The diabetes pill is grabbing market share likes there’s no tomorrow. After 18 weeks, Januvia now commands 7.7 percent of new prescriptions and 4.4 percent of all prescriptions written, according to a research note this morning from Michael King at Rodman & Renshaw, who cites IMS Health data.

Meanwhile, the latest delay for Novartis’ rival Galvus pill, which won’t be available for months now, prompts Prudential Equity’s Tim Anderson to write in his own research note today that Januvia should sop up 50 percent of sales that would otherwise have gone to Novartis. And he’s raising his Januvia sales estimate for this year from $594 million to $723 million. And next year, he sees $1.47 billion in sales.

And Merrill Lynch analyst David Risinger, who also published a note this morning, says Galvus may not be available until early 2009. He notes the FDA may permit additional uses for Januvia, such as part of a cocktail with metformin, in October.[tags]Diabetes, Galvus, Januvia, Merck, Novartis[/tags]