Pharmaceutical Executive Europe - August 2008 - (Page 19) Pharmaceutical Executive Europe August 2008 Technology: Patient Exposure Estimation 19 Estimating Patient Exposure Vimal Pannala and Partha Chakraborty of Cognizant Technology Solutions define postmarketing patient exposure estimation and assess its impact on safety signal detection. he importance of safety signal detection has grown in recent years as part of the ongoing scrutiny of drug safety. When considering it, it is important to focus not just on the adverse event (AE) reporting rates, but also the number of patients who might have been exposed to the drug (patient exposure). While AE reporting rates may keep increasing month-on-month, it only becomes a potential safety signal when this increase is not explained by a proportional increase in patient exposure. Patient exposure data is also required for reporting in Periodic Safety Update Reports (PSURs) and other aggregate, cumulative reports capturing the safety profile of a drug, submitted in International Council of Harmonization (ICH) regions. However, while patient exposure estimation has been a regulatory requirement for some time, it is not regarded with the same level of seriousness as AE reporting rates. There is a lack of industry standard definitions and terminologies that would allow a more structured approach for patient exposure estimation. Estimation of patient exposure is a completely manual process in most pharmaceutical companies, and it is estimated only for the purpose of its inclusion in PSURs and its use in signal detection is minimal. This may lead to false positives, which could be avoided if patient exposure is accurately estimated and used in signal management. T drug manufacturing that is not accounted for when calculating the number of drug units manufactured. This data has the greatest time lag between the time of data collection (during bulk drug sales) and end user consumption. Overcoming the challenges Time lag between the time of data collection (during prescription, primary sales or bulk drug sales) and final user consumption introduces an error in patient exposure estimation as the data from above sources could be up to several months old. To overcome this, most companies extrapolate available information based on known sales/prescription trends. However, this extrapolation may not be completely accurate and some amount of statistical error does creep into patient exposure estimation. Patient exposure is often very difficult to accurately estimate in terms of number of patients exposed and hence is normally estimated in person-time. This is because patient exposure in person-months or person-years is easier to identify from available, industry-standard data sources if annual or monthly per-capita intake of a drug is known. However, in some cases (especially for single-dose drugs), patient exposure may be expressed in terms of persons exposed, whereas in the case of non-chronic drug treatments (e.g. antibiotics) it is expressed as treatment courses. However, in the case of over-thecounter drugs, where it is difficult to predict the usage pattern, patient exposure is sometimes expressed in net sales. Pharmaceutical companies sell their drugs around the world in many different ways and through various channels: under multiple trade names, through multiple partners, in multiple formulations, in multiple stock keeping units (SKUs), etc. All of these add to the complexity in accurately estimating patient exposure. There is significant scope to automate this process by integrating required data from multiple sources such as sales, financial, manufacturing and prescription databases, into a patient exposure data warehouse. This would allow for standardisation of patient exposure estimation for each drug as a pre-built report within the data warehouse. Another option would be to integrate patient exposure data into a global safety data warehouse, and automate signal detection further by using patient exposure estimates generated from pre-built reports (as outlined above) with AE reporting rate trends to determine if a signal has been generated. Data sources Data for patient exposure estimation for post-marketing comes from three sources: third-party prescription databases (such as IMS); primary sales data (from the company’s financial database that would record value of sales); and bulk drug sales to a contract manufacturer. Capturing data from these sources poses its own challenges. While prescription data is often the most accurate and has the smallest time lag between the time of data collection (at prescription) and end user consumption, such data may not always be available, is often incomplete and can be very expensive. When primary sales data is used, the available information may not account for free samples, product returns or unsold inventories lying within the retailer. There is also a significant time lag between the time of data collection (at primary sales level) to the final sale to the end consumer and end user consumption. Bulk drug sales data is often the most inaccurate measure of patient exposure, as there is wastage of active substance during http://www.cognizant.com/html/home.asp
Table of Contents Feed for the Digital Edition of Pharmaceutical Executive Europe - August 2008 Pharmaceutical Executive Europe - August 2008 Contents From the Editor News and Analysis Calendar The Calm Before the Storm Steering Pharma in Russia Built on Sand Renaissance Man IT Meets IMI Send for the Software Specialists Know Your eMarket Last Words Pharmaceutical Executive Europe - August 2008 Pharmaceutical Executive Europe - August 2008 - Pharmaceutical Executive Europe - August 2008 (Page Cover1) Pharmaceutical Executive Europe - August 2008 - Pharmaceutical Executive Europe - August 2008 (Page Cover2) Pharmaceutical Executive Europe - August 2008 - Contents (Page 3) Pharmaceutical Executive Europe - August 2008 - Contents (Page 4) Pharmaceutical Executive Europe - August 2008 - From the Editor (Page 5) Pharmaceutical Executive Europe - August 2008 - News and Analysis (Page 6) Pharmaceutical Executive Europe - August 2008 - News and Analysis (Page 7) Pharmaceutical Executive Europe - August 2008 - Calendar (Page 8) Pharmaceutical Executive Europe - August 2008 - Calendar (Page 9) Pharmaceutical Executive Europe - August 2008 - The Calm Before the Storm (Page 10) Pharmaceutical Executive Europe - August 2008 - Steering Pharma in Russia (Page 11) Pharmaceutical Executive Europe - August 2008 - Built on Sand (Page 12) Pharmaceutical Executive Europe - August 2008 - Renaissance Man (Page 13) Pharmaceutical Executive Europe - August 2008 - Renaissance Man (Page 14) Pharmaceutical Executive Europe - August 2008 - IT Meets IMI (Page 15) Pharmaceutical Executive Europe - August 2008 - IT Meets IMI (Page 16) Pharmaceutical Executive Europe - August 2008 - IT Meets IMI (Page 17) Pharmaceutical Executive Europe - August 2008 - Send for the Software Specialists (Page 18) Pharmaceutical Executive Europe - August 2008 - Send for the Software Specialists (Page 19) Pharmaceutical Executive Europe - August 2008 - Know Your eMarket (Page 20) Pharmaceutical Executive Europe - August 2008 - Know Your eMarket (Page 21) Pharmaceutical Executive Europe - August 2008 - Last Words (Page 22)
For optimal viewing of this digital publication, please enable JavaScript and then refresh the page. If you would like to try to load the digital publication without using Flash Player detection, please click here.