Regulation by government authorities in the United States and foreign countries is a significant factor in the development, manufacture and marketing of our proposed products and in our ongoing research and product development activities. All of our products will require regulatory approval by government agencies prior to commercialization. In particular, human therapeutic products are subject to rigorous preclinical studies and clinical trials and other approval procedures of the FDA and similar regulatory authorities in foreign countries. Various federal and state statutes and regulations also govern or influence testing, manufacturing, safety, labeling, storage and record-keeping related to such products and their marketing. The process of obtaining these approvals and the subsequent substantial compliance with appropriate federal and state statutes and regulations require the expenditure of substantial time and financial resources. Preclinical studies generally are conducted in laboratory animals to evaluate the potential safety and the efficacy of a product. In the United States, drug developers submit the results of preclinical studies to the FDA as a part of an investigational new drug application, or IND, which must become effective before we can begin clinical trials in humans. An IND becomes effective 30 days after receipt by the FDA unless the FDA objects to it. Typically, clinical evaluation involves a time-consuming and costly three-phase process.   Phase I Refers typically to closely monitored clinical trials and includes the initial introduction of an investigational new drug into human patients or normal volunteer subjects. Phase I clinical trials are designed to determine the metabolism and pharmacologic actions of a drug in humans, the side effects associated with increasing drug doses and, if possible, to gain early evidence on effectiveness. Phase I trials also include the study of structure-activity relationships and mechanism of action in humans, as well as studies in which investigational drugs are used as research tools to explore biological phenomena or disease processes. During Phase I clinical trials, sufficient information about a drugs pharmacokinetics and pharmacological effects should be obtained to permit the design of well-controlled, scientifically valid, Phase II studies. The total number of subjects and patients included in Phase I clinical trials varies, but is generally in the range of 20 to 80 people. Phase II Refers to controlled clinical trials conducted to evaluate the effectiveness of a drug for a particular indication or indications in patients with a disease or condition under study and to determine the common short-term side effects and risks associated with the drug. These clinical trials are typically well controlled, closely monitored and conducted in a relatively small number of patients, usually involving no more than several hundred subjects. Phase III Refers to expanded controlled and uncontrolled clinical trials. These clinical trials are performed after preliminary evidence suggesting effectiveness of a drug has been obtained. They are intended to gather additional information about the effectiveness and safety that is needed to evaluate the overall benefit-risk relationship of the drug and to provide an adequate basis for physician labeling. Phase III trials usually include from several hundred to several thousand subjects.   The FDA closely monitors the progress of each of the three phases of clinical trials that are conducted in the United States and may, at its discretion, reevaluate, alter, suspend or terminate the testing based upon the data accumulated to that point and the FDAs assessment of the risk/benefit ratio to the patient. To date we have conducted many of our clinical trials in Europe. Once Phase III trials are completed, drug developers submit the results of preclinical studies and clinical trials to the FDA, in the form of a new drug application, for approval to commence commercial sales. In response, the FDA may grant marketing approval, request additional information or deny the application if the FDA determines that the application does not meet regulatory approval criteria. FDA approval may not be granted on a timely basis, or at all. Furthermore, the FDA may prevent a drug developer from marketing a product under a label for its desired indications, which may impair commercialization of the product. Similar regulatory procedures must also be complied with in countries outside the United States. If the FDA approves the new drug application, the drug becomes available for physicians to prescribe in the United States. After approval, the drug developer must submit periodic reports to the FDA, including descriptions of any adverse reactions reported. The FDA may request additional studies, known as Phase IV trials, to evaluate long-term effects. In addition to studies requested by the FDA after approval, a drug developer may conduct other trials and studies to explore use of the approved compound for treatment of new indications. The purpose of these trials and studies and related publications is to broaden the application and use of the drug and its acceptance in the medical community. We will have to complete an approval process, similar to the U.S. approval process, in virtually every foreign target market for our products in order to commercialize our product candidates in those countries. The approval procedure and the time required for approval vary from country to country and may involve additional testing. Foreign approvals may not be granted on a timely basis, or at all. In addition, regulatory approval of prices is required in most countries other than the United States. We face the risk that the resulting prices would be insufficient to generate an acceptable return to us or our collaborators.