Closely related to the patenting of biochemical pathways is the patenting of genes. I'm not completely thrilled with that, either, but it still makes a bit more sense to me. With these patents, you own the gene and uses for it, but you don't get to claim everything else downstream of it (like the protein it codes for!) In the first genomic gold rush, the USPTO was swamped with gene applications, and granted quite a few of them without too much in the way of defined utility. Since then, they've tightened up, and you're really supposed to spell out what a gene is good for in order to patent it. Generally, that means using the gene as the basis for a diagnostic test.
In that vein, Myriad Genetics holds lucrative patents on the BRCA1 and BRCA2 breast-cancer susceptibility genes (background here), on which it makes plenty of diagnostic revenue. But it's been losing protection in Europe. Earlier this year, they lost their European patent for BRCA2, and now their BRCA1 patent is history, too.
In general, it's harder to get and hold on to such patents with the European Patent Office, but these decisions seem to have been taken on good old prior-art grounds rather than any finer points. It turns out that a British cancer charity research foundation had applied for BRCA2 before Myriad, which would seem to indicate that the latter's patent never should have even been granted. As for BRCA1, New Scientist reports that the Myriad amended their claims for it in 1995, correcting a few base pairs months after their first filing, during which time the sequence was published in the open literature. Whoops! Can't get a patent after that happens.
Myriad seems to have pretty much given up on the European market for these patents some time ago, what with all the legal trouble. But you have to assume that they're going to continue to pump the US market for all it's worth. Meanwhile, Canada (well, Ontario at least) is just ignoring these patents, according to the New York Times.
A question now is whether Myriad's claims are going to hold up over here. If this were a high-level question about the patentability of genes, the arguing could go on for a long time. But if we're just talking prior art, then it just comes down to some relatively simple issues: are their filing dates just as hosed up here, or not? And even if they are, is there anyone motivated enough to challenge them?