OPINION: THE VALUE OF GENERIC DRUGS
Author: Christopher Labos
MONTREAL -This week, Novartis was denied a new patent in India for the modified version of its chemotherapy agent imatinib (marketed as Gleevec, or Glivec). Many are calling this a landmark case. But buried by the headlines was a largely overlooked story that might have a much more profound impact on how much society pays for medications in the future.
The story concerns the Federal Trade Commission in the U.S., which has appealed to the U.S. Supreme Court to rule on what has been termed "pay for delay." The practice involves brand-name drug companies paying generic manufacturers to keep their low-cost alternative medications off the market.
A patent on a new medication typically lasts for 20 years in both Canada and the U.S.; however, having a patent does not necessarily imply that the company always has exclusive rights to the manufacture of the product. Frequently, generic manufacturers will challenge patent claims, and often do succeed in gaining approval to produce their cheaper generic equivalents. Sometimes, though, the cost of the potential litigation will motivate both companies to come to a settlement where the generic manufacturer is paid to keep its product off the market for a set number of years; hence the term pay-for-delay.
The practice is apparently quite common and is allowed according to a loophole in the 1984 Drug Price Competition and Patent Term Restoration Act. The FTC has challenged this practice on the grounds that it violates anti-competition laws. It is suing the company Actavis for the payment it received from Solvay Pharmaceuticals, the makers of a testosterone gel for men called Androgel, in exchange for agreeing not to sell its generic version of the testosterone gel. The case has now made it to the Supreme Court, and it is unclear how the court will rule.
The ruling has the potential to dramatically affect the availability of generic medications, as well as future health-care costs. However, despite the lower cost of generic options, public perception is an impediment to more widespread use of generic medications. One survey showed that even though 56 per cent of Americans thought that generics should be more widely used, only 38 per cent said that they would prefer to take generics themselves. The discrepancy reflects a belief that generics are somehow less effective, although there is little evidence to support this view.
In order to be approved by Health Canada, a generic medication must contain the same medical ingredients as the brand-name medication (although it can differ in the non-medical ingredients). Its efficacy is tested using a bioequivalence study. This involves giving the generic and brand-name medications to a small number of healthy volunteers and measuring drug concentrations in the blood. The generic must attain drug concentrations that are 80 to 125 per cent of the brand-name medication, meaning no more than 20 per cent lower or 25 per cent higher. Most medications are approved in this manner; however, this method only assesses the biochemical properties of the medication, not its clinical efficacy. In fact, there are very few studies that have compared generics to brand-name medications in a clinical setting.
As it happens, one Canadian study that has just been released online by the Canadian Journal of Cardiology provides new evidence on this issue.
A group from Western University in London, Ontario (formerly known as the University of Western Ontario), looked at generic and brand-name atorvastatin, which was marketed in Canada and the U.S. as Lipitor. The study looked at patients who were switched from brand-name Lipitor to generic atorvastatin when it became available, and compared them to those who remained on Lipitor. The study found that there were no significant differences in their cholesterol levels after one month of follow-up. Although it would have been ideal if the study had followed patients for a longer period of time, and looked at more significant clinical end points, like the incidence of heart attacks, it is still an important study in that it provides one of the few head-to-head comparisons between a brand-name drug and its generic equivalent.
It may take some time for the public to accept generic medications. Generics do represent a major cost savings for the health-care system and with the aging population, this will likely be a significant consideration in the coming years. Some people will still prefer to stay with brand-name meds, but now I can say with more confidence than ever that generic and brand-name drugs are equivalent.
Whether the U.S. Supreme Court will also see the value of generics remains to be seen. Sadly, they probably don't read the Canadian Journal of Cardiology.