Lourdes Sosa, today’s guest blogger, is an associate professor in the department of management at the London School of Economics and Political Science.

Have new cancer drugs entered the market targeting ever-smaller portions of the total cancer patient population? If so, is this a symptom of a high-tech market phenomenon known to economists as submarket fragmentation?¹ If we accurately answer these questions, we will better understand oncology drug discovery competition and thus will offer better strategic recommendations to enhance drug discovery efficiency.

My co-authors, Prof. Roberto Fernandez (MIT Work and Organization Studies), Prof. Andrew Lo (MIT Finance), and myself, Prof. Lourdes Sosa (LSE Department of Management), set about to answer these questions more than a year ago. As we began our research, our most important first step was to identify the anticancer drugs available in the US market since the birth of chemotherapy in the 1940s. A perfect data source became the Physicians’ Desk Reference (PDR®), an annual directory of approved drugs and full prescribing information that began publication in 1947.

Our next challenge came about immediately: where could we locate an accessible repository that held the entire collection to date? Although key local libraries offered us access to a large portion of the collection in print, we found in the New York Academy of Medicine Library full access to the entire collection. Furthermore, NYAM holds the collection in microfiche format, making it easy to browse from one year to another.

Starting a year ago, we began collecting data from the NYAM Library. We are now happy to report how our study is taking shape (we are also delighted to have an avenue to thank the support of Ms. Danielle Aloia and the team of expert librarians at NYAM).

The title page and an entry from the 1949 Physicians’ Desk Reference.

The figure below shows the oncology drugs available in the US market from 1947 until 2001 (data entry is still in progress). The process to identify these drugs started with the Product Category Index of the PDR®, where all cancer-related drugs can be found. We then read the full prescription information included in the product information section of the PDR® to extract the actual indications approved per drug. This latter step allowed us to make a precise decision on whether the drug was a treatment for cancer (as opposed to a treatment for a side effect or complication), and if so, to define for which cancer indications the drug was approved.

Courtesy of Roberto Fernandez, Andrew Lo, and Lourdes Sosa.

As can be seen in the figure, there is a big change in reporting in 1970. Starting that year the Product Category Index of the PDR® reported a category titled antineoplastics that made it straightforward to identify relevant drugs. In contrast, the categorization used in 1947–1969 has categories such as multiple myeloma and breast carcinoma listed separately. More importantly, during those earlier years a vast majority of drugs listed as cancer-related were in fact general-purpose drugs such as steroids, analgesics, and diuretics, which just happened to be novelties in the market.

As mentioned, we used the full prescription information to discern between the cancer-treating drugs that constitute the core of our study and those of either general application (e.g., steroids) or symptom-relief purpose (e.g., anemia treatments). The actual population of cancer-treating drugs for us to use is the black portion of the above figure shown with the legend “treating drugs.”

Our next step (after completing this exercise to year 2013) will be to calculate an index of coverage that proxies for the percentage of all cancer patients that each drug can treat. We will eagerly report on our progress as soon as we have preliminary results to share.

Reference

1. Sutton, J. 1998. Technology and Market Structure: Theory and Structure. MIT Press, Cambridge, MA.