British pharmaceutical company GlaxoSmithKline announced this week that it was ready to submit its once-weekly drug for controlling blood sugar for approval. The announcement came following the results of a series of clinical trials, called HARMONY, that have shown effectiveness without wowing investors.

As reported by MedPage Today and the Wall Street Journal, the trial results for HARMONY 6, released April 3, showed that albiglutide reduced HbA1c levels by .82 percent compared to a .66 percent reduction for patients taking insulin before meals.

In addition the patients taking albiglutide lost an average of 1.6 pounds compared to the insulin treated patients who gained 1.8 pounds. Side effects were nausea that occurred in 13 percent of those taking albiglutide compared to 2.1 percent of those taking insulin, and vomiting occurring in 7 percent of the albiglutide compared to 1.4 percent of the insulin group.

The company’s press release did not provide details about the trials, such as how many people were enrolled, or how long people were taking the drugs. And the results have not yet been published in medical journals. Nevertheless the results coupled with results of other HARMONY trials were sufficient to convince Glaxo that it could be successful in seeking approval to market the drug.

Albiglutide is similar to Victoza and Bydureon, in that it binds the glucagon-like peptide, or GLP-1, which stimulates the release of insulin when glucose levels become too high. Normally when food is eaten, GLP-1 is released into the blood by the intestine. It’s two main effects, according to Diabetesnet.com, are to slow the absorption of food in the intestine, and to stimulate the pancreas to boost insulin production.

But GLP-1 is like a catalyst, it works just long enough to trigger a reaction before it is broken down by another enzyme. GLP-1 agonists like Albiglutide or Victoza bind to GLP-1 in such a way as to protect it from being broken down, thus extending the length of time it remains effective in stimulating production of insulin.

According to MedPage Today, last November Glaxo released preliminary results from another trial in the HARMONY series, which found that albiglutide effectively reduced HbA1c, but was not as effective as liraglutide (Victoza).

As a result of these findings, The Wall Street Journal says investors are unimpressed with albiglutide, predicting sales might range from $250 million $750 million, which is considered modest by pharmaceutical industry standards.

Novo Nordisk’s Victoza led the introduction of GLP-1 agonists into the market with twice-daily injections. That was followed by Lyxumia from Sanofi and Byetta from Amylin and Lilly, which recently won approval for its once-a-week injection formulation named Bydureon.