Follow-on drugs, not hangers-on, says study
The study was partly funded by Pfizer, whose Lipitor (atorvastatin) entered the statin class of cholesterol-lowerers after Merck's Mevacor (lovastatin) and has become the best-selling drug in the world with global sales of $12.9 billon last year.
“Secure but small steps are the way forward, for the most part,” asserted principal investigator Joshua Cohen, PhD, of the Tufts Center for the Study of Drug Development, who argues that follow-on drugs enhance patient safety and quality of life by adding incremental value.
He based this conclusion on the 2005 edition of the World Health Organization's Essential Drug List, a biannual registry of therapies it deems as vital for developing nations. Follow-on drugs comprise 63% of drugs on the list, first-in-class 37%. Since the group places great value on them, it follows that policies that impede follow-on R&D would have a detrimental impact on public health, Cohen said.
Critics' long standing beef with follow-on drugs and indications, of course, is that many offer little or no benefit to patients.
Merrill Goozner, director of the Integrity in Science project at the Center for Science in the Public Interest, said in an e-mail that he aims his critique of follow-on drugs at “those that clearly have little medical relevance in terms of adding to the armamentarium for fighting disease. [AstraZeneca's] Nexium for Prilosec. [Johnson & Johnson's] Aranesp for Procrit.”
The Tufts researchers chose to look at follow-on drugs for which a new active ingredient is created. Advocates respond that these kinds of follow-ons, even if third or fourth in a class, offer significant advantages when they affect patients differently than the innovator drug. They're important for another reason: as a back-up in instances where the first-in-class drug is withdrawn from the market or has safety concerns.
The study comes amid several new threats to this lucrative niche of drug development. Some argue for scrapping me-toos from the formulary in order to make the national payor system more affordable. “The payor issue is driving a lot of what's being said about drug development,” Cohen said.
The safety issue could pose additional peril. Congress is nearing passage of the legislation for renewing industry fees that largely fund FDA's review process. House and the Senate versions would give the agency power to require drug firms to do post-marketing studies of drug safety. If the bill retains the safety measure, it could require firms to define targets for me-too drugs more specifically, potentially limiting their markets, said Goozner.
The political climate around reimbursement, though, with some arguing for lower payments for me-toos, may represent a larger risk. “Policy should not be geared strictly to breakthrough development,” Cohen said. “If it does that, you're going to exclude what is really the mainstay of innovation.”