Do you know what medicine you're taking . . . really?

If a recent move by the Food and Drug Administration is any indication, it will soon be impossible for you to find out. Last month, an agency advisory committee voted to recommend approval of the drug EP2006 as a stand-in for Neupogen, a popular biologic medication -- a type of advanced drug created from living cells -- that strengthens the immune system of chemotherapy patients.

The FDA will likely allow the sale of EP2006 and similar drugs and may allow the manufacturer to market them using the same name as the innovator biologic medicines they're based on. That's bad news for patients, who won't know which version of a medication they're receiving: the original biologic or a replica that is "similar" but not identical.

The FDA should not go down this path. For the sake of patient safety, it should require that drugs like EP2006 have separate, distinct names.

Scientists develop biologics by using living cells to grow proteins that can treat serious diseases like cancer, diabetes, and rheumatoid arthritis. Because of the inherent variations between individual living cells, biologics cannot be replicated precisely. That's in contrast to more traditional drugs, which can.

There can be significant structural differences between biologics and their copies -- that's why they're call "biosimilars." Indeed, the FDA found that commercially produced samples of EP2006 had a lower protein content than the biologic they mimic. This variation could alter EP2006's effects.

advertisement | advertise on newsday

These differences don't mean biosimilars are dangerous. They can be safe and effective. But the contrast is important enough that the FDA should distinguish between biologics and biosimilars. Because extensive clinical trials aren't required for biosimilars, new adverse effects will likely remain undetected until the drug hits the market. And if such effects do crop up, a clear naming system would make it possible for physicians to clearly identify the cause.

To see the unfortunate consequences of not having a distinct naming system in place, consider Thailand. By the mid-2000s, the Thai government had licensed a biologic and several biosimilars to treat anemia. Pharmacists routinely switched patients back and forth between the standard biologic treatment and its biosimilars. Because these different versions of the drug all had the same name, doctors had no way of knowing which one their patients received.

This lack of transparency proved disastrous. Some anemia patients taking these drugs contracted a more severe illness called "pure red cell aplasia." Without a distinct naming system, health officials were unable to pinpoint which medication caused the condition. Ultimately, Thailand had to overhaul its drug registry to fix the problem.

Biosimilars have not yet debuted in the U.S. market, so there's still time for the FDA to implement a naming system that properly informs patients and keeps them safe.

Transparency is particularly important to vulnerable patient subgroups like women and ethnic minorities. Because of their unique genetic makeups, these patient populations could suffer severe negative reactions caused by variations in biosimilars.

Before the FDA licenses biosimilar medicines for sale in the United States, it ought to implement a drug-naming system that acknowledges the consequential differences between biologics and biosimilars. This system would protect patient health and allow medical experts to rapidly identify the cause of any negative side effects.

Peter J. Pitts was Food and Drug Administration associate commissioner from 2002 to 2004. He is president of the Center for Medicine in the Public Interest, a nonprofit and nonpartisan organization.