The Paediatric Exclusivity Program, established by the US Congress in 1997 to encourage drugmakers to conduct more clinical trials of their products in children, has proved highly lucrative for blockbuster drugs but produces more modest returns on investment for many other products, reports a study published in the Journal of the American Medical Association February 7 issue.
The Program, which is due to expire this year, gives drugmakers an extra six months’ patent protection, or marketing exclusivity, to companies for performing studies to obtain more paediatric data on their products. Study authors Jennifer Li of the Duke Clinical Research Institute in North Carolina and colleagues say that while the Program has been successful in generating more than 300 paediatric studies, and over 115 products have undergone labeling changes for paediatric use, critics see it as a windfall to the prescription drug industry because, they claim, profits gained from the patent extensions greatly exceed the cost of conducting the studies.
Government and industry sources put paediatric study costs in a range from $1 million to over $35 million, but research based on a survey of drug companies estimated such costs to average $3.87 million per written request (in which the Food and Drug Administration lists required elements for paediatric exclusivity), the researchers add.
Dr Li et al analyzed data to determine the costs of the paediatric trials and if the incentives provided by the Best Pharmaceuticals for Children Act of 2002 are disproportionate to the costs of the studies. Evaluating studies submitted during 2002-4 and selecting one treatment for: allergy/immunology, cancer, central nervous system, cardiovascular, psychiatry, endocrine, gastrointestinal, infectious disease and other (eg, kidney transplantation), they discovered a wide variety in the distribution of net economic return for six months of exclusivity, from -$8.9 million to $507.9 million. Also, net return-to-cost ratio ranged from -0.68 to 73.63.
This shows that the Program overcompensates blockbuster products for performing clinical trials in children, the researchers conclude, and they say further work is needed to ascertain what constitutes adequate economic return to manufacturers in return for their risk. “Clearly, however, the greatest return of the exclusivity program is the benefits derived in obtaining new information relevant and applicable toward the care of children, and this benefit should not be compromised,” they emphasise. Lynne Taylor