title: The role of positron emission tomography in the drug development of M100907, a putative antipsychotic with a novel mechanism of action.
abstract: Antipsychotic drug development has been a slow process since the discovery of chlorpromazine more than 45 years ago. Researchers identify a large number of potential compounds; screen them for antipsychotic activity in in vitro and animal test models; devise appropriate formulations; perform preclinical pharmacology, pharmacokinetic, and toxicology studies; perform healthy volunteer and then patient clinical studies; and finally negotiate with regulatory agencies for drug approval. In the United States, this process takes an average of 10 to 12 years and costs more than $500 million per approved drug. More recently, the pharmaceutical industry is benefiting from a new wave of technologic innovations that have advanced our understanding of the biology of disease processes and increased the efficiency of the research and development process. However, while these new technologies may appear to be expensive, by providing the basis for early go/no-go decisions, technologies such as PET can actually be cost-effective. To ensure that innovative drug research continues, a practical strategy (rational drug design) to evaluate drugs more efficiently in terms of both time and cost (fewer studies with fewer patients) must be developed for each new drug candidate. One of the most important and difficult steps in the drug development process is defining the dose-response relationship. Using M100907 as an example, we demonstrated that mechanism-based research promotes cost-effective drug development. The therapeutic index of M100907 was defined in phase I single- and multiple-dose tolerability studies. Nuclear imaging using PET technology was then used to confirm the mechanism of action of M100907 in the target organ (living human brain) and to target an appropriate dose range and regimen. With these data, clear go/no-go decision points could be established early within the clinical drug development process, and the selection of M100907 doses to carry forward into large-scale clinical trials in patients with schizophrenia could be narrowed.
authors.affiliation: Hoechst Marion Roussel, Inc., Bridgewater, New Jersey 08807-0800, USA.
authors.forename: S J
authors.initials: SJ
authors.lastname: Offord
authors.forename: D F
authors.initials: DF
authors.lastname: Wong
authors.forename: S
authors.initials: S
authors.lastname: Nyberg
mesh_terms: D014150:Antipsychotic Agents / Q000627:therapeutic use*; D001923:Brain Chemistry / Q000187:drug effects*; D002986:Clinical Trials as Topic; D004298:Dopamine / Q000378:metabolism; D005464:Fluorobenzenes / Q000494:pharmacology* / Q000627:therapeutic use; D006801:Humans; D010880:Piperidines / Q000494:pharmacology* / Q000627:therapeutic use; D012559:Schizophrenia / Q000188:drug therapy*; D012702:Serotonin Antagonists / Q000494:pharmacology* / Q000627:therapeutic use; D013678:Technology, Pharmaceutical; D014055:Tomography, Emission-Computed
chemical_list: D014150:Antipsychotic Agents; D005464:Fluorobenzenes; D010880:Piperidines; D012702:Serotonin Antagonists; C079049:volinanserin; D004298:Dopamine