Developing EXP-1801 as an imaging agent to quantify pain and analgesia

Expesicor, Inc., Missoula MT

Investigators

Abstract

Summary/Abstract There are currently no tools available that can objectively measure pain. Historically, pain in humans has been measured using subjective ratings to determine presence and severity. In animal models, pain is measured by semi-quantitative assays that rely on the observation of pain behaviors. Though useful, the inherently subjective nature of these measures has hampered both research and treatment efforts. Simply put, inaccurate pain measurement leads to inaccurate pain management. Overtreatment and addiction to pain medications are a continuing epidemic in the U.S. The estimated economic burden of chronic pain is estimated to exceed $600 billion. One advantage of an objective pain measuring technology is cost reduction. The average cost to treat a chronic or neuropathic pain patient is $19,000 per year. These costs are exaggerated because many patients have inadequately managed pain, which requires disproportionately more resources. A significant portion of these costs go to patients who are not experiencing substantial pain; e.g. those who abuse opioids. Another area where costs could be significantly reduced is in drug development. The average pain clinical trial cost is around $71 million. The use of a pain imaging technology would allow for objective efficacy data (both pre-clinically and in clinical trials), and reduce costs by enabling smaller sample sizes due to more homogeneous populations; i.e. with a particular ?pain signal,? and more accurate measurement of analgesic effects. We recently invented a novel positron emission tomography (PET) imaging agent that we developing as a tool to address these issues in pain care and therapy development. Although the ability of PET to detect pathological changes for (early) disease detection is widely used in cancer and neurological diseases, it has not yet been used for pain indications. We have tested this molecule in healthy rats and non-human primates and found a strong signal to background ratio in nerve tissue. Our ultimate goals are: 1) to change the evaluation of (experimental) pain therapies, and 2) the standard of care in pain assessment through molecular imaging. The proposed study is designed to determine the feasibility of our imaging agent to objectively measure pain in rodents. This will set the stage for a Phase II study that further develops this agent into a tool for quantifying pain/analgesia.