Newer diabetes drugs are often touted as "better" by the manufacturers, especially as they don't have the risk of hypoglycemia and weight-gain side effects that sulfonylureas have. But this advantage comes at a price: higher cost. These drugs are protected by patents for years, and the manufacturers can, and do, charge whatever they can get away with.
A study on this subject was recently published in Diabetes Care that caught my attention: Second-line Agents for Glycemic Control for Type 2 Diabetes: Are Newer Agents Better? The authors of the present study looked the issue of whether the newer drugs improved patient outcomes. They evaluated four common treatment programs for T2DM, in terms of effectiveness, quality of life, as well as their cost. These treatment programs all included metformin as the first-line drug for diabetes, then added either (1) a sulfonylurea (plus insulin if later needed), or (2) a dipeptidyl peptidase-4 inhibitor (plus insulin if later needed), or (3) a glucagon-like peptide-1 receptor agonist (plus insulin if later needed), or (4) insulin added immediately to metformin. (DPP-IV inhibitors include Januvia, Onglyza and Tradjenta; GLP-1 agonists include Byetta, Victoza and Bydureon).
Rather than do a clinical trial, the researchers used a complicated simulation model that involved reviewing records from a large, national US health plan for 37,501 T2 patients age 40 or older, then looking at some fancy measurements they called lifeyears (LYs) and quality-adjusted life-years (QALYs). They also looked at average time to insulin dependence, and expected medication costs.
They found that the LYs and QALYs were similar for the four treatment regimens. Or, if I correctly understand their profuse use of jargon, all the treatment programs worked about the same in terms of diabetes outcomes.
But their conclusion concerning cost was telling:
"Significant differences were observed in the expected medication cost per QALY incurred by the four treatment regimens. Compared with using sulfonylurea as a second-line agent, which was the least expensive treatment regimen, use of DPP-4 inhibitor was associated with a mean per-person additional medication cost of 141 USD per QALY for women and 160 USD per QALY for men. Use of GLP-1 agonist incurred a mean additional medication cost of 191 USD per QALY for women and 216 USD per QALY for men... and use of insulin as a second-line agent incurred a mean additional medication cost of 150 USD per QALY for women and 170 USD per QALY for men..."
So the newer drugs are more expensive, and don't do much better than the older sulfonylurea drugs when used as add-on therapy for T2DM patients who already taking metformin. Are there any offsetting factors to justify the more expensive drugs? Sure. As mentioned earlier, the new drugs are less likely to cause hypoglycemia and weight gain. And adherance to complicated diabetes programs might be lessened if the drug is once a day (or, on the other hand, worsened if the drug requires injection as do the GLP-1 agonists).
And, of course, the newer drugs are better for the bottom line of the drug companies that develop them.