The Institute for Scientific Exchange, Inc. Presents:

DDI-2004

7th International Conference on Drug-Drug Interactions:

Mechanism, Prediction, Accuracy, Clinical Approaches and Novel DDI Events

June 14-16, 2004

San Diego, CA, USA

Conference Venue:  San Diego Marriott Hotel & Marina

 

 

Featuring experts from the following institutions:  Advanced Pharmaceutical Sciences, Inc.; Astex Technologies; Merck Research Labs; Millennium Pharmaceuticals, Inc.; Northeastern University; Pfizer Global R&D; RTI International; Louisiana State University; Tufts University; University of North Carolina; University of Washington; Washington State University; XenoTech LLC; The Scripps Institute

  Please visit us online at www.isciencex.com

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Planning Committee Chairs:

 

Albert P. Li, Advanced Pharmaceutical Sciences, Inc.

Magang Shou, Merck Research Labs

 

 

Monday, June 14, 2004

 

7:00 AM – 8:00 AM – CONTINENTAL BREAKFAST and REGISTRATION

 

7:00 AM – 3:30 PM – EXHIBITS

 

Session I:

DDI Evaluation in Drug Development

Chair:  Albert P. Li

 

8:00 AM – 8:45 AM

Overview:  Current Status of Drug-Drug interactions (Albert P. Li, Advanced Pharmaceutical Sciences, Inc.; Baltimore, MD) Since 1995, in vitro experimental systems have been applied towards the evaluation of drug-drug interactions.  Since then, there are evidence supporting that in vitro systems are adequate in the prediction of DDI potential.  However, examples exist for both under- and over-estimation of drug-drug interactions.  Concepts explaining the errors in in vitro: in vivo extrapolation will be described and suggestions for more accurate approaches will be made.  The approaches include the use of intact hepatocytes for enzyme inhibition studies and the use of substrates more relevant to humans in vivo.

 

8:45 AM – 9:30 AM

Use of In Vitro Approaches to Evaluate Potential Clinical Drug-Drug Interactions (Lawrence L. Gan, Millennium Pharmaceuticals, Inc.; Cambridge, MA) Adverse drug reaction (ADR) as a result of inhibition and/or induction of drug metabolizing enzymes (e.g. CYP3A4) and/or drug transporters (Pgp and MRP2) by co-administered drugs is a key safety and efficacy concern in the health care community.  Various in vitro systems have been developed during recent years to evaluate the potential of drug candidates to inhibition and/or induce drug metabolizing enzymes or transporters prior to clinical development.  Computer modeling of in vitro data to project/predict clinical drug drug interactions (DDI) has also been attempted lately.  Examples of these approaches as well as the limitations will be discussed. 

 

9:30 AM – 9:45 AM – BREAK

 

9:45 AM – 10:30 AM

Strategies to Reduce Propensity of Toxicological Drug-Drug Interaction in Drug Discovery (Weichao Chen, Ph.D., Merck & Co., Inc. San Diego, CA) Toxicity of drug candidates is one of the major problems facing the pharmaceutical industry. In some cases, metabolic drug-drug interactions can lead to serious toxicological consequences in humans by increasing the formation of toxic metabolites. For example, CYP2E1 inducers would increase the risk of hepatotoxicity of acetaminophen and halothane through increased metabolic bioactivation. Strategies to avoid propensity of toxicological drug-drug interaction in drug discovery will be presented.

 

10:30 AM – 11:15 PM

In vivo Probes and Clinical Assessment of CYP3A Drug Interactions (Evan Kharasch, University of Washington; Seattle, WA) Cytochrome P450s of the 3A family (CYP3A) are the most clinically significant enzymes in human drug metabolism.  CYP3As metabolize 50%of drugs and are major determinants of first-pass and systemic clearances. CYP3A activity exhibits marked interindividual differences, due to variable CYP3A4 expression, CYP3A5 genetic polymorphism, and CYP3Asusceptibility to drug interactions.  A major drug development and clinical imperative is determining drug influence on CYP3A activity, drug interactions, and resulting alterations in drug effects. This lecture will critically review current in vivo probes for clinical CYP3A assessment.

11:15 AM – 12:00 PM

Role of Regulatory Affairs in Drug-Drug Interactions Studies (Romi Singh,  Merck Research Labs; Blue Bell, PA) Drug-drug interactions of NCEs are closely scrutinized by the regulatory agencies as part of drug approval/registration process.  Various regulatory guidances from key regulatory bodies (e.g., FDA, EMEA) will be presented and discussed.  Timing and implications of conducting such studies will be considered and evaluated.

 

12:00 PM – 1:30 PM – LUNCH

 

1:30 PM – 2:15 PM

CYP Induction-Mediated Drug Interactions: Clinical Implications (Jiunn H. Lin, Merck Research Laboratories; West Point, PA) In drug therapy, there are two major concerns with respect to CYP induction. Firstly, induction may cause a reduction in therapeutic efficacy by decreasing systemic exposure as a result of increased drug metabolism. Secondly, induction may create an undesirable imbalance between toxification and detoxification as a result of increased formation of reactive metabolites.  In the presentation, the possible pharmacokinetic and toxicological consequences of enzyme induction will be discussed.

 

2:15 PM – 3:00 PM

Industry Perspective on the Conduct of In Vitro Drug-Drug Interaction Studies (Gondi Kumar, Amgen, Inc.; Thousand Oaks, CA) Pharmaceutical industry has recently published a perspective describing a minimal best practice for in vitro and in vivo pharmacokinetic drug-drug interaction studies targeted to drug development, and to define a data package that can be expected by regulatory agencies in compound registration dossiers.  The goal was also to achieve consistency in quality and predictability of drug-drug interaction studies but not to limit innovation and experimental approaches.  This talk will focus on the conduct of in vitro drug-drug interactions. 

 

3:00PM – 3:15 PM – BREAK

 

3:15 PM – 3:45 PM

PANEL DISCUSSION:  DDI and Drug Development – Successes and Challenges (Chair:  Albert Li)

 

Session II:

 New Tools for DDI Evaluation

Chair:  Scott Obach

 

3:45 PM – 4:30 PM

Drug-Drug Interactions Involving Membrane Transporters in the Kidney (Joanne Wang, University of Washington; Seattle, WA) The kidney is a major excretory organ for eliminating drugs and drug metabolites.  In the kidney, many drugs undergo active secretion and reabsorption processes that often involve complex transport systems.  Drug-drug interactions at the renal transport sites have long been recognized.  Recent identification and characterization of various membrane transporters in the renal epithelium not only shed light on the basic mechanisms of renal drug elimination processes but also hold promise for predicting drug-drug interactions in the kidney. 

 

4:30 PM – 5:15 PM

P450 Crystal Structure for the Modeling of P450-Drug Interactions (Pamela Williams, Astex Technology; Cambridge, UKThe mammalian cytochrome P450 proteins are a family of membrane-associated haem-containing proteins which play a major role in the recognition and metabolism of numerous and diverse xenobiotics such as drug molecules. Despite significant efforts, the molecular basis of drug recognition by human cytochrome P450 proteins has remained elusive. Here we describe the first crystal structure of a human cytochrome P450 protein, CYP2C9, both in an unliganded form and in complex with the anti-coagulant drug warfarin. The structure defines unexpected molecular interactions between CYP2C9 and warfarin and reveals the location of a novel binding pocket. The binding mode of the warfarin molecule suggests that the CYP2C9 protein may invoke an allosteric mechanism during its biological function. The discovery of this binding pocket also proposes a hitherto unknown mechanism for the CYP2C9 protein to simultaneously accommodate multiple ligands during its biological function, and provides a molecular basis to understand the complex phenomena of drug-drug interactions. These crystal structures of CYP2C9 provide insights into the principles of substrate binding for these complex and promiscuous enzymes.

 

5:15 PM – 6:00 PM **NEWLY ADDED SPEAKER**

Monoclonal Antibodies (Mabs) Define Cytochrome P450 Drug Metabolism (HV Gelboin, K Krausz, National Cancer Institute, Bethesda, MD) Specific inhibitory Mabs quantify the role of each human cytochrome P450 in the metabolism of a drug or NCE (new chemical entity) or xenobiotic.  We have isolated hybridoma clones that produce Mabs uniquely specific to human P450s 1A1, 1A2, 2A6, 2C8, 2C9, 2C19, 2C family (8, 9, 18, 19), 2D6, 3A4/5 and 2E1.  The Mabs are highly inhibitory (80-90%) to the enzyme activity of the target P450 and thus the amount of inhibition of the metabolism of the substrate drug incubated with human liver microsomes defines the maximum contribution of the target P450 to the metabolism of the drug.  In stark contrast to the other complex analytic systems that are selective, the Mab system is precise and specific to the target P450 and is extraordinarily simple methodology.  The in vitro microsome – Mab system defines the contribution of the target P450 to the metabolism of the substrate and identifies substrates metabolized by a single or multiple P450s and P450s catalyzing alternate metabolic pathways.  Substrates metabolized by a single P450 or thru a specific metabolic route can be used as in vivo probes.  The system can be applied to the study of polymorphic P450s, and identify the metabolic consequences of the absence of a polymorphic P450 in individual microsomes.

 

END OF DAY

 

6:00 PM – 8:00 PM - WELCOME RECEPTION

(casual attire, not mandatory, but encouraged because it’s so much fun!)

 

Tuesday, June 15, 2004

 

Session II: Continued

 New Tools for DDI Evaluation

Chair:  Scott Obach

 

7:00 AM – 8:00 AM – CONTINENTAL BREAKFAST and REGISTRATION

 

7:00 AM – 3:15 PM – EXHIBITS

 

8:00 AM – 8:45 AM

Predicting Drug Interactions in CYP 2C9 and 2C19 Mediated Reactions with Computational Models (Jeffrey P. Jones, Washington State University; Pullman WA) Models will be presented based on experimental data that can predict the affinity of substrates for 2C9 and 2C19.  These models also predict specific molecular interactions.  These molecular interactions will also be presented.  Finally, the predictive accuracy of different modeling methods will be discussed.

 

8:45 AM – 9:30 AM

PXR Modeling Toward Dialing out PXR Agonist Activity (Ying-Duo Gao; Merck Research Laboratories; Rahway, NJ) Using the recently published PXR crystal structures, compounds that showed activities on a transactivation assay were docked into the ligand binding site in the hope of developing a strategy to dial out the PXR activity. Docking of some classic CYP3A inducers, such as Rifampicin, will be discussed as well.

 

9:30 AM – 9:45 AM – BREAK

 

 

9:45 AM – 10:30 AM

Development and Validation of Research Tools for Evaluation of Drug-Drug Interactions (DDIs) Involving the Human UDP-Glucuronosyltransferase Enzymes (UGTs) (Michael Court, Tufts University; Boston, MA) Although in vitro methodologies for the evaluation of DDI potential are routinely applied to drugs that are metabolized by the P450s, such methods are less well developed for drugs that are cleared primarily by glucuronidation.  A focus of our laboratory has been to develop and validate the research tools essential to this process, including UGT isoform-selective substrate probes, chemical and antibody inhibitors, and cell-based models for the evaluation of UGT induction.  An overview of current progress will be provided.

 

10:30 AM – 11:15 AM

Immortalized and Fresh Human Hepatocytes: Use and Performance in Metabolism, Induction and Toxicity Screening (Andrew Parkinson, XenoTech, Lenexa, KS) Human hepatocytes play several key roles in preclinical drug development, including assessment of enzyme induction, cellular toxicity, drug metabolism and species comparisons.  This presentation compares fresh and cryopreserved human hepatocytes to a new human hepatocyte cell line that has the potential to solve the problem of supply and variability that restrict the use of human hepatocytes for enzyme induction and other in vitro screening.

11:15 AM – 12:00 PM

Predicting Clinical DDI Arising from CYP3A4 Induction Using In Vitro Data: Studies with the Fa2N-4 Immortalized Hepatocyte Line (Sharon L. Ripp, Pfizer Global Research & Development; Groton, CT) The Fa2N-4 human hepatocyte line, when treated with prototypical inducers, shows a robust induction of CYP3A4 mRNA and enzymatic activity. We are examining ways to use this in vitro induction data to predict clinical DDI due to CYP3A4. One possibility is to combine potency and efficacy data from Fa2N-4 cells with efficacious plasma concentrations to assess in vivo induction potential. Studies assessing the validity of this approach using prototypical inducers will be discussed.

 

12:00 PM – 1:30 PM – ISE, Inc. Sponsored Networking Lunch

Session III:

 Metabolic & Mechanistic DDI

Chair:  Magang Shou

 

1:30 PM – 2:15 PM

Metabolism-Based Drug-Drug Interactions: Utility of In Vitro Information (Ronald S. Obach, Pfizer, Inc.; Groton, CT) Over the past several years, our knowledge of mechanisms underlying drug-drug interactions has increased to the extent that we now routinely incorporate in vitro drug interaction data into drug discovery and development strategies.  Furthermore, such data can be used in drug labeling even in the absence of clinical pharmacokinetic data.  Specific details regarding the gathering and utilization of vitro drug interaction data will be discussed.  Approaches used to predict the magnitude of interactions will be described.  The relevance of seemingly unimportant experimental details in accurately predicting drug-drug interactions will be highlighted.  Furthermore, considerations of the application of “good laboratory practices” to in vitro drug-drug interaction studies will be presented.    

 

2:15 PM – 3:00 PM

In Vitro-In Vivo Correlation of Metabolism-based Drug Interaction (Magang Shou, Merck Research Laboratories, West point, PA) Attempts have been made to predict pharmacokinetic changes and drug-drug interactions from in vitro data, particularly associated with CYP inhibition and induction.  The presentation will focus on: (1) scaling of in vitro data; (2) effect of CYP modulators (inhibitors and inducers) on PK and (3) PK modeling of metabolism-based drug interactions. 

 

 

3:00 PM – 3:15 PM - BREAK

 

3:15 PM – 4:00 PM

Mechanism-Based Inactivation of CYP 3A4 by 4-Ipomeanol (Jiang Zheng, Northeastern University; Boston, MA) Our studies showed that 4-ipomeanol, a potential chemotherapeutic agent against lung cancer, produced a time- and concentration-dependent inactivation of P450 3A4.  The inhibition of P450 3A4 by 4-ipomeanol was found to be NADPH-dependent and irreversible.  Covalent binding studies demonstrated that reactive metabolites of 4-ipomeanol modified P450 3A4 but not P450 reductase.  Reactive metabolites of 4-ipomeanol were identified by use of LC/MS/MS.  4-Ipomeanol was showed as a typical mechanism-based inactivator of P450 enzymes.

4:00 PM – 4:45 PM

Evidence for the Direct Interaction of Cytochrome P450 Enzymes: How Do These Interactions Affect P450 Function (Wayne L. Backes; Louisiana State University Health Sciences Center; New Orleans, LA) P450 enzymes do not act independently, but require a 1:1 interaction with the NADPH-P450 reductase. In microsomes, P450 is in a 20:1 excess over reductase.  Therefore, particular forms of P450 must effectively compete with others for the reductase or be metabolically silent. This raises questions regarding how these enzymes are organized in the endoplasmic reticulum.  We will present evidence that one P450 can influence the metabolic behavior of another P450, and plan to discuss the potential effect on drug disposition. 

 

4:45 PM – 5:30 PM

Structural Determinants of Substrate Binding to Human Drug Metabolizing P450s (Eric F. Johnson, The Scripps Research Institute; La Jolla, CA) Experimentally determined structures of human drug metabolizing can define structural determinants of the substrate selectivity that underlies drug metabolism and drug-drug interactions.  Recently determined P450 structures that illustrate mechanisms for substrate selectivity and functional diversity will be described.

5:30 PM

Panel Discussion: Sessions 2 and 3

 

END OF DAY

 

Wednesday, June 16, 2004

 

Session IV:

Food & Herbal Medicine Drug-Drug Interactions

Chair: James Mathews

 

7:00 AM – 8:00 AM – CONTINENTAL BREAKFAST and REGISTRATION

 

7:00 AM – 11:00 PM – EXHIBITS

 

8:00 AM – 8:45 AM

Drug-Drug Interactions with Herbal Products: In Vitro Investigations with Kava and Other Herbs (James Mathews; RTI International; Research Triangle Park, NC) It is now known that herbal medicine may cause pharmacokinetic drug interaction with low molecular weight drugs.  Experimental results with Kava and other herbs will be discussed with emphasis on the chemical identities of the herbal medicine with inhibitory effects on drug metabolizing enzyme activities.  The clinical significance of the findings will also be discussed.

 

8:45 AM – 9:30 AM

Drug Interactions with Herbal Medications (Carol Collins; University of Washington; Seattle, WA) Many patients use herbal medications in conjunction with conventional medical therapies.  This presents a difficult challenge for clinicians because little information is available on potential drug-herb interactions. The first portion of my presentation will review the existing literature on drug-herb interactions. The second portion of my talk will focus on the formulation issues that complicate this issue including: contamination with heavy metals, pesticides and prescription drugs, substitution of ingredients and lack of standardization.  The audience will gain appreciation for both the scope and complexity of evaluating drug-herb interactions.

 

9:30 AM – 9:45 AM – BREAK

 

9:45 AM – 10:30 AM

The Grapefruit Juice Effect: Are Furanocoumarins Responsible? (Mary Paine, University of North Carolina; Chapel Hill, NC)

Grapefruit juice (GFJ) elevates blood levels of numerous drugs, primarily by inhibiting intestinal CYP3A4 during absorption.  In vitro evidence indicates that furanocoumarins are the major CYP3A4 inhibitors.  To test this hypothesis in vivo, the effects of a ‘furanocoumarin-free’ GFJ were compared with orange juice (control) and GFJ on the oral pharmacokinetics of felodipine.  Results indicate that furanocoumarins are indeed the major inhibitors responsible for elevating blood levels of felodipine and probably other CYP3A4 substrates that undergo extensive intestinal first-pass metabolism.

 

10:30 AM

Panel Discussion: Session 4

 

END OF CONFERENCE

 

 

About the Institute for Scientific Exchange

 

The mission of The Institute for Scientific Exchange, Inc. is to advance science via communication – (i. e. symposia, training courses, publications).  The events held by the Institute are highly selective, timely, and of the highest professional caliber.  One major goal of the Institute, as exemplified by this symposium, is to foster communication among industrial, regulatory, and academic practitioners. Please visit our web site at www.isciencex.com.

 

 

POSTER PRESENTATIONS:

 

Poster Presentations are always encouraged.  Please submit your poster abstract for approval by the organizing board by April 30th.  Poster size should be no larger than 4 feet high by 7 feet long.  Abstracts of posters will be included in the participant binder and in the ISE website.  There is no formal poster presentation scheduled.  All posters will remain displayed throughout the conference.  Please be prepared to display your poster during registration on Sunday June 13th or before the first session begins on Monday, June 14th.  Poster presenters will have ample time for discussion during breaks and the Welcome reception.

Submit posters abstracts for approval to Nola Mahaney, VP, Operations; ISE, Inc.; 5707 Calverton Street, Suite 2C; Baltimore, MD 21228 or fax at (410) 869-9560 or email file attachment to nola@isciencex.com.  Approved poster presenters are responsible for completing a conference attendance registration form (visit www.isciencex.com/register.htm) and for the shipping of the poster itself.  Please contact Nola Mahaney for any questions or concerns.  Please refer to “Travel Information” for hotel address and shipping information.

 

  

Travel Information
San Diego Marriott Hotel & Marina; 333 West Harbor Drive, San Diego, CA; 92101, USA Phone: 1-619-234-1500; Fax: 1-619-234-8678. Here, standing gloriously at water's edge, the San Diego Marriott Hotel & Marina offers a superior level of service in a lush resort setting and an atmosphere that lends itself beautifully to business and leisurely pursuits. With its ideal location adjoining the Convention Center and Seaport Village, it puts you close to San Diego's popular attractions and landmarks, providing uncommon convenience and an extraordinary experience from the moment you arrive. Two miles from San Diego International Airport.  Spectacular views of the San Diego Bay and marina.

 

Hotel Information

A limited number of rooms have been reserved at the San Diego Marriott Hotel & Marina in Beautiful downtown San Diego at a reduced conference rate of $189.00 per single room.  There is an additional charge for extra persons.  Please make your hotel reservation directly by telephone at (Phone: 1 619-234-1500; Fax: 1-619-234-8678; International Toll-Free: 1-800-228-9290.  Please ask for the “DDI-2004” block.

 

Payment

Payment may be made by check or credit card.  Checks should be made in US $, payable to Institute for Scientific Exchange, Inc.  Mail to: ISE, Inc., 5707 Calverton Street, Suite 2C, Baltimore, MD 21228, USA

 

Cancellation Policy

All cancellations are subjected to a $250.00 cancellation fee. Longer than 30 days, 100% refund (less $250.00). Less than 30 days, no refund but registration may be transferred to another person.  All refund requests must be in writing.  All refunds will be issued after the meeting has occurred. No refunds requests will be accepted after November 1, 2003. Please submit cancellation and refund requests including transferring of registration to:

 

Fax:  410-869-9560

E-mail: nola@isciencex.com

Deadline: May 16, 2004

 

Email to nola@isciencex.com or mail/fax completed form with remittance to: ISE, Inc. 5707 Calverton Street, Suite 2C, Baltimore, MD 21228, USA; FAX No:  (410) 869-9560.  Payment may be made by check in US$, payable to Institute for Scientific Exchange, Inc. or by credit card.

 

REGISTER NOW

 

DDI-2004 Conference: US $1500.00 ______________

 

SPECIAL DISCOUNT: Both DDI-2004 & **IDT-2004: US$2500.00___________

 **3rd Idiosyncratic Drug Toxicity Conference; June 16-18, 2004 at the San Diego Marriott Hotel & Marina

 

Exhibitors: US $2000.00________________________

 

Contact Nola Mahaney for Exhibitor or Sponsorship Opportunities at nola@isciencex.com, or phone (410) 869-9166); or visit www.isciencex.com/exhibitors.htm

 

Academic/Government participants will receive a 50% discount.