Analysis of Systemic Antibiotics Approved in the U.S. between 1980 and 2009

OBJECTIVES: Access to effective antibiotics is critical to public health; antibiotic resistance threatens to undermine the health gains derived from these wonder drugs. The objectives of this study were to describe the new molecular entities (NMEs) and new therapeutic biologic applications (BLAs) approved by the FDA in the period 1980-2009 and to assess differences between systemic antibiotics and other therapeutic classes NMEs/BLAs approved by the FDA in the study period. METHODS: The study included all NMEs/BLAs approved by the FDA in the study period. Data derived from the FDA and were updated through December 31, 2009. Differences between proportions were assessed using chi-square test. Significant level was set at 0.05. RESULTS: The FDA approved 739 NMEs (8.3% systemic antibiotics) and 75 BLAs (0.0% systemic antibiotics) during the period of analysis. The FDA granted priority review to 27.9% of the systemic antibiotics and 44.2% of the NMEs of other classes (p<0.01). None of the systemic antibiotics had orphan drug designation for the first FDA approval of the NME/BLA in comparison with 22.6% of other classes (p<0.001). A total 44.3% of systemic antibiotics and 12.2% of other classes were discontinued from the market (p<0.001). Systemic antibiotics represented 12.9%, 6.8% and 3.6% of the total number of approvals in the 1980s, 1990s and 2000s, respectively. The highest number of FDA approvals in the study period were cardiovascular (17.8%, 12.2%, 7.2% of approvals in 1980s, 1990s, and 2000s respectively), nervous system (12.0%, 12.2%, 14.3%) and antineoplastic and immunomodulating agents (6.2%, 15.4%, 20.3%). The largest increase in approvals was HIV antiretrovirals (0.4%, 3.9%, 4.0%). CONCLUSIONS: FDA approvals and subsequent discontinuations varied significantly by therapeutic class in the study period. Classes with large number of potential patients such as cardiovascular drugs and antibiotics decreased as a percentage of total FDA approvals; approvals in other classes -HIV antiretrovirals and antineoplastic and immunomodulating agents - increased. Antibiotics in particular were prone to a significant number of discontinuations. These differences occurred in spite of all drugs (including antibiotics after 1997) having similar patent and exclusivity regulation in place. Trends in FDA approvals may be related to the status of reimbursement, science and technology, commercial and R&D strategies, availability and characteristics of alternative therapies, and higher risk/benefit ratio for HIV antiretrovirals and antineoplastic agents. The implementation of antibiotic conservation programs may be critical given the reduction in antibiotics approvals, their high market discontinuation rate and the development of resistance.