PROBLEM TO BE SOLVED: To provide a method for administering a pharmaceutical composition, which can suppress the generation of anti-antibodies and can be used to more effectively treat IL-6 related diseases, the method being provided for solving the immunogenicity problem that 54.2% of expression of anti-SA237 antibody was found in the Phase I single subcutaneous administration study where 120 mg of SA 237, which is an antibody having a heavy chain and a light chain and is applied with a technique for reducing immunogenicity, has been administered to a healthy adult male.SOLUTION: According to the present invention, there is provided a pharmaceutical composition comprising as an active ingredient an IL-6 receptor antibody (SA237) comprising a heavy chain having a specific sequence and a light chain having a specific sequence. According to the present invention, there is also provided a method for administering a pharmaceutical composition that is a preparation for subcutaneous administration for treatment or prevention of IL-6 related disease. In the method, after a short interval dosing period in which the composition is administered three times at the interval of two weeks from the first administration at the same dosage as the usual dosage, the composition is usually administered at intervals of 4 weeks from the final administration in the short interval dosing period. Here, the usual dose is 120 mg/dose.SELECTED DRAWING: Figure 2【課題】免疫原性を低減する技術を用いられたＳＡ２３７（重鎖と軽鎖とを持つ抗体）であっても、健康成人男性を対象に１２０ｍｇのＳＡ２３７を投与した第I相単回皮下投与試験において抗ＳＡ２３７抗体の発現が５４．２％見られ、免疫原性の問題が発生していた。抗抗体の発生を抑え、より有効なＩＬ－６関連疾患の治療に用いられる医薬組成物の投与方法の提供。【解決手段】特定の配列を有する重鎖及び特定の配列を有する軽鎖を含む、ＩＬ－６受容体抗体（ＳＡ２３７）を有効成分とする、医薬組成物であって、通常投与量と同じ投与量で初回投与から２週間間隔で３回投与される短間隔投与期間を経た後、短間隔投与期間での最終投与から４週間間隔で通常投与される、該通常投与量が１２０ｍｇ／回であるＩＬ－６関連疾患の治療用又は予防用の皮下投与製剤である医薬組成物の投与方法。【選択図】図２
