藥品研發歷程事件對股價變動影響：以Pfizer藥廠為例

Abstract

全球藥品市場規模龐大且逐年增加，加上近年人們對於藥品安全及醫療效果要求提高，藥品審核程序增加，使得藥品研發過程對製藥公司益顯重要，因此，本研究將探討藥品研發過程中所造成的股價波動，了解股價否有異常報酬率的情形。本研究探討:（一）檢視Pfizer藥廠在藥品研發過程中發生的「事件」是否會造成股票變動；（二） 檢視Pfizer藥廠在研發過程中發生的「事件」是否與其競爭者有連動關係；（三）以Pfizer藥廠在藥品研發過程中發生的同一「事件」，官方資料庫事件公開日與大眾媒體的事件報導日，比較兩者對Pfizer藥廠股價的表現。本文將資料來源分為兩大類，運用美國食品藥品監督管理局橘皮書（FDA orange book）、美國臨床資料庫以及Web of Science作為官方資料來源，華爾街日報報導作為大眾媒體資料來源，蒐集其創立日期至2018年12月31之公開日期，透過使用事件研究法探討專利核准與到期日、臨床試驗訊息發布日、論文發表日、FDA批准新藥核准日以及競爭者對藥廠的訴訟判決日之股價異常報酬率之波動。研究結果發現，Pfizer藥廠的股價在受到大眾媒體報導前，會受到藥品核准事件、訴訟勝訴事件與訴訟和解事件的影響，且沒有發現競爭者的股價與Pfizer藥廠有連動關係，此外，針對同一事件，官方資料庫與大眾媒體報導時間差不一致。本文之研究結果可幫助投資人進行相關議題之股票的投資參考，並協助藥廠進行藥品研發歷程中的資源分配。

The circulation of money of the global medicine market is large-scale and growing year by year. In addition, the requirement for high quality medicines and the procedure for verifying medicines’ quality becoming complicated in recent years make medicinal research and development more important for pharmaceutical companies. In order to find out the fluctuations of shares during the medicinal research and development process, this study adopts an event study methodology to capture the abnormal return resulted from the specific announcement of event. In this study, I choose Pfizer as my research subject because Pfizer is the pharmaceutical company which has the best sales performance in 2018. This study aims to: 1) examine whether the events happened during the medicinal research and development process would affect Pfizer’s shares or not; 2) examine whether the events happened during the medicinal research and development process correlate to other pharmaceutical companies or not; 3) compare the fluctuations caused by the event dates written in the official databases and in the mass media. The events which are chosen to be the independent variables in the medicinal development processes include the patent application dates, the patent expiration dates, the clinical trial announcement dates, the article publication dates, the FDA drug license approval dates and the trial judgment dates for the lawsuits with competitors. The events data are collected from the official databases which include the FDA Orange Book, clinicaltrials.gov and Web of Science, and from the mass media which include the Wall Street Journal. The data’s time range is from the date when the data sources established to December 31, 2018.This study shows, the patent application dates and the trial judgment dates for the lawsuits with competitors would affect Pfizer’s shares before the mass media report, but other competitor’s shares would not correlate with Pfizer’s. Besides, the Wall Street Journal and other data sources have time gap while reporting the same events. This study could be an indicator to help investors to invest in global stock market and to help pharmaceutical companies to draw up a medicinal research and development strategy and to make a good resource allocation in the working process.