Drug Topics - October 22, 2007 - (Page 20)

20 DRUG TOPICS OCTOBER 22, 2007 www.drugtopics.com Cover Story DYNAMIC DUO Is a new effort to codevelop drugs and diagnostics just an interesting concept or the future of drug development? Heidi Belden, Pharm.D. THE NEW I t used to be that genetics referred to a class you took in college, where completing Punnett squares to determine the likelihood of inheriting a trait was all you needed to know. My, how times have changed. Today, it’s a whole new world. Genetics and how it directly relates to a patient’s response to drug treatment is revolutionizing medicine. Just within the past few months, we have seen Food & Drug Administration warnings issued for both warfarin and codeine, describing how a patient’s genetic makeup directly affects the way a drug is metabolized, the potential for adverse effects, and the dose required. The agency stopped just short of recommending that patients undergo genetic testing prior to initiating therapy in both cases. But as we gain more knowledge about biomarkers and how they aid in monitoring disease and medication use, we are likely to see big changes in the way drugs are developed, with a concept known as drug-test codevelopment gaining momentum. Parallel development of a drug and diagnostic test from the preclinical stage through to submission of a New Drug Application or Biologic License Application (NDA or BLA) is a hot topic. It calls for careful coordination, according to the FDA, but it also holds the promise of great improvements to public health. Currently, the agency is working on a strategy to give manufacturers better advice and guidance on the issue. Although examples of dual approvals are lacking, many experts believe that codevelopment may soon be the prevailing model as gene-based diagnostics continue to emerge and become increasingly important to both drug development and clinical practice. At the same time, manufacturers are won- dering exactly what it means for them. Will it increase the cost or time required to bring a new entity to market? And will codevelopment severely limit the population size able to use the drug by identifying responders, nonresponders, and those likely to experience adverse effects? Plus, if numerous biomarkers are found and tests are created, will codevelopment eventually be mandated by regulatory agencies? These are some of the questions being asked as drug-test codevelopment, abbreviated as RxDx, evolves. Two in the hand “This is a sea change in how medicine is performed,” said David Flockhart, M.D., Ph.D., chief of clinical pharmacology at Indiana University School of Medicine. He explained how treatments are given only to patients with certain characteristics and no longer are we using a one-size-fits-all approach for everyone with a particular disease. “We’d much more carefully stratify people by using drug-test combinations.” The best understood and widely appreciated example of RxDx is trastuzumab (Herceptin, Genentech), according to Flockhart, where the overexpression of the HER2/neu gene is both predictive of response to treatment with the monoclonal antibody and prognostic of a poor outcome in women with breast cancer. During development, Genentech realized that treatment would require a test that could identify this subset of patients. The company went ahead and devised the diagnostic in order to select patients for clinical trials. Genentech originally partnered with Dako Corp. to develop a test that would also be suitable for commercial use and could gain FDA approval. The combination was approved in 1998 after both companies filed Illustration: George Baquero http://www.drugtopics.com

Table of Contents Feed for the Digital Edition of Drug Topics - October 22, 2007

Drug Topics - October 22, 2007 Contents Latebreakers Legislative Victory Builds Momentum for Pharmacy Month Letters Health-System Edition R.Ph.s Brace for Payment Denial for Hospital-Acquired Conditions Topical Human Thrombin Helps Arrest Bleeding FDA Panels Fail to Set Target Levels for Renal Patients’ Hemoglobin Warning Letters Raise Patient Safety Concerns for Fentora Ending/Reversing Weight Gain Man Given Fatal Drug Overdose at Staten Island Hospital Pharmacists Playing More Important Role in Dialysis Treatment AHA President R.Ph.'s Here's How You Can Increase Your Value Premier Launches Comprehensive Quality Improvement Project FDA Approves Dexrazoxane for Treatment of Extravasation New Federal, State Reforms to Ease Disaster Relief Kinks 150 Years of American Pharmacy Ten Tips for MTM Success Independent Superstars: The Ones to Watch The New Dynamic Duo A Parkinson's Disease Primer Classified New Products Advertisers Index Viewpoint

Drug Topics - October 22, 2007

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