Sorrento Announces Positive Data from Phase 3 studies of Biosimilar Antibodies, STI-001 and STI-002

Sorrento Therapeutics, Inc.

, an antibody-centric, clinical-stage biopharmaceutical company developing new treatments for cancer and other unmet medical needs, announced today that its partner, MabTech Ltd. has successfully completed Phase 3 clinical trials in China for STI-001, a biosimilar/biobetter antibody for Cetuximab (Erbitux®) and STI-002, a biosimilar/biobetter antibody for Infliximab (Remicade®). Both STI-001 and STI-002 met their primary endpoints in confirmatory, randomized, controlled, two-part Phase 3 studies. Sorrento Therapeutics, Inc. STI-001, a chimeric monoclonal antibody that binds to the epidermal growth factor receptor (EGFR) was used for treatment of EGFR-expressing metastatic colorectal carcinoma patients in combination with irinotecan versus irinotecan alone. The combination therapy showed significant improvement compared to chemotherapy alone in Overall Response Rate (ORR: 32.9% vs 12.8%) and Progress-free Survival (PFS: 5.6 vs 3.2 months) as well as longer Overall Survival (OS: 14.1 vs 13.4 months). The ORR, PFS and OS using STI-001 and irinotecan are increased significantly than previously reported in similar medical settings using Erbitux and irinotecan (32.9% vs 10%; 5.6 vs 4.0 months; 14.1 vs11.6 months).[1] During the 501 patient double-blind, randomized Phase 3 trial, STI-001 was well tolerated. Adverse events (AEs), especially Grade 3 and 4 AEs were found to be significantly fewer than those previously reported using Erbitux. It was confirmed that STI-001, which was produced using CHO cells, possesses N-Acetylneuraminic acid (NANA), whereas Erbitux made in the murine SP2/0 cell line contains N-Glycolyneuraminic acid (NGNA), which is believed to cause side effects, such immunogenicity and hypersensitivity. While it was reported that more than 10% of patients using Erbitux showed hypersensitive reaction (Grade 3/4), none was recorded in the completed Phase 3 study of STI-001. STI-002, a chimeric monoclonal antibody produced in CHO cell line binds to soluble and transmembrane forms of tumor necrosis factor α (TNFα) and inhibits TNFα binding to receptors thereby neutralizing the biological activity of TNFα. In the current Phase 3 study with 330 patients conducted in China for the treatment of rheumatoid arthritis (RA) patients, STI-002 demonstrated an improvement in RA patients' pain symptoms, functions, quality of life and inflammation markers while also inhibiting bone and joint injuries. STI-002 (3mg/kg) plus MTX demonstrated significant improvement in ACR 20, 50 and 70 (77%, 50% and 20% respectively), similar clinical efficacy reported for Remicade and biosimilars of Remicade. Notably, the immunogenicity and anti-drug antibody formation (ADA) is drastically reduced for STI-002 compared to Remicade (<5% vs ~40%). "STI-001 and STI-002 have demonstrated clinical efficacy during the confirmatory Phase 3 trials conducted in China by our partner, MabTech Ltd. Due to its novel manufacturing technologies, the products showed improved safety profile, a great benefit for patients"; said by Dr. Henry Ji, President and CEO of Sorrento. "While MabTech is applying for marketing approval of STI-001 and STI-002 in China, Sorrento Biologics, our wholly-owned subsidiary, is expediting our efforts for the development and commercialization of these products in Sorrento territory, including the North America, Europe and Japan," added Dr. Ji.