Inadequate Efficacy of Biologics for Treating Proximal Ileal Lesions in Crohn's Disease; A Prospective Multicenter Study

Kento Takenaka, Tadakazu Hisamatsu, Taku Kobayashi, Hironori Yamamoto, Naoki Ohmiya, Ryohei Hayashi, Katsuyoshi Matsuoka, Masayuki Saruta, Akira Andoh, Norimasa Fukata, Kenji Watanabe, Hiroyuki Imaeda, Fumihito Hirai, Takayuki Matsumoto, Akihiro Hirakawa, Tomonori Yano, Minoru Matsuura, Ryuichi Okamoto, Kazuo Ohtsuka, Mamoru Watanabe^*