An Analysis of Antibacterial Drug Development Trends in the United States, 1980-2019.

We present a longitudinal analysis of investigational new drug applications (INDs) for new, systemic antibacterial drugs under active development between 1980 and 2019, evaluating the characteristics of these investigational drugs and the outcomes of these drug development programs. The number of INDs in active development declined by two-thirds, from 39 active INDs at its peak in 1987 to a low 13 in 2001, with decreased development of new cephalosporin, quinolone, and macrolide drugs and reduced participation from large pharmaceutical firms. Antibacterial drug development activity rebounded substantially from 2002 to 2009, primarily led by involvement of small pharmaceutical companies. As of 31 December 2019, the number of active INDs has declined to an 11-year low, and the number of antibacterial INDs initiated with the US Food and Drug Administration during 2010-2019 was lower than any of the previous 3 decades. Antibacterial drug development programs initiated in the 1980s and 1990s had high success rates, with >40% of INDs obtaining marketing approval, in a median time of about 6 years from IND receipt to approval. For drug development programs initiated between 2000 and 2009, we found that IND-to-approval rates reduced to 23%, with median development times for approved antibacterial drugs increasing to 8.2 years. The majority of INDs in development as of 31 December 2019 come from already established drug classes, most in early stages of development, and few are sponsored by large pharmaceutical companies.

An Analysis of Follow-On Development in New Drug Classes, January 1986-June 2018.

Follow-on drugs-new medicines approved within an established drug class-provide incremental treatment improvements, additional choices for clinicians and patients, and potential price competition. We examine the timing, quantity, and product characteristics of within-class drug approvals for new drug classes approved by the US Food and Drug Administration since January 1986. We find that nearly two-thirds of first-in-class drugs do not face a subsequent follow-on product. Follow-on innovation within a drug class was more common and occurred more rapidly in the 1990s than during the 2000s. We also find that fewer drug classes have multiple competitors entering the market during the 2000s. First-in-class drugs treating rare disorders experienced lower rates of follow-on entry than drugs treating common medical conditions. The decreased pace of follow-on development likely results from greater industry focus on rare diseases and increasing reimbursement pressure on products lacking clear advantages over existing products.

Scientific and regulatory reasons for delay and denial of FDA approval of initial applications for new drugs, 2000-2012.

IMPORTANCE: Some new drug applications fail because of inadequate drug performance and others are not approved because the information submitted to the US Food and Drug Administration (FDA) is unsatisfactory to make that determination. Resubmission of failed applications is costly, delaying marketing approval and the availability of new drugs to patients. OBJECTIVE: To identify the reasons that FDA marketing approval for new drugs was delayed or denied. DESIGN, SETTING, AND PARTICIPANTS: A retrospective review of FDA documents and extraction of data were performed. We examined all drug applications first submitted to the FDA between 2000 and 2012 for new molecular entities (NMEs), which are active ingredients never before marketed in the United States in any form. Using FDA correspondence and reviews, we investigated the reasons NMEs failed to obtain FDA approval. MAIN OUTCOMES AND MEASURES: Reasons for delayed FDA approval or nonapproval of NME applications. RESULTS: Of the 302 identified NME applications, 151 (50%) were approved when first submitted and 222 (73.5%) were ultimately approved. Seventy-one applications required 1 or more resubmissions before approval, with a median delay to approval of 435 days following the first unsuccessful submission. Of the unsuccessful first-time applications, 24 (15.9%) included uncertainties related to dose selection, 20 (13.2%) choice of study end points that failed to adequately reflect a clinically meaningful effect, 20 (13.2%) inconsistent results when different end points were tested, 17 (11.3%) inconsistent results when different trials or study sites were compared, and 20 (13.2%) poor efficacy when compared with the standard of care. The frequency of safety deficiencies was similar among never-approved drugs compared with those with delayed approval (43 of 80 never approved [53.8%] vs 37 of 71 eventually approved [52.1%]; difference, 1.7% [95% CI, -14.86% to 18.05%]; P = .87). However, efficacy deficiencies were significantly more frequent among the never-approved drugs than among those with delayed approvals (61 of 80 never approved [76.3%] vs 28 of 71 eventually approved [39.4%]; difference, 36.9% [95% CI, 20.25% to 50.86%]; P < .001). CONCLUSIONS AND RELEVANCE: Several potentially preventable deficiencies, including failure to select optimal drug doses and suitable study end points, accounted for significant delays in the approval of new drugs. Understanding the reasons for previous failures is helpful to improve the efficiency of clinical development for new drugs.