The Life Cycle of a Drug: Pediatric Exclusivity

Cutting Edge Information has produced a report containing this graph reporting the return on investment of what the pharmaceutical industry calls life cycle management strategies. As you can see, pediatric exclusivity is a top performer. Pediatric exclusivity is a specific type of marketing exclusivity which adds six months to the time that a brand name drug may be sold to adults. This privilege is attained by conducting relatively inexpensive clinical trials with children. Not all drugs qualify for pediatric exclusivity, e.g., a drug for Alzheimer's is very unlikely to qualify. The FDA maintains a list of drugs for which it is willing to grant pediatric exclusivity and will take requests from industry for drugs that aren't on the list. In practice, this marketing exclusivity in adults has only been claimed for bestsellers.

Someone I know, call her Jane Doe, has taken Plavix since having coronary stents installed. Plavix is the second best-selling medication in the world, so the six month extension of marketing exclusivity from November 2011 to May 2012 will result in  2.5-3 billion USD in sales for partners Bristol-Myers Squibb and Sanofi-Aventis. 

The pediatric clinical trials tested for a "reduction of the incidence of thrombosis in children born with systemic to pulmonary artery shunts for palliation of cyanotic congenital heart disease." See item 38 in this list from the FDA (pdf). The clinical trial was inconclusive and FDA Medical Officer Mark Rose, MD, JD, twice recommended against granting pediatric exclusivity (pdf, pdf) because two of the formulations used were not tested for bioavailability. Why the grant was made is explained by this FDA FAQ.

Q14. If a sponsor submits a pediatric study that meets the terms of a Written Request but the study is not adequate for inclusion in the labeling, will the sponsor get pediatric exclusivity?
A14. Yes. Pediatric exclusivity is not dependent on whether information from the requested study is included in the labeling.

In his reports, Dr. Rose acknowledges that "The studies performed by the sponsor in its pediatric development meet the literal requirements of the PWR [pediatric written request]. However, the sponsor ignored one of the advice terms in the PWR: 'Bioavailability of any formulation used in the studies should be characterized, and as needed, a relative bioavailability study comparing the approved drug to the age appropriate formulation may be conducted in adults.'”

Setting aside the technical issues, however, it is unclear why sick adults must exclusively bear the financial burden of testing in sick children. "Drug companies routinely conduct such tests, even when success is not expected, to receive the six-month patent extension" (Ed Silverman, Pharmalot).