1 / 34

Nonprescription Orlistat GlaxoSmithKline NDA 21-887

Nonprescription Orlistat GlaxoSmithKline NDA 21-887. Nonprescription and Metabolic and Endocrinologic Drugs Advisory Committees January 23, 2006 Eric Colman, MD Division of Metabolism and Endocrinology Products. The Regulation of Prescription Weight-Loss Drugs.

tegan
Download Presentation

Nonprescription Orlistat GlaxoSmithKline NDA 21-887

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Nonprescription Orlistat GlaxoSmithKline NDA 21-887 Nonprescription and Metabolic and Endocrinologic Drugs Advisory Committees January 23, 2006 Eric Colman, MD Division of Metabolism and Endocrinology Products

  2. The Regulation of Prescription Weight-Loss Drugs • Part I 1947 to 1973 • Approval of the amphetamines and the amphetamine congeners • Part II 1974 to 1995 • Short-term treatment • Part III 1996 to present • Long-term treatment

  3. Part IAmphetamines Amphetamine Congeners1947 - 1973

  4. Approval of Amphetamines and Amphetamine Congeners • 1947 – desoxyephedrine • Indication: As an adjunct to therapy of obesity • 1960 – phenmetrazine, diethylpropion, phentermine, phendimetrazine, benzphetamine • Indication: Treatment of obesity in any patient including the adolescent, geriatric, and gravid as well as special-risk situations of the cardiac, hypertensive, and diabetic

  5. Drug Efficacy Study Implementation (DESI) • 1962 Kefauver-Harris Drug Amendments • 1966 - National Academy of Sciences reviews the efficacy of all drugs approved between 1938 and 1962 • Psychiatric Drug Panel reviews efficacy of the weight-loss drugs

  6. Psychiatric Drug Panel’s Conclusions • Amphetamines and the amphetamine congeners are less-than-effective • Trials are of short duration • Effect often plateaus or diminishes after 4-6 weeks • No available evidence that the drugs alter the natural history of obesity • Need longer-term data

  7. FDA’s Response To Psychiatric Drug Panel’s Conclusions • FDA agreed that the available evidence did not support a conclusion that the amphetamines or the amphetamine congeners were effective for weight loss • Companies told to conduct adequate and well-controlled trials to demonstrate that their weight-loss drugs are effective

  8. What is Efficacy? • FDA asks: How should efficacy of weight-loss drugs be defined? • FDA’s consultants stated that efficacy should depend on the demonstration of statistical superiority of drug to placebo • The consultants explicitly declined to require biological superiority, e.g., some minimum loss in terms of percentage of excess weight • FDA’s Advisory Committee endorsed the use of statistical superiority of drug to placebo

  9. FDA’s Amphetamine Anorectic Drug Project • Meta-analysis of data from the trials FDA required manufacturers to conduct to demonstrate efficacy of the amphetamines and the amphetamine congeners • All amphetamines and amphetamine congeners including fenfluramine • 206 double-blind studies of more than 10,000 patients • Duration of studies 3 to 24 weeks; most 12 weeks or less • Patients treated with active drug “lost a fraction of a pound more a week” than those treated with placebo – differences statistically significant

  10. FDA’s Official Position on Weight-Loss Drugs in 1973 • Although effective, the weight-loss drugs have limited usefulness in the treatment of obesity • Fraction of a pound more a week lost on drug vs placebo • Weight loss plateaus early • Weight is regained after the drug is stopped • No data on the effects of the drugs on morbidity or mortality • Overriding concern about the growing abuse of the amphetamines and to a lesser extent the amphetamine congeners

  11. Part IIShort-Term Treatment 1974 - 1995

  12. Short-Term Indication Instituted “indicated in the management of exogenous obesity as a short-term adjunct (a few weeks) in a regimen of weight reduction based on caloric restriction”

  13. The 1980s • Phen-fen studies begin in early 80s • Transition from short- to long-term treatment • 1985 NIH Consensus Conference – Health Implications of Obesity

  14. 1985 NIH Consensus Conference - 1 • What is obesity? • An excess of body fat frequently resulting in significant impairment of health • 20 percent or more above desirable body weight • Body mass index (BMI) ~ > 27.2 kg/m2

  15. 1985 NIH Consensus Conference - 2 • What are the indications for weight loss? • Weight reduction should be recommended to persons with body weight of 20% or more above desirable weight (BMI ~ 27) • Weight reduction also highly desirable, even in patients with lesser degrees of obesity, in many circumstances including NIDDM, HTN, hypercholesterolemia, COPD, and osteoarthritis • ''We want the average American and his physician to know that obesity is a disease,'' said Dr. Jules Hirsch, the [consensus conference] committee chairman • Physicians should measure patients’ BMIs to assess health risk

  16. 1992 • NIH sponsors a conference on the pharmacologic treatment of obesity • Final phen-fen results published • FDA’s Division of Metabolic and Endocrine Drug Products takes over regulatory oversight of the weight-loss drugs • Obesity Drug Guidance document

  17. NIH Workshop on Pharmacologic Treatment of Obesity • Although most other chronic diseases are treated with long-term drug therapy, drugs have played essentially no role in the treatment of obesity in America • There is evidence that modest weight losses reduce complications and risk factors of obesity • State and federal regulatory controls hinder or preclude drug use for longer than a few weeks • FDA should reevaluate process by which weight-control drugs are evaluated and approved

  18. Final Phen-Fen Results Published • “Obesity could be treated the way chronic diseases like high blood pressure or arthritis are. In those diseases, drugs can be taken indefinitely to keep symptoms in check” • Dr. Albert Stunkard: “[this study] points to the way things are going to go" • Dr. Michael Weintraub: “Not for the moderately overweight. If you just want to lose 10 pounds to look better at your high school reunion, it isn't worth it"

  19. Development of FDA’s Obesity Drug Guidance Document • January 19, 20, 1995 Advisory Committee meeting • FDA official: “Biggest change we are hoping to bring about is the approval of [obesity] drugs for long-term use” • Major considerations: • Duration and size of phase 3 studies • Criteria to define efficacy of weight-loss drugs • Appropriate patient population to study

  20. 1996 FDA Draft Guidance for the Clinical Evaluation of Weight-Control Drugs - 1 • Duration and size of phase 3 studies • One year of placebo-controlled exposure in 1500 patients • Second year of open-label exposure in 200 to 500 patients • Efficacy criteria • Mean weight loss is 5% greater in drug- vs. placebo-treated patients OR • Proportion of patients losing 5% is greater in drug- vs. placebo-treated group

  21. 1996 FDA Draft Guidance for the Clinical Evaluation of Weight-Control Drugs - 2 • Patient population • BMI > 30 or > 27 with comorbidities • Criteria are to some extent arbitrary • Optimizes therapeutic risk - benefit profile by targeting patients whose baseline risk of adverse health outcomes and expected benefits of drug treatment will outweigh the known and unknown risks of drug therapy

  22. Part IIILong-Term Treatment 1996 - present

  23. Weight-Loss Drugs Approvedfor Long-Term Use • Dexfenfluramine approved in 1996 • Sibutramine approved in 1997 • Orlistat approved in 1999 • Orlistat is indicated for obesity management including weight loss and weight maintenance when used in conjunction with a reduced-calorie diet • Orlistat is also indicated to reduce the risk for weight regain after prior weight loss • Orlistat is indicated for obese patients with an initial BMI > 30 or > 27 in the presence of other risk factors (e.g., hypertension, diabetes, dyslipidemia)

  24. 1998/2000 NIH Clinical Guidelines on Overweight and Obesity - 1 • BMI classification • normal weight 18.5 – 24.9 • overweight 25 – 29.9 • obese > 30 • The rationale behind these definitions is based on epidemiological data that show increases in mortality with BMIs above 25 • The increase in mortality, however, tends to be modest until a BMI of 30 is reached

  25. 1998/2000 NIH Clinical Guidelines on Overweight and Obesity - 2 • Weight loss medications should be used only by patients who are at increased medical risk because of their weight and should not be used for "cosmetic" weight loss. • BMI > 30 or > 27 with comorbidities • Weight loss medications should never be used without concomitant lifestyle modifications • Since obesity is a chronic disorder, the short-term use of drugs is not helpful

  26. Revising FDA’s 1996 Obesity Drug Guidance - 1 • September 8, 2004 Advisory Committee meeting • Major considerations: • Size and duration of studies • Efficacy criteria • Patient population

  27. Revising FDA’s Obesity Drug Guidance - 2 • Size and duration of trials • Size should be driven by safety • Rule out adverse events with incidence rates of 1/100, 1/500, 1/1000, etc. • Continued support for one-year of placebo-controlled exposure • Efficacy criteria • Continued support for the 5% criterion

  28. Revising FDA’s Obesity Drug Guidance - 3 • Patient population • Regarding individuals with BMIs 25 - < 27 • “Little information is available concerning the health benefits of weight loss in this BMI range. Most studies of weight loss include few if any participants with BMI 25-27 and may explicitly exclude them” Katherine Flegal, PhD, Center for Weight and Health, University of California, Berkeley, September 8, 2004

  29. Revising FDA’s Obesity Drug Guidance - 4 • Patient population • Should FDA change the inclusion criteria to include subjects with BMIs of 25 - < 27 plus a comorbidity? • Majority of committee members did not support lowering BMI to 25 - < 27 • Drug treatment of subjects with BMIs 25 to 27 would require much greater assurance of a drug’s safety

  30. Guidelines for Prescription Drug Treatment of Obesity - 1 • BMI > 30 or > 27 with comorbidities • NIH Practical Guide (2000) • American Obesity Association(2005) • NAASO, The Obesity Society (ref NIH) • American Gastroenterology Association (2002) • American Association of Clinical Endocrinologists (1998) • BMI > 30 • American College of Physicians (2005)

  31. Guidelines for Prescription Drug Treatment of Obesity - 2 • American Society of Bariatric Physicians (2004) • BMI › or = 30.0 in a normal, otherwise healthy individual • BMI › or = 27.0 in an individual with associated comorbidities • Current body weight › or = 120% of a well documented, long-standing, healthy weight that the patient maintained after age 18 • Body Fat › or = 30% in females • Body Fat › or = 25% in males • Waist-hip ratio or waist circumference such that the individual is known to be at increased cardiovascular and/or co-morbidity risk due to abdominal visceral fat. • Presence of a comorbid condition or conditions aggravated by the patient’s excessive adiposity

  32. Major Themes in the Prescription Drug Treatment of Obesity - 1 • Short-term adjunctive therapy to enhance will-power to long-term adjunctive treatment of a complex, chronic disease • Defining obesity • 15 to 20% above ideal body weight • BMI > 27 - 1985 • BMI > 30 - 1995 • Defining overweight vs. obesity • BMI 25 to 29.9 vs. > 30

  33. Major Themes in the Prescription Drug Treatment of Obesity - 2 • Defining efficacy of weight-loss drugs • Achieving ideal weight • Losing 50% of excess weight • Losing 20 or 40 pounds • Statistically significant weight loss • 5-10% weight loss • Medical vs. cosmetic weight loss

  34. Major Themes in the Prescription Drug Treatment of Obesity - 3 • Medical weight loss • Long-term reduction in weight and fat mass with improvement in physical health in high-risk patients • 5-10% weight loss • Cosmetic weight loss • Short-term reduction in weight and fat mass with improvement in physical appearance in low- or zero-risk individuals • ???% weight loss • Risk vs. benefit of drug treatment

More Related