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MarketWatchEstimating The Cost Of New Drug Development: Is It Really $802 Million?
This paper replicates the drug development cost estimates of Joseph DiMasi and colleagues ("The Price of Innovation"), using their published cost estimates along with information on success rates and durations from a publicly available data set. For drugs entering human clinical trials for the first time between 1989 and 2002, the paper estimated the cost per new drug to be $868 million. However, our estimates vary from around $500 million to more than $2,000 million, depending on the therapy or the developing firm.
THE EXPECTED COST of developing an average drug was recently estimated by Joseph DiMasi and colleagues at $802 million per new molecular entity (in 2000 dollars).1 The enormous cost of drug development is a key component of the current debates over prescription drug prices, importation of drugs from Canada, Food and Drug Administration (FDA) review policies, and barriers to generic entry. Given the central role of the $802 million estimate in these debates, it is important to ask two questions. First, is this number an accurate estimate of the expected cost of developing an average drug? Second, even if it is accurate, what does the estimate mean? This paper independently verifies DiMasi and colleagues estimate, in "The Price of Innovation" (hereafter, DHG), using a publicly available data set on drug development. Our analysis also raises several issues that must be accounted for in interpreting the $802 million as a meaningful measure of actual drug development costs: the meaning of "average drug," the impact of firms strategic decisions, and regulatory policies effects on development costs.
DHG methodology. DiMasi and colleagues took three steps to reach their $802 million estimate. First, they randomly selected sixty-eight drugs from the proprietary Tufts Center for the Study of Drug Development (CSDD) database of investigational compounds for ten multinational pharmaceutical firms participating in a confidential survey. These survey data provide the average cost of taking a drug through each step of the drug development process. This is the actual money that the drug companies spent on the process. Second, they used the CSDD database to calculate the probability that the average drug will get to each phase. By multiplying the estimated average amount spent in each phase by the probability of getting to the phase, they calculated the expected cost of developing a drug for market. The authors then used the CSDD database to estimate the probability that a drug in Phase I would be approved and used this number to calculate the expected cost per approved drug. Third, the authors used the CSDD database to estimate the average duration for each stage in the drug development process. These durations were then used to estimate the time cost or opportunity cost of developing a drug. Our methodology. We estimated the expected cost of developing an approved drug in the same way. However, instead of using estimates from the proprietary CSDD database, we used estimates from the publicly available Pharmaprojects database. This allows others to verify our results. An important concern is that the data are likely to be less accurate than the survey data used to compile the CSDD database. The Pharmaprojects data are collected by the vendor (PJB Publications) based on press releases, academic presentations, and other public information about drugs in development. Because of this collection process, the data do not always include information on drugs in the earlier stages of human clinical trials. Although we have some concern about accuracy, we have no reason to believe that the data are biased. To estimate the cost of developing drugs with different characteristics, we assumed that the average actual cost is the same across different drug characteristics. That is to say, the estimated variation in costs across drugs with different characteristics is attributable to differences in the estimated probability of success and in the estimated duration. It is important to also be aware that different drug types might have substantially different actual costs of clinical trials. Therefore, the estimated variation in drug costs could be higher or lower, depending on whether the correlation between actual costs, success probabilities, and durations is positive or negative. As discussed below, recent work suggests that HIV/AIDS drugs have high clinical costs, which may offset cost reductions reported in this paper.2 There is some controversy over how DiMasi and colleagues calculated their cost numbers, including the use of before-tax income and different discount rates. (See the authors discussion of the issues and the references therein for more detail.) For this paper, we followed the DHG calculations.
The data used in our study contain information updated monthly on drugs in a late stage of development, covering 1989 to the present, and include drugs now in development and those that have been discontinued or withdrawn from the process.3 The recorded information includes the drugs current status, the original materials, the primary therapy, the primary indication and other indications, route of administration, and the name of the developing firm. It also includes major event dates in the life of the drug, such as entry dates in each of the phases, as well as exit and registration dates, when applicable. For this study, we limited our attention to all drugs that went into human clinical trials for the first time between 1989 and 2002 and for which we have an entry date and at least one additional piece of information after entry. Concern about dates. There is some concern about the dates available from the Pharmaprojects database. In particular, the date is often only accurate to a particular month. We have discussed these issues with the vendor, and we are confident that every effort has been made to publish accurate dates. We know of no evidence that suggests that these dates are systematically misreported. In fact, we have found that statistics based on this database are consistent with other publicly reported statistics from other databases. CSDD versus Pharmaprojects. Although both the CSDD and Pharmaprojects databases purport to include detailed information about each drugs development milestones, there are important differences.4 The drugs used in the DHG analysis are all new molecular entities (NMEs). To obtain a sample of drugs that is closer to that used in the DHG analysis, we dropped drugs that were indicated in the database as being new formulations of previously approved drugs. The CSDD sample is limited to self-originated drugs; unfortunately, the information in Pharmaprojects is not detailed enough to make the same restriction. The drugs used in the DHG analysis are drugs that first entered human clinical trials somewhere in the world after 1983. Again, unfortunately, the information in Pharmaprojects does not allow us to select on this criterion. The data set we used includes drugs that first entered one of the phases of human clinical development somewhere in the world after 1989the first year for which Pharmaprojects provides detailed and easily accessible information on drug histories. The data selected for the DHG study were all first tested in humans prior to 1994. Because of the limitations of our data, we included drugs that entered any one of the three stages by 2002. Using these criteria, our data set is much larger than the one selected from the CSDD data. Our sample includes information on 3,181 compounds, while the DHG sample has information on 538 compounds. It is not clear to us exactly which of these differences accounts for the discrepancy in sample sizes. Despite these apparent differences, the results presented here show that the two data sets provide a similar picture of success rates and durations for the average drug.
Development costs. Success rates calculated from the two data sets give somewhat similar results (Exhibit 1
There are a few things to note about our estimates. First, our phase transition probabilities were calculated by taking the drugs in Phase II, for example, that successfully moved to Phase III and dividing that number by the same number plus the number of drugs in Phase II for which development was discontinued. We assumed that currently active drugs will experience the same probabilities of success and duration as drug candidates whose projects are completed. Second, our estimate for successfully moving from Phase I to approval was calculated by simply multiplying the phase transition probabilities together. We did it this way because the data set has very few drugs with complete information for all three phases. This procedure is less efficient than using a duration model to estimate the success rates of these drugs (the approach taken by the DHG study). That approach relied on the assumption that the censored drugs will have the same probability of success, conditional on time in development, as the uncensored drugs. The approach we used in this paper does not rely on this assumption; however, the estimate could be biased if drugs with longer durations are more likely to either succeed or fail.5
Opportunity costs.
Exhibit 2
The difference is due in part to the slightly different method of calculating the phase durations. The CSDD data include both start and end dates for the phases and show that there are some overlaps as well as some gaps between phases. Unfortunately, in the Pharmaprojects data, we have only phase start dates; we therefore assumed that the end date is equal to the start date of the next phase. The durations in these data were calculated for drugs that completed each phase.7 The CSDD durations were calculated for self-originated drugs that were approved between 1992 and 1999. We estimated that the time from a new drug application (NDA) to approval is 15.8 months using data from the Orange Book matched to the Pharmaprojects database. This duration is less than the DHG estimate of 18.2 months.8
Cost comparisons.
Exhibit 3
Exhibit 4
The results suggest that there is little advantage from being large and that drug development costs vary greatly among large firms. Exhibit 4 Impact of size. It has been argued that larger companies have economies of scale and scope in drug development that might be associated with lower development costs.11 One difficulty in measuring such an effect is that large firms might be associated with successful (and lower-cost) drugs, either because such drugs tend to earn substantial revenues or because mergers and acquisitions lead to such drugs being in larger firms.12 The results suggest that this could be a problem. When an ex post measure of size (Top 10 by 2001 income) is used, the average drug from a large firm has a cost much lower than the overall average. However, when ex ante measures of size are used, the cost of the average drug from a large firm is larger than the cost for the overall average drug. These results do not support the claim that larger firms tend to produce lower-cost drugs. Drugs from firms that had the largest number of drugs in development had an average capitalized cost of $992 millionsome $124 million more than the average drug. Comparisons with previous work. These results contrast somewhat with previous work that found that drugs from small firms tend to have higher costs than drugs from larger firms.13 DiMasi and Henry Grabowski found in 1995 that this difference was the result of high preclinical spending and longer durations for drugs from small firms. One difference is that we did not account for the mixture of drugs by therapeutic category among firms. Nor did we account for differences in actual spending by firm group. Another explanation is that our study is more recent, and contract research organizations might have leveled the playing field between large and small firms.14
Variation within drug groups.
Exhibit 4 Role of strategic choice. This variation highlights an important issue in interpreting cost data. These costs are not completely exogenously determined; rather, these cost estimates are based on data that are the result of strategic behavior by the firms themselves. Therefore, although some of this variation is the result of luck or specialization in particular therapeutic categories, some might be the result of strategic choice. Firms may choose a high-risk (high-cost)/high-return strategy or a low-risk (low-cost)/low-return strategy.15
Exhibit 5
The exhibit shows that there is much variation in phase transitions and success rates. Note that although low transition probabilities reduce the expected cost of a drug, low success rates increase its cost. A little algebra shows that the second effect always outweighs the first.19 We see that drugs in development for respiratory disorders such as asthma have very low success rates (16 percent), whereas drugs in development for genitourinary disorders, which include drugs such as Viagra, have much higher success rates.
Exhibit 5
The results also give some indication that regulatory policy can help to reduce development costs. Exhibit 5
Variation by drug type. The results presented here suggest that there is considerable variation in the estimated cost of developing different drugs. The estimated expected cost of developing an HIV/AIDS drug is $479 million, while the expected cost of developing a rheumatoid arthritis drug is $936 million. DiMasi and colleagues similarly found large variation in the estimated expected development costs.24 Using the same data as in their original 1991 study, they found that capitalized clinical costs per approved drug were 25 percent below the average for anti-infectives (such as penicillin) and 75 percent above the average for nonsteroidal anti-inflammatory drugs (NSAIDs, such as Celebrex).25 Their more recent work reports variations from 13 percent above the average to 20 percent below the average. These estimated differences imply that different therapies might have different costs. For example, anticancer drugs have much higher expected durations, implying higher development costs. Other factors affecting the estimates. Another issue is that these estimates are based on observed success rates and durations of actual drugs. The concern is that these numbers are affected by many factors, including factors under the control of the firms developing the drugs. This fact makes it difficult to determine the extent to which these high measured costs really impede new drug development or reduce drug companies incentives to develop new drugs or types of new drugs. The results show that for one large pharmaceutical firm, the expected cost of developing a drug is $521 million, while for another large firm, it is $2,119 million. This difference suggests that some of the estimated costs could be attributable to the strategic decisions of the drug firms themselves. Impact of regulatory policies. The estimated cost of developing HIV/AIDS drugs suggests that regulatory policy can also have a substantive effect on the cost of drug development. In particular, the low cost estimates of developing HIV/AIDS drugs seem to be in some part the result of the short durations for these drugs, which is in part attributable to FDA policy regarding review of these drugs.26 However, as discussed above, there may be reasons to be cautious about this explanation. RECENT ESTIMATES on the cost of drug development play an important role in the current debates on drug prices, regulatory policy, generic entry, and drug importation. This paper attempts to verify the accuracy of the DHG estimate that the expected capitalized cost per approved drug is $802 million. Our estimate of $868 million suggests, if anything, that $802 million is an underestimate. However, we also found substantial variation in estimated drug costs, which suggests that policymakers should take care in using a single number to characterize drug costs and that these cost numbers are determined by a series of factors including the strategic decision making of the drug firms themselves.
Christopher Adams (cadams{at}ftc.gov) is an economist and Van Brantner is a research analyst at the Bureau of Economics, Federal Trade Commission, in Washington, D.C. This paper does not necessarily represent the views of the Federal Trade Commission (FTC) or any individual commissioner. The authors thank PJB Publications for providing and answering questions about the data; Stephen Bonventre for excellent research assistance; and their colleagues at the FTC for helpful comments and suggestions. They also thank two anonymous reviewers and the Health Affairs editorial staff. In addition, they thank Rosa Abrantes-Metz, Ana Aizcorbe, Ernie Berndt, Joe DiMasi, Mark Duggan, Richard Frank, Sean Nicholson, Chris Snyder, as well as participants at the National Bureau of Economic Research (NBER) Summer Institute and the George Washington University and Bureau of Economic Analysis (BEA) seminars for helpful suggestions. They are particularly grateful to Bill Vogt for his encouragement and suggestions. All errors are the authors own.
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