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Importance: Before reviewing drug applications, the US Food and Drug Administration (FDA) conducts "filing reviews" to assess whether they are complete enough for full review. If the applications are incomplete, the FDA issues refuse-to-file (RTF) letters identifying deficiencies. The FDA does not make these RTF letters public at the time of issuance. Why the FDA issues RTF letters and how often the letters and their contents are made publicly available are unknown., Objectives: To quantitatively analyze the FDA's reasons for issuing RTF letters and assess the public transparency of RTF letters and their contents., Design and Setting: This cross-sectional study analyzes RTF letters issued in response to new drug applications and efficacy supplements (applications for new indications or patient populations for already approved drugs) submitted to the FDA between January 1, 2008, and December 31, 2017. Statistical analysis was conducted in July 2019., Main Outcomes and Measures: Two types of information were extracted and cataloged from RTF letters: (1) the reasons why the FDA refused to file applications and (2) the FDA comments that, while not a basis for RTF letters, conveyed important information to applicants. The extent to which applicants publicly disclosed the FDA's refusal reasons were also assessed., Results: The study included 103 RTF letters containing a total of 644 identified FDA refusal reasons. Among the 2475 applications that the FDA received during the study time frame, 98 (4.0%) received RTF letters. Overall, 84.5% (544 of 644) of the refusal reasons were for scientific deficiencies; most reasons were related to drug efficacy and safety (196 [30.4%]) and drug quality (125 [19.4%]). The remaining 15.5% of refusal reasons (100 of 644) were for application organization deficiencies or legal issues. A total of 26.2% of the RTF letters (27 of 103) identified presubmission advice from the FDA that applicants did not follow; the most frequently ignored advice was related to clinical trial design (33.3% [9 of 27]), followed by product chemistry and manufacturing (25.9% [7 of 27]). Applicants publicly disclosed the existence of 16 of 103 RTF letters (15.5%); however, only 5.4% of applicant-disclosed reasons (35 of 644) matched the refusal reasons that the FDA had provided in the RTF letters., Conclusions and Relevance: This cross-sectional study found that the FDA refused to file applications for substantive reasons related to quality, safety, and efficacy, and applicants' disclosure of those reasons was incomplete. This work sheds light on the FDA's regulatory decision-making processes and the RTF reasons that could delay availability of therapies to patients.

Globalization of clinical research has led to an increase in clinical trials conducted outside of the United States that are submitted to the US Food and Drug Administration (FDA) in new drug applications. This article discusses the FDA's experience with these submissions in specific therapeutic areas, including the extent of this practice, differences between the effectiveness and safety outcomes of studies conducted inside and outside the United States, and the FDA's approach to acceptance of these trials.

All medications currently approved by the Food and Drug Administration (FDA) for the treatment of type 2 diabetes mellitus are indicated to improve glycemic control. Since 1995, FDA has used HbA1c as the primary basis for approval of these therapies because a reduction in blood glucose lessens the symptoms of hyperglycemia and lowering of HbA1c has been shown to reduce the risk for some of the chronic complications of diabetes. Despite evidence of clinical benefit with therapies that reduce HbA1c, concerns have been raised that some diabetes medications may increase cardiovascular risk in a patient population that is already vulnerable to cardiovascular disease. Therefore, FDA convened a public advisory committee meeting to discuss the role of cardiovascular assessment in the pre-approval and post-approval settings for medications developed for the treatment of type 2 diabetes. After considering the advisory panel's recommendations and other data, FDA published a guidance document requesting evidence showing that new treatments for type 2 diabetes do not result in an unacceptable increase in cardiovascular risk. This review article begins by summarizing the events leading up to publication of this guidance. Subsequent sections discuss the guidance itself as well as general considerations for implementing the new cardiovascular recommendations. The new approach to developing medications for the treatment of type 2 diabetes will lead to evaluation in patients more representative of those who will use these therapies, if approved, and will help healthcare providers make informed decisions when choosing a medication within the growing treatment armamentarium for type 2 diabetes.

Critics of the U.S. Food and Drug Administration (FDA) approval of the fixed combination of hydralazine hydrochloride, 37.5 mg, and isosorbide dinitrate, 20 mg, for treating heart failure in black patients have suggested that data were insufficient to distinguish treatment effects in black and white people; that distinctions based on race, rather than pathophysiology, were scientifically unreasonable; and that a "race-based" approval could be a commercial ploy to avoid a more expensive and prolonged full evaluation of a drug. The criticisms acknowledge that data supporting the approval came from a well-designed clinical trial in which self-identified black patients with heart failure who took hydralazine hydrochloride-isosorbide dinitrate with standard therapy experienced a statistically significant 43% (95% CI, 11% to 63%) reduction in mortality compared with those who took only the standard therapy. The criticisms do not always recognize that the decision to conduct the trial in only black patients reflected careful analyses of 2 previous trials in racially mixed patient populations that compared hydralazine hydrochloride-isosorbide dinitrate with placebo or with enalapril. Both trials showed little or no overall effect of hydralazine hydrochloride-isosorbide dinitrate in the mostly white patient population but hinted at a substantial effect in subsets of black patients. Perhaps most critically, the criticisms do not appreciate the urgency of strong scientific evidence of a substantial survival benefit in black patients. A serious attempt to avoid race-based approval by mandating study of a mixed population to identify a possible white patient-responder subset, particularly without a plausible hypothesis as to what that subset might be, would have required years of work, many thousands of patients, and wholly unreasonable delay in approval of a treatment whose effectiveness had been well-documented in the group for which it was intended.

Cancer causes premature death and significant, often devastating, symptoms. While prolongation of survival is an obvious end point for new cancer drug approval, the US Food and Drug Administration (FDA) has also utilized end points that evaluate patient symptoms. In this article we discuss the end points, evidence, and analyses supporting cancer drug approvals based on evaluations of tumor-related signs and symptoms. With advice from the Oncologic Drug Advisory Committee (ODAC) in the late 1970s and early 1980s, FDA determined that acceptable end points for cancer drug approval were survival or an improvement in the quality of a patient's life, e.g., an improvement in tumor-related symptoms. This article summarizes 15 FDA cancer drug approvals based on patient symptom assessments and/or physical signs (thought to represent symptomatic improvement) as the primary evidence of effectiveness. These include painful bone events (three cases), cosmetic improvement in Kaposi's sarcoma and cutaneous T-cell lymphoma (six cases), the consequences (decreased transfusions, etc.) of long-duration responses in leukemias and lymphomas (two cases), relief of pulmonary or esophageal obstruction (two cases), and one case each of symptom benefit in pancreatic cancer (also associated with survival benefit) and pulmonary symptom benefit in lung cancer. An instructive example of an individual patient benefit end point is discussed, though it did not lead to a drug approval (the cisplatin-epinephrine gel application). Improved trial designs and analysis plans may allow greater reliance on morbidity assessments to support future cancer drug approvals. Drug sponsors are encouraged to include symptom assessments in cancer clinical trials and to perform further research to improve symptom-assessment methods. The FDA routinely meets with sponsors at End of Phase 2 Meetings to discuss drug development plans and the design of phase 3 trials. We encourage sponsors to request special protocol assessments (SPA) after meeting with the FDA to get written confirmation of the adequacy of plans for assessing cancer morbidity and quality of life, including protocols, end points, statistical analysis plans, and draft case report forms.

Although radical changes in drug regulation are rare (e.g., the Federal Food, Drug and Cosmetic Act of 1938 and the 1962 amendment to the Act creating an effectiveness requirement), regulations and guidance do evolve significantly in the face of new problems and accumulating experience. Recent changes have been driven by the Food and Drug Administration Modernization Act (FDAMA), user fee legislation, the International Conference on Harmonization, recent safety related drug withdrawals, and concerns about trial ethics and investigator conflict of interest. FDAMA and guidance developed in response to it has helped circumstances in which FDA would rely on a single study to support effectiveness and the circumstances in which surrogate endpoints could support approval. An ICH Document 'Choice of control group and related design issues in clinical trials' focussed attention on the ethics of placebo controls (acceptable, even if there is existing therapy, when the placebo-treated patient will suffer no irreversible injury) and the design of 'equivalence' or 'non-inferiority' trials. There has been greatly increased attention to obtaining good dose-response information and to assessing need for modifying treatment in demographic (age, gender, race) and concomitant disease (renal or hepatic function abnormalities) subgroups, and in assessing drug-drug interactions. Other important trends are increasing reliance on non-U.S. data, increasing numbers of FDA-industry meetings during drug development, and new focus on risk assessment and risk management., (Published in 2002 by John Wiley & Sons, Ltd.)

In a study reported herein, the marketing approval dates of 214 drugs newly introduced into the world market from January 1990 through December 1994 were compared in 4 countries. The analysis reveals that the United States and the United Kingdom have similar patterns of drug availability, although the United States has a number of therapies with significant public health benefits that are not yet available in the United Kingdom. The findings also show that the United States outpaces both Germany and Japan in approving important new drugs. Various strategies adopted by the Food and Drug Administration to expedite its pharmaceutical review process, including the use of industry user fees, are described.