A Comparative Study of the Market Configuration of the Japanese Pharmaceutical Market Using the Gini Coefficient and Herfindahl-Hirschman Index

BACKGROUND

As of 2015, the Japanese pharmaceutical market was the world's third largest pharmaceutical market. Although previous studies have examined market differences in terms of market size and pricing policy, little is known about comparative market configurations. The present study provides a comparative analysis of pharmaceutical market configurations in Japan and five other markets.

METHODS

Based on data for the 100 top-selling drugs in 2014 in Japan, the United States, the United Kingdom, France, Germany, and the global market, we explored differences in market configurations using the Herfindahl-Hirschman Index, Lorenz curves, and Gini coefficients. We also investigated market trends by analyzing changes in sales, sales volume, and price.

RESULTS

The 100 top-selling drugs accounted for a lower share of the total market in Japan, France, and Germany as compared to the United States and the United Kingdom. The market deviation of the 100 top-selling drugs indicated by the Herfindahl-Hirschman Index and Gini coefficient was smallest in Japan. Sales of most of the top-100 drugs increased in all the countries studied; however, directional price changes differed by country and sales volume trend.

CONCLUSION

Our findings showed that market deviations in Japan were relatively low compared with those in other developed countries, suggesting that some of the more beneficial drugs in other developed countries obtain relatively fewer benefits from the Japanese pharmaceutical market, and some less beneficial drugs obtained more benefits.

Analyzing Upward Deviation of Actual vs Predicted Drug Sales in Japan for a Reasonable Drug-Pricing Policy

BACKGROUND

Predictions of drug sales play an important role in setting drug prices in Japan, where drug prices are highly regulated. One of 2 primary Japanese drug-pricing methodologies-the cost calculation method- refers extensively to the prediction of drug sales in establishing drug prices. Deviations from predicted sales can induce disproportionate drug prices and unexpected pharmaceutical expenditures. This study aimed to estimate the upward deviation of actual sales from predicted sales and to explore the predictors of such upward deviation.

METHODS

Estimates of upward deviation in 2015 were produced for new molecular entities (NMEs) approved in 2006-2015. To identify the predictors associated with upward deviation through binary logistic regression analyses, sales within 3 years of launch and in the predicted year in which peak sales would be reached were used.

RESULTS

Estimated upward deviation was more than 1220 billion yen in 2015 for the targeted drugs. Drugs priced by the cost calculation method or by obtaining additional indications were significantly more likely to show an upward deviation from predicted peak sales.

CONCLUSION

There is substantial upward deviation between actual and predicted drug sales in Japan. So long as drug sales predictions are used in drug price calculations, a flexible repricing system is needed to buffer unexpected pharmaceutical expenditures.

Optimal Anti-cancer Drug Profiles for Effective Penetration of the Anti-cancer Drug Market by Generic Drugs in Japan

BACKGROUND

The increased use of generic drugs is a good indicator of the need to reduce the increasing costs of prescription drugs. Since there are more expensive drugs compared with other therapeutic areas, "oncology" is an important one for generic drugs. The primary objective of this article was to quantify the extent to which generic drugs in Japan occupy each level of the Anatomical Therapeutic Chemical (ATC) classification system.

METHODS

The dataset used in this study was created from publicly available information obtained from the IMS Japan Pharmaceutical Market database. Data on the total amount of sales and number of prescriptions for anti-cancer drugs between 2010 and 2016 in Japan were selected. The data were categorized according to the third level of the ATC classification system.

RESULTS

All categories of the ATC classification system had increased market shares in Japan between 2010 and 2016. The barriers to market entry were relatively low in L01F (platinum anti-neoplastics), L01C (plant-based neoplastics), L02B (cytostatic hormone antagonists), and L01D (anti-neoplastic antibiotics) but were high in L02A (cytostatic hormones), L01H (protein kinase inhibitors), and L01B (anti-metabolites).

CONCLUSIONS

Generic cancer drugs could bring savings to Japanese health care systems. Therefore, their development should be directed toward niche markets, such as L02A, L01H, and L01B, and not competitive markets.