Blood Feud

In biotech, one drug can make a company. For Amgen of Thousand Oaks, Calif., the nation’s largest biotech firm, that drug is the anemia treatment erythropoietin (EPO). The best-selling protein racked up $2 billion in revenues for Amgen in 1999 and is paying for the 87,000-square-meter (285,000-square-foot), state-of-the-art laboratory the company is building in the heart of Cambridge, Mass.

But just a few blocks away, at Transkaryotic Therapies (TKT), some clever Cambridge competitors are set to challenge Amgen’s pre-eminence with a version of EPO they believe gets around Amgen’s suite of patents. If successful, TKT’s “end-around” could lead to additional knockoffs of some of the world’s largest-selling biotech pharmaceuticals.

In the early 1980s, Amgen was first to discover and patent the gene that encodes the EPO protein. To manufacture EPO, Amgen adds a copy of the gene to rodent cells growing in culture. TKT’s strategy calls for using human cells instead; latent copies of the EPO gene are turned on in human cells grown in the lab, bypassing Amgen’s patents on the gene and its production method.

Amgen originally hauled TKT into court in 1997. But TKT sidestepped the legal challenge thanks to a loophole that immunizes companies from patent infringement suits while testing a drug. Now that TKT and its partner, the French-based drug firm Aventis, have finished studies in patients and are preparing to seek FDA approval to market its version of EPO, the parties are set to meet Amgen in a Boston courtroom this April.

Robert Frank, an attorney with Boston’s Choate, Hall & Stewart who represents TKT, says the case will be significant not only because of the money at stake, but also because it will test just how well-defended the patents that undergird biotech’s pioneering companies really are. TKT is betting that it’s found a chink in their armor. After EPO, TKT has secrecy-shrouded plans to take on six more of the top drugs in the worldwide $15 billion protein-therapy market.