When considering new opportunities, either through business development and licensing or by expanding a drug’s indications, brand teams need an accurate view of the potential upside. In some cases, it’s fairly easy to determine the market size using monthly or yearly prescription or sales figures. However, as therapies get more specific and nuanced, more often than not market sizing is more complex.
Anonymized, longitudinal, patient-level data monitor patients’ therapies and activity in a variety of healthcare settings, including the physician’s office, pharmacy, hospital and laboratory. From these sources, a host of information about patients, their conditions, and associated treatments is collected (patients are de-identified) and can be used to answer a plethora of questions. Market sizes can be estimated using these metrics in any combination. Some of the most commonly used factors include:
- Diagnosis, with current, past, and co-morbid conditions.
- Treatments used, including both drug and non-drug therapies.
- Patient characteristics, such as age, gender, ethnicity, and Body Mass Index (BMI).
- Lab tests and their results.
HEPATITIS C
Patients, physicians, and industry analysts alike have shown increasing interest in the hepatitis C market recently, as there are nearly two dozen drugs in development and two recent launches. Merck’s Victrelis and Vertex’s Incivek were approved by the FDA in May 2011 and introduced shortly thereafter. Victrelis and Incivek, both protease inhibitors, offer physicians new options in a market where traditional treatment was long and often unpleasant for patients. The Centers for Disease Control and Prevention (CDC) estimates that there are 3.2 million people in the United States with chronic hepatitis C infections.
Prior to the introduction of these therapies, typical treatment for hepatitis C patients was a combination of weekly pegylated interferon alfa injections (brands such as PegIntron and Pegasys) and daily oral therapy of ribavirin, which typically continued for almost a year. In studies, Victrelis and Incivek were shown to help reduce the therapy length for some patients by as much as 20 to 24 weeks. Because of this benefit, their launches were highly anticipated and many were interested in estimating the sales potential of these new brands.
In order to accurately estimate the market size and population of patients who could potentially be treated by Victrelis and Incivek, anonymized patient-level data was necessary. As interferon—typically delivered through specialty mail-order pharmacies—can be used for the treatment of other conditions (such as hepatitis B), looking at drug-use alone would yield inaccurate estimates. Instead, the volume of hepatitis C patients was estimated by using anonymized, patient-level data from prescription and medical claims data to estimate how many patients were taking interferon but had not currently nor historically taken a hepatitis B therapy.
Further refinement was needed, since Victrelis and Incivek were expected to be approved to treat only genotype 1 hepatitis C patients. There are six hepatitis C genotypes. Most patients have genotype 1, but genotype 2 and 3 are also common. To properly treat hepatitis C, physicians test their patients to determine which genotype is present. Data from these lab test results allowed further refinement of the market-size estimate. In 2010, 77% of identified hepatitis C patients had genotype 1, bringing the new drugs’ market potential down by 23% (Figure 1).
Utilizing anonymized, patient-level data allowed for the most accurate estimate of market potential, taking into account retail and non-retail drug use— including the exclusion of patients based on past therapies—and lab test results.
HYPOPARATHYROIDISM
Hypoparathyroidism is another condition in which the use of anonymized patient-level data is necessary to accurately estimate the number of potential patients. Hypoparathyroidism is a rare endocrine disorder in which the parathyroid glands are absent or produce insufficient levels of hormones that regulate the body’s calcium, phosphorus, and vitamin D levels. In many instances, this condition is caused when all or part of the parathyroid glands are intentionally or inadvertently removed during a surgical procedure.
Current treatments consist of over-the-counter and prescription calcium supplements, which can treat a range of conditions. This makes it difficult to size the market using only prescription or sales information. By using anonymized, patient-level data, however, marketers can estimate the number of patients suffering from hypoparathyroidism in two different ways. The first method used the diagnosis reported on medical claims from physician visits. It is believed that hypoparathyroidism is not always reported on medical claims, so additional steps were taken to identify more patients with the condition. In this case, the study also included patients whose medical claims listed a diagnosis of hypocalcaemia. If these patients also had related, concomitant conditions such as Addison’s disease or DiGeorge’s syndrome, this indicated that they most likely were truly suffering from hypoparathyroidism. Using this method, the market of hypoparathyroidism patients in 2008 was estimated at just over 65,000 (Figure 2).
A second method for estimating the population of hypoparathyroidism patients included the study of the patients who had medical procedures in which the parathyroid glands could be removed, leading to hypoparathyroidism. These procedures include thyroidectomy, parathyroidectomy, neck dissection, and radiation was studied. The reviewers then used the percentage of patients who made subsequent claims for hypoparathyroidism— approximately 25%—to calculate an estimated prevalence.
Market potential can be estimated in countless ways, given the wide range of information captured about patients’ treatments and characteristics and the ability to track activity over time using anonymized, patient-level data. The hepatitis C and hypoparathyroidism examples employed drug use data (both current and past), diagnoses, lab test results, and recorded procedures to more accurately identify market size. As more drugs are developed for small patient populations and/or complex conditions, the need for the greater detail provided by anonymized, patient-level data will only continue to increase.
