生物学的製剤の利点と欠点

Advantage and disadvantage of biologics for rheumatic diseases

生物学的製剤とは，生物が産生する蛋白質を利用した製剤である．生物学的製剤は標的分子に高親和性を有し，病態にかかわる分子の機能を制御する結果，関節リウマチ(RA)をはじめとする多くの自己免疫疾患に有効であることが明らかとなった．生物学的製剤は，有効性が高い，複数の疾患に対して有効，臓器毒性が低い，といった利点がある．一方，経口投与ができない，コストが高い，抗製剤抗体産生による効果減弱，特異な副作用などの欠点がある．本邦ではRA治療薬として，TNF(tumor necrosis factor)阻害薬(インフリキシマブ，エタネルセプト，アダリムマブ)，IL-6(interleukin-6)阻害薬(トシリズマブ)，T細胞抑制薬(アバタセプト)が用いられており，関節炎の軽減と骨破壊抑制に優れた効果を発揮している．

Biologics is defined as a drug synthesized from living organisms and their products.　They are efficacious for rheumatic diseases by binding to their target molecules with high avidity/affinity and strongly inhibiting their function.　They have advantages such as superior efficacy in many diseases to previous drugs, and have less toxicity.　The disadvantage includes parenteral administration, high cost, attenuation of efficacy by neutralizing antibody, and their intrinsic or specific adverse effects.　For treatment of RA, tumor necrosis factor (TNF) inhibitors, an interleukin-6 (IL-6) inhibitor, and a T cell inhibitor are available in Japan.　These biologics significantly ameliorate signs and symptoms of arthritis and prevent progression in joint destruction of patients with RA.