Dietary supplements: how they are used and regulated.
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Overall use of nutrient and botanical dietary supplements (DS) has increased for years across all major categories. Many DS are simply taken as part of a healthy lifestyle, but some are used to reduce risk of or modulate risk factors for specific chronic diseases, such as heart disease (vitamin E, folic acid, garlic), cancer (selenium, vitamin E, garlic) and certain birth defects (folic acid). Other DS are used for short-term benefits such as sleep management (valerian, melatonin) and enhanced physical performance (pyruvate, creatine). DS are regulated under food law, but with certain provisions that apply only to DS. Thus, DS are eligible for Food and Drug Administration (FDA)-authorized health claims under the Nutrition and Labeling Education Act (NLEA). Health claims have already been authorized for folic acid and calcium, but not for several others. In 1994, when the Dietary Supplement Health and Education Act (DSHEA) was passed, it expanded and clarified the definition of DS, specified additional requirements for safety and provided for four types of claims of nutritional support. These include prevention of classic nutritional deficiencies, structure or function (S/F) effects, mechanisms for S/F effects and general well-being. Although S/F effects result from both foods and drugs, representation that a product will treat, cure, mitigate or diagnose a disease is reserved for drugs. Therefore, the wording of S/F claims for DS has become a difficult issue in the proposed DS labeling regulations. (+info)
13C breath tests: visions and realities.
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Breath tests have been used in research laboratories for over 25 y. Originally, the tests were based on the use of (14)C, rather than on the nonradioactive isotope, (13)C. When (13)C became widely available at a reasonable cost, research groups in the United States and Europe developed methodologies to measure (13)C abundance in samples of CO(2). The tests used a variety of substrates and measured pancreatic function, fat absorption, bacterial overgrowth and P(450) mixed-function oxidase. Thus far, the only test to be approved by the Food and Drug Administration is the (13)C-urea breath test. This manuscript describes the process by which approval is gained, and indicates the steps necessary for other tests to receive Food and Drug Administration approval. (+info)
Approval summary: gemtuzumab ozogamicin in relapsed acute myeloid leukemia.
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PURPOSE: Gemtuzumab ozogamicin (Mylotarg; Wyeth Laboratories, Philadelphia, PA) consists of a semisynthetic derivative of calicheamicin, a cytotoxic antibiotic linked to a recombinant monoclonal antibody directed against the CD33 antigen present on leukemic myeloblasts in most patients with acute myeloid leukemia (AML). In this study, we review the preclinical and clinical profiles of this immunoconjugate and the regulatory review that led to marketing approval by the United States Food and Drug Administration. EXPERIMENTAL DESIGN: From the literature and manufacturer's data, we review the activity, tolerability, and pharmacokinetics of gemtuzumab ozogamicin in preclinical and Phase I studies and its activity, efficacy, and side effects in three Phase 2 trials of 142 patients with relapsed AML. RESULTS: In Phase I studies, the major toxicity was myelosuppression, especially neutropenia and thrombocytopenia, resulting from the expression of CD33 on myeloid progenitor cells. The Phase 2 dose was 9 mg/m(2) infused i.v. over 4 h, repeated on day 14. A minority of patients experienced acute infusion-related symptoms, usually transient and occasionally requiring hospitalization. The complete response (CR) rate with full recovery of hematopoiesis was 16%. A subset of patients [CRs with incomplete platelet recovery (CRps)] was identified with blast clearance and neutrophil recovery but incomplete platelet recovery. The duration of responses of CRps appeared to be similar to those of the CRs, although the numbers were small. The question of the equivalence of these response groups was a central issue in the review of this new drug application (NDA). After considerable discussion, the Oncology Drugs Advisory Committee recommended allowing inclusion of CRps resulting in an overall response rate in the Phase 2 studies of 30%. In the subgroup of patients over 60 years of age, the overall response rate was 26%. Response duration was difficult to establish because of the high prevalence of postremission therapies. Tolerability and ease of administration may be improved compared with conventional chemotherapy, except for hepatotoxicity, with 31% of patients exhibiting abnormal liver enzymes. One patient died of liver failure in the Phase 2 trials. CONCLUSIONS: Marketing approval of gemtuzumab ozogamicin was granted on May 17, 2000 by the United States Food and Drug Administration under the Accelerated Approval regulations. Gemtuzumab ozogamicin is indicated for the treatment of patients with CD33 positive AML in first relapse who are 60 years of age or older and who are not considered candidates for cytotoxic chemotherapy. The approved dose was 9 mg/m(2) i.v. over 4 h and repeated in 14 days. Completion of the ongoing studies of gemtuzumab ozogamicin in relapsed AML and initiation of randomized clinical trials comparing the effects of gemtuzumab ozogamicin in combination with conventional induction chemotherapy to conventional chemotherapy alone on survival are mandated to confirm clinical benefit under the accelerated approval Subpart H regulations. Postmarketing reports of fatal anaphylaxis, adult respiratory distress syndrome (ARDS), and hepatotoxicity, especially venoocclusive disease (VOD) in patients treated with gemtuzumab ozogamicin, with and without associated hematopoietic stem cell transplantation (HSCT), have required labeling revisions and the initiation of a registration surveillance program. Tumor lysis and ARDS have been reported in patients with leukocytes above 30,000/ml treated with gemtuzumab ozogamicin; therefore, the reduction of leukocyte counts to below 30,000/ml is recommended prior to treatment. Patients should be carefully monitored for acute hypersensitivity, hypoxia, and delayed hepatotoxicity following treatment with gemtuzumab ozogamicin. (+info)
Evaluation of the United States Food and Drug Administration-approved scoring and test system of HER-2 protein expression in breast cancer.
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PURPOSE: The purpose of this study was to investigate the prognostic significance of assessment of human epidermal growth factor receptor (HER)-2 oncogene protein overexpression of breast cancer tissue by the United States Food and Drug Administration (FDA)-approved HercepTest and grading system (negative, 0 or 1+; weakly positive, 2+; strongly positive, 3+). Furthermore, results of the HercepTest were correlated with immunohistochemical results obtained using different antibodies and protocols and with HER-2 oncogene gene amplification assessed by fluorescence in situ hybridization (FISH). EXPERIMENTAL DESIGN: HER-2 status in 303 patients with lymph node-positive breast cancer was investigated by using a rabbit polyclonal antibody (DAKO) by conventional immunohistochemistry and by applying the HercepTest. Furthermore, the monoclonal antibody CB-11 was used in conventional immunohistochemistry and with the NexES automatic stainer, which is also under consideration for FDA approval for determination of eligibility for Herceptin therapy. Results were compared with FISH analysis performed in all 2+ and 3+ specimens (103 cases) and 104 HER-2-negative specimens. RESULTS: 3+ positive carcinomas were found in 8.9-15.7% of specimens. FISH revealed that almost exclusively 3+ positive cases were amplified, with the HercepTest and the NexES automatic stainer giving the best results. In univariate analysis, staining with the HercepTest revealed a significantly worse prognosis in 3+ cases. Also, 3+ cases were significantly associated with lower estrogen receptor levels and histological grade III tumors. CONCLUSIONS: This study shows that the results of the FDA-approved HER-2 grading and test system correlated strongly with findings in FISH. Furthermore, HercepTest proved to be of prognostic relevance. Strict adherence to the given protocols is critical. (+info)
Thiazolidinediones and liver toxicity.
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Thiazolidinediones or glitazones specifically target insulin resistance. They have proven efficacy for reducing plasma glucose levels of type 2 diabetic patients treated with diet alone, sulphonylureas, metformin or insulin. In addition, they may be associated to some improvement of cardiovascular risk profile. However, troglitazone, the first compound approved by the FDA in the US, proved to be hepatotoxic and was withdrawn from the market after the report of several dozens of deaths or cases of severe hepatic failure requiring liver transplantation. It remains unclear whether or not hepatotoxicity is a class effect or is related to the unique tocopherol side chain of troglitazone. Rosiglitazone and pioglitazone, two other glitazones, appear to have similar efficacy on blood glucose control of type 2 diabetic patients as compared to troglitazone. In controlled clinical trials, the incidence of significant increases in liver enzyme levels (ALT) was similar with rosiglitazone or pioglitazone as compared to placebo, whereas troglitazone was associated with a threefold greater incidence. In contrast to the numerous case reports of acute liver failure in patients receiving troglitzone, only two cases of severe reversible liver failure have been reported in patients treated with rosiglitazone, with a causal relationship remaining uncertain. Furthermore, no single case of severe hepatotoxicity has been reported yet with pioglitazone. While regular monitoring of liver enzymes is still recommended and more long-term data are desirable, current clinical evidence supports the conclusion that rosiglitazone and pioglitazone do not share the hepatotoxic profile of troglitazone. (+info)
Food labeling: health claims; plant sterol/stanol esters and coronary heart disease. Food and Drug Administration, HHS. Interim final rule.
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The Food and Drug Administration (FDA) is authorizing the use, on food labels and in food labeling, of health claims on the association between plant sterol/stanol esters and reduced risk of coronary heart disease (CHD). FDA is taking this action in response to a petition filed by Lipton (plant sterol esters petitioner) and a petition filed by McNeil Consumer Healthcare (plant stanol esters petitioner). Based on the totality of publicly available evidence, the agency has concluded that plant sterol/stanol esters may reduce the risk of CHD. (+info)
Gastroenterology and urology devices; effective date of requirement for premarket approval of the implanted mechanical/hydraulic urinary continence device. Food and Drug Administration, HHS. Final rule.
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The Food and Drug Administration (FDA) is issuing a final rule to require the filing of a premarket approval application (PMA) or a notice of completion of a product development protocol (PDP) for the implanted mechanical/hydraulic urinary continence device, a generic type of medical device intended for the treatment of urinary incontinence. This action is being taken under the Federal Food, Drug, and Cosmetic Act (the act), as amended by the Medical Device Amendments of 1976 (the amendments), the Safe Medical Devices Act of 1990 (the SMDA), and the Food and Drug Administration Modernization Act of 1997. (+info)
Food labeling: health claims and labeling statements; dietary fiber and cancer; antioxidant vitamins and cancer; omega-3 fatty acids and coronary heart disease; folate and neural tube defects; revocation. Food and Drug Administration, HHS. Final rule.
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The Food and Drug Administration (FDA) is revoking its regulations codifying the agency's decision not to authorize the use of health claims for four substance-disease relationships in the labeling of foods, including dietary supplements: Dietary fiber and cancer, antioxidant vitamins and cancer, omega-3 fatty acids and coronary heart disease, and the claim that 0.8 milligram (mg) of folate in dietary supplement form is more effective in reducing the risk of neural tube defects than a lower amount in conventional food. This action is being taken in response to a decision of the U.S. Court of Appeals for the D.C. Circuit invalidating these regulations and directing FDA to reconsider whether to authorize the four health claims. This action will result in the removal of the regulations but does not constitute FDA authorization of the four claims. FDA is completing its reconsideration of the claims and expects to issue decisions on all four claims by October 10, 2000. (+info)