• Comparable clinical efficacy and safety in Treatment Period 2 (TP2, Week 24-48) is maintained after switch from reference tocilizumab to TOFIDENCE (BAT1806/BIIB800)
• Phase 3 clinical data in totality demonstrates biosimilarity between TOFIDENCE (BAT1806/BIIB800) and reference tocilizumab before and after switching.^1,2

Guangzhou, China– August 2024 – Bio-Thera Solutions, Ltd. today announced, in collaboration with Biogen, the publication in the journal Arthritis Research & Therapy of results from Treatment Period 2 (TP2; study weeks 24-48) of a Phase 3 clinical study evaluating BAT1806/BIIB800, an approved biosimilar to Actemra^?/RoActemra^?3 (tocilizumab). BAT1806/BIIB800 is currently commercialized under the brand name TOFIDENCE^TM4.

In the Phase 3, multicenter, multiregional, double-blind, active-controlled, clinical equivalence study, participants with active rheumatoid arthritis (RA) despite treatment with methotrexate were randomized (1:1:2) to intravenous (iv) administration of 8 mg/kg reference tocilizumab (TCZ) every 4 weeks to week 48 (TCZ group), or TCZ to week 24 followed by BAT1806/BIIB800 to week 48 (TCZ to BAT1806/BIIB800 group), or BAT1806/BIIB800 to week 48 (BAT1806/BIIB800 group)^1,2. Efficacy in TP2 of the study was evaluated using American College of Rheumatology (ACR) response criteria (ACR20/50/70) and change from baseline in Disease Activity Score on 28 joints (DAS28)². Pharmacokinetics, safety, and immunogenicity were also evaluated. TP2 analysis also assessed the possible impact of a single treatment switch from TCZ to BAT1806/BIIB800 after week 24, reflecting clinical practice where multiple treatment switches occur.

Results from TP2 of the Phase 3 study demonstrated maintenance of comparable clinical efficacy, safety, immunogenicity and PK following switch to BAT1806/BIIB800 from TCZ, in patients with Rheumatoid Arthritis and an inadequate response to methotrexate.

“We are pleased to publish the switching data of TOFIDENCE (BAT1806/BIIB800) from reference tocilizumab that strongly supports its biosimilarity to tocilizumab for a long-term period in treating patients with active rheumatoid arthritis and an inadequate response to MTX,” said Dr Xiaolei Yang, Executive Medical Director for Rheumatology and Immunology at Bio-Thera. “We hope the study results help allay any concerns over safety and efficacy of TOFIDENCE (BAT1806/BIIB800) for use in patients who were previously treated with reference product.”

Bio-Thera Solutions, Ltd. and Biogen entered into a commercialization and license agreement to develop, manufacture and commercialize TOFIDENCE (BAT1806/BIIB800) on April 8^th, 2021. Biogen has exclusive regulatory, manufacturing and commercial rights to TOFIDENCE (BAT1806/BIIB800) in all countries excluding China (including Hong Kong, Macau and Taiwan).

BAT1806/BIIB800 TP2 Analysis

Of 621 randomized participants, 577 (92.9%) completed Treatment Period 1 (TP1, Week 0-24) and entered TP2 (TCZ: N = 145 [93.5%]; TCZ to BAT1806/BIIB800: N = 142 [92.2%]; BAT1806/BIIB800: N = 290 [92.9%])^1,2. Proportions of ACR20 responders were similar between treatment groups throughout TP2 (87.8%, 90.3%, and 90.4%, respectively, at week 48), as were proportions of ACR50 and ACR70 responders, and reduction in DAS28. Drug trough levels and antidrug antibody incidences were comparable between the treatment groups. Adverse events were balanced across the treatment groups and no fatal events were reported. In TP2, efficacy, safety, immunogenicity, and pharmacokinetic profiles were comparable between the TCZ, TCZ to BAT1806/BIIB800, and BAT1806/BIIB800 groups. These longer-term findings reinforce the results reported for TP1 and further support biosimilarity.

About Bio-Thera Solutions

Bio-Thera Solutions, Ltd., a leading innovative, global biopharmaceutical company in Guangzhou, China, is dedicated to researching and developing novel therapeutics for the treatment of cancer, autoimmune, cardiovascular, eye diseases, and other severe unmet medical needs, as well as biosimilars for existing, branded biologics to treat a range of cancer and autoimmune diseases. As a leader in next generation antibody discovery and engineering, the company has advanced multiple candidates into late-stage development, including four approved products: QLETLI^?5 and BETAGRIN?(Bevifibatide Citrate Injection) in China, and TOFIDENCE/ BAT1806 and Avzivi^?6 / Pobevcy^?7 in the US, EU and China. In addition, the company has more than 20 promising candidates in clinical trials, focusing on immuno-oncology in the post-PD-1 era and targeted therapies such as ADCs. For more information, please visit 9izixun.cn/en/ or follow us on Twitter (@bio_thera_sol) and WeChat (Bio-Thera).

Bio-Thera Cautionary Note Regarding Forward-Looking Statements

This news release contains certain forward-looking statements relating to BAT1806 or the product pipelines in general of Bio-Thera Solutions. Readers are strongly cautioned that reliance on any forward-looking statements involves known and unknown risks and uncertainties. The forward-looking statements include, among others, those containing “could,” “may,” “should,” “will,” “would,” “anticipate,” “believe,” “plan,” “promising,” “potentially,” or similar expressions. They reflect the company’s current views with respect to future events that are based on what the company believes are reasonable assumptions in view of information currently available to Bio-Thera Solutions and are not a guarantee of future performance or developments. Actual results and events may differ materially from information contained in the forward-looking statements as a result of a number of factors, including, but not limited to, risks and uncertainties inherent in pharmaceutical research and development, such as the uncertainties of pre-clinical and clinical studies, challenges in obtaining regulatory approvals, manufacturing, marketing, competition, intellectual property, product efficacy or safety, changes in global healthcare situation, changes in the company’s financial conditions, and changes to applicable laws and regulations, etc. Forward-looking statements contained herein are made only as of the date of their initial publication. Unless required by laws or regulations, Bio-Thera Solutions undertakes no obligation to publicly update any forward-looking statement, whether as a result of new information, future events, changes in the company’s views or otherwise.

1. Leng X, Leszczynski P, Jeka S, et al. Comparing tocilizumab biosimilar BAT1806/ BIIB800 with reference tocilizumab in patients with moderate-to-severe  rheumatoid arthritis with an inadequate response to methotrexate: a phase  3, randomised, multicentre, double-blind, active-controlled clinical trial. Lancet  Rheumatol. 2024;6(1):e40-50

2. Leng X, Leszczynski P, Jeka S, et al. A phase 3, randomized, double-blind, active-controlled clinical trial to compare BAT1806/BIIB800, a proposed tocilizumab biosimilar, with a tocilizumab reference product in participants with moderate-to-severe rheumatoid arthritis with inadequate response to methotrexate: treatment period 2 analysis (week 24 and week 48). Manuscript in review

3. Actemra? / RoActemra? is a registered trademark of Chugai Seiyaku Kabushiki Kaisha Corp, a member of the Roche Group

4. TOFIDENCE? is a trademark of Biogen

5. QLETLI? is a registered trademark of Bio-Thera Solutions, Ltd.

6. Avzivi? is a registered trademark of Sandoz AG

7. POBEVCY? is a registered trademark of Bio-Thera Solutions, Ltd.