It's very difficult to develop new drugs, and the reason it's difficult to develop new drugs is because in the early stages of drug development, the drugs are very risky, and they're very expensive.
新薬の開発は とても困難なものです 難しい理由は 新薬開発の初期段階においては 薬剤のリスクは非常に高く また とても費用がかかるからです