Drug developers have increased the number of postmarketing studies

which they conduct on newly-approved medicines over the past six

years, but sponsors believe this work has contributed little to their

understanding of the new products, according to a new survey carried

out by the Tufts Center for the Study of Drug Development (Tufts CSDD).

Sixtyeight percent of clinical study sponsors and 79% of non-clinical study

sponsors told the Tufts researchers that postmarketing study results have contributed either marginally or not at all to their understanding of the safety, efficacy or quality of their new products, although 32% felt the studies had “significantly or very significantly” increased their understanding.

Considerable progress has been made since the US Food and Drug Administration (FDA) regulation requiring sponsors to provide annual reports on the status of such studies took effect in 2001, but a major challenge faced by drug sponsors is completing the studies on time, according to Tufts CSDD associate director Christopher-Paul Milne. While over half of all postmarketing studies for which final study reports were submitted were finished by their projected completion date, 45% were delayed due to enrollment problems, technical difficulties, additional FDA requirements or sponsors expanding the scope of their own studies, the survey found.

Other findings included that:

- clinical studies took an average of 10 months longer to complete

and cost nearly nine times as much as non-clinical studies;

- postmarketing studies are typically the responsibility of

applicable R&D departments (clinical development, preclinical,

toxicology, laboratory, etc) and not marketing departments, as some

critics of the Prescription Drug User Fee Act (PDUFA) have claimed; and

- during 1998-2005, drug sponsors spent an average of $5.3 million

per clinical postmarketing study, compared to $610,000 for each non-

clinical study.