OBJECTIVES : Many biologics and some biosimilars (BS) have launched in Japan since the first biologic, insulin, was launched in 1985. However, reports on their current situation are still limited and unclear. We examined the prescriptions, volume and costs of biologics and BS.

METHODS : We performed a retrospective study using Japanese medical insurance claims and administrative database provided by Medical Data Vision (MDV) Inc., the largest commercial, hospital-based administrative database with data on all drug prescriptions (trade name/general name), their costs, and availability of generics for FY2017.

RESULTS : 118 biologics as general drug name were prescribed in Japan at a total cost of about 2 Billion USD, which represents 25.5% of total drug cost. By ATC coding (Anatomical Therapeutic Chemical Classification System), biologics were most used for “antineoplastic drugs (20 biologics)” at 41.8%, followed by “immunosuppressants (13 biologics)” at 16.6%. For 6 of the 118 biologics, BS are available in Japan, and the rates of BS use, in terms of volume, varied, from a min of 0.8% to a max of 95.6%. BS volume proportion of epoetin kappa and filgrastim, insulin glargine, infliximab, somatropine and rituximab were 95.6%, 77.2%, 48.0%, 4.2%, 3.3% and 0.8%, respectively. The latter 3 drugs were found to be used at low proportion of volume, however, they were included in the top 10 biologics in terms of costs. On the other hand, the former 3 drugs were prescribed in large amounts, while their costs were found to be low.

CONCLUSIONS : In Japan, the biologics cost was covered one-fourth of total drug cost in FY2017. For biologics with BS available, the proportion of BS use to their costs were inversely related. To control medical expenditure, we recommend that it is just as important to focus on drug costs, in addition to the prescribed volume.