what is a safe dose range, and to identify side effects.  Phase II trials involve slightly larger numbers of subjects and the drug is further tested for effectiveness and safety.

Right now we do not have a commercially available stable liquid form of glucagon.  Thinking of the artificial pancreas, this will be necessary for the dual-hormone insulin pump.  It would also apply for a new prefilled glucagon pen for treating severe hypoglycemia. 

We have information to share about a multi-center phase II trial studying liquid glucagon.   It is a randomized, double-blind, cross-over study investigating what the drug does to the body, and what the body does to the drug.  The researchers wanted to evaluate G-Pump liquid glucagon at three different doses to see how quickly it absorbs and how long it takes to start to work, as compared to the traditional GlucaGen glucagon, which is reconstituted immediately prior to use.  In this study, the glucagon was given subcutaneously via an OmniPod insulin pump.

This research was done on 19 adults with type 1 diabetes.  They were given 0.3, 1.2, and 2.0 micrograms/kg each of G-Pump glucagon and GlucaGen via an OmniPod.  Xeris Pharmaceuticals is developing G-Pump. 

The G-Pump glucagon was just as effective as GlucaGen at raising blood glucose (BG) levels in a dose-dependent manner, with one exception.  There was a greater rise in BG with G-Pump at the 2.0 microgram/kg dose as compared to GlucaGen at the same dose.  They also noted more pain and redness at the infusion site with G-Pump as compared to GlucaGen.  No serious side effects were reported, and no unexpected safety issues were encountered.  The researchers concluded that G-Pump was a stable liquid glucagon formulation which works in a manner very similar to our existing GlucaGen glucagon.  However, it is associated with more pain and infusion site reactions as the dose increases.

While no one relishes the idea of more pain and redness, the commercial availability of a stable liquid form of glucagon would be a very good thing.  As previously mentioned, it would be essential before a dual-hormone artificial pancreas system could be brought to market.  Glucagon is currently given in emergency situations for unconscious hypoglycemia, and usually administered by lay people.  The fact that it has to be reconstituted is often a deterrent, and therefore, someone who could potentially help might not be willing to try.  The patient may have to wait for the ambulance to arrive.  If a stable liquid form of glucagon were available, early treatment of unconscious hypoglycemia would be more likely.  That can save lives, and that’s a worthwhile tradeoff!