Merck: Long-acting diabetes pill in testing as effective as once-a-day predecessor Januvia

Drugmaker Merck & Co. says its experimental Type 2 diabetes drug performed about as well as its older daily pill, Januvia, in a late-stage patient test.

The new drug, once-weekly omarigliptin, reduced study participants' three-month average blood sugar level, called hemoglobin A1C, a fraction more than Januvia.

In patients with an initial hemoglobin A1C level of 8 percent or higher, omarigliptin reduced that by 0.79 percent, versus 0.71 percent with Januvia. Patients generally aim for below 7 percent.

Januvia, a top-selling diabetes medicine, had 2014 sales of $4 billion. Its U.S. patent expires in 2022.

Omarigliptin is being tested in about 8,000 patients across 10 late-stage studies, the last step before seeking approval. Merck plans to apply for U.S. approval by year's end and did so last year in Japan.