Stone Four Pharmaceutical Group (02005): Signs Letter of Intent for Potential Collaboration with Longhai Pharmaceutical on Four Biologically Similar Drugs.

Zhitong Finance News APP, Sisoy Group (02005) announced that on June 5, 2026, its wholly-owned subsidiary Shijiazhuang Siyao Co., Ltd. has signed an intention letter with Hebei Longhai Pharmaceutical Co., Ltd. (Longhai Pharmaceutical) regarding the potential cooperation on four biosimilar drugs: (1) Ustekinumab, (2) Dupalumab, (3) Abexip Injection, and (4) Ilumab.