Japan - Tailor-made medicines may reduce costs, prevent side effects

Main Category: Cancer / Oncology
Article Date: 24 Jan 2004 - 0:00 PDT


Studies of tailor-made medicines designed to fit individual patients are progressing rapidly in Japan.

Until recently, disparities between individuals regarding susceptibility to disease and the side effects of drugs had been put down to differing 'constitutions,' without defining exactly what that term means.

The tailor-made medicine studies aim to establish what factors make an individual constitution, and to produce bespoke drugs that are both effective and side effect-free.

According to a report in the United States, about 100,000 people die from drug side effects every year in that country. More than 2 million others suffer serious but not life-threatening side effects.

The same problem appears to exist in Japan. If tailor-made medicine can be developed, the hope is that drug doses can be cut and side effects reduced.

It also may be possible to revive the development of drugs that were abandoned due to excessive side effects if scientists can gain a better understanding of individual reaction to medicines.

As part of the Education, Science and Technology Ministry's project to develop tailor-made medicine that started last year, Biobank Japan, which is being constructed in Tokyo University's Institute of Medical Science, will start operation in February.

The project is designed to store DNA samples from 300,000 people and will be one of the largest such facilities in the world.

DNA samples from about 6,000 patients suffering from 40 kinds of diseases, including cerebrovascular disorder and cancer, are sent to Biobank Japan every month from about 50 hospitals across the nation.

Security at the facility is tight. 'Important data, such as names of sample donors, are encoded twice. Entrance of a suspicious person is prevented by identification with fingerprints and iris patterns. Protection of privacy for the DNA data is perfect,' project leader Yusuke Nakamura said,

Human DNA comprises about 3 billion chemicals called bases. It is the difference between the bases that makes us all individual.

The differences are called single nucleotide polymorphisms (SNPs) and are closely involved in determining individual reactions to medicines.

The Biobank project will analyze data from 300,000 patients with a view to understanding the relations between SNPs and the 40 kinds of disease under study.

The studies shifted into high gear after the decoding of the human genome in spring last year. The project also got a boost from the availability of new computer chips capable of analyzing huge volumes of DNA data at high speed.

Even so, medical experts say it will be five years or more before tailor-made medicines become available.

Separately from the project, Nakamura and his colleagues are studying relations between SNPs and the side effects of a diabetes treatment drug and some other kinds of medicines.

They have developed a diagnosis kit to identify the 60 percent of patients for whom a particular leukemia drug will be effective. Clinical tests of the kit are due to begin soon.

Because the leukemia drug is expensive, costing a patient about 10,000 yen a day, the kit could be a major boon for patients if it identifies those people for whom the drug would be a waste of money.

The most important target of the tailor-made medicine project is cancer.

The Research Center for Cancer Prevention and Screening of the National Cancer Center plans to collect SNP data from about 50,000 patients over the coming 10 years, aiming to establish tailor-made treatment and prevention methods for the disease.

The U.S. Food and Drug Administration in November last year unveiled the draft of a new policy obliging pharmaceutical firms to submit genetic data, including SNPs, in connection with the effectiveness of new drugs for which they are seeking approval.

Under current plans, the obligation is limited to certain kinds of drugs, but medical experts say it is likely to accelerate the trend toward tailor-made medicines.

In Japan, the Health, Labor and Welfare Ministry set up a study team to examine how to use genetic information in the development and use of new drugs.

Though Japan has achieved a lot in its study of SNPs, the country's drugmakers still lag foreign rivals.

'Though companies know it is important, Japanese drugmakers are handicapped by their small size compared with Western rivals and the high hurdles in the way of clinical tests,' said Michio Oishi, director of the Kazus DNA Research Institute.

If Japanese drug makers continue to lag behind, U.S. companies may grab control of the most important part of Japan's medical industry.

Though some experts fear that tailor-made medicines will cause medical costs to rise, they also may save money if they cut dosages and reduce side effects.

Many other issues remain to be addressed, such as how to prevent leakage of SNP data and other genetic information.

But there can be no doubt that tailor-made medicines are coming. The government needs to be sure it is prepared.

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