Lots of press recently about Merck's brand spankin' new Type 2 diabetes drug, Januvia. Patients seem to like it. The EU likes it. So Wall Street likes it, too. What is so wonderful about this new oral with the Shakespearean name?
Here's what I found out, explained from my extremely laymen's point-of-view:
In addition to insulin, our bodies release certain "incretin hormones" called GLP-1 and GIP. In a healthy body, the ideal amount is released from your gut in response to the amount and type of food you ingest. The role of these hormones is to "increase insulin response to a meal" by suppressing glucagon release (which is good, since glucagon's job is to raise your blood glucose). In people with Type 2 diabetes, GLP-1 and GIP levels are below normal, and -- big AND -- they are intercepted by an enzyme called DPP-4.
This is where Januvia (sitagliptin) comes in. It works to inhibit the DPP-4 that breaks down the GLP-1 and GIP. Got that?
So far, the only other drug on the market that aids (or rather mimics) the action of GLP-1 is Byetta, aka exenatide, which over 500,000 people are now taking, according to authorities. (Not counting Januvia's up-and-coming rival from Novartis, called Galvus -- currently still under FDA review).
In a nutshell, these drugs are part of an emerging class of "incretin-based" therapies that block the DPP-4's destructive function, allowing the incretins to live a long and happy life —- and hopefully fulfill their mission of recharging the beta cells. What this means for patients is better regulation of BG levels, since the incretins trigger beta cell insulin secretion and impede glucose production by the liver.
Still, I had to ask, why is so much better than all the therapies we've already got? It appears Januvia trumps all the others in terms of "tolerability," meaning you feel better on it, don't gain weight, don't tend to go low (hypoglycemia), and don't experience indigestion, heart problems, or swelling. Oh joy! And this translates into less troubles for Merck, of course, with fewer patients calling to complain :)
To lay it on the table, here's a rundown of the drawbacks of most Type 2 diabetes drug choices. Read 'em and weep:
• sulfonylureas (Glipizide, Glyburide) - can cause hypoglycemia, weight gain, and gastrointestinal (GI) distress
• metformin - can cause mild nausea, diarrhea, and gas (aka GI distress)
• TZDs (thiazolidinediones, ie. Actos, Avandia) - can cause weight gain, swelling, and congestive heart failure
• insulin - can cause weight gain and hypoglycemia
So now you want Januvia, right? ah! There is one drawback: The pricetag! Currently over $4 per pill without insurance, and reimbursement is still up in the air. Well... just think of all the money you'll save on Weight Watchers and Rolaids.