Dongbao Zixing (Hangzhou) Biopharmaceutical Co., Ltd., a wholly owned subsidiary of Tonghua Dongbao Pharmaceutical Co., Ltd. ("the Company" or "Tonghua Dongbao"), completed a Phase Ib pivotal clinical trial on THDBH120 injection (a dual GLP-1/GIP receptor agonist) and produced a clinical trial report. The results demonstrate that the trial has reached its primary endpoint.

Tonghua Dongbao announced that its dual GLP-1/GIP receptor agonist, THDBH120 injection, has met the primary endpoint in a Phase Ib clinical trial for weight loss. This marks a significant milestone in the Company's development of innovative GLP-1 therapies. The drug showed good safety and tolerance in overweight and obese subjects, along with a favorable pharmacokinetic profile and clear weight-loss effect. The results lay the groundwork for the ongoing Phase II trial.

Key clinical trial results:

• The drug demonstrated good safety and tolerance after multiple doses; gastrointestinal adverse effects were consistent with those of similar products.

• Three groups of subjects received a once-weekly dosing regimen of 1 mg, 1 mg, 2 mg, and 4 mg over four weeks;  a biweekly regimen of 2 mg, 4 mg, and 6 mg over six weeks; or a biweekly regimen of 2 mg, 4 mg, and 8 mg over six weeks. At the end of treatment (Week 4 or Week 6 after the first dose), the groups showed mean      reductions in body weight of 7.38%, 8.03%, and 9.36% from baseline, respectively.

• The proportion of subjects who achieved  a weight loss of at least 5% from baseline was 90% in the 1-1-2-4 mg      group, and 100% in both the 2-4-6 mg and 2-4-8 mg groups. In the 2-4-8 mg group, over half (55.6%) of      subjects experienced a weight loss of 10% or more.

• Subjects were followed for 5 to 6 weeks after treatment ended. Results showed that weight loss was sustained or      further reduced, suggesting that THDBH120 injection may support a longer dosing interval.

• Waist circumference, blood lipids,  blood glucose, and blood pressure all decreased significantly compared      with the placebo group.

THDBH120 is a core candidate in the Company's weight-loss drug pipeline. It advanced from IND approval in April 2024 to first patient dosing in the Phase II trial in January 2025, taking just over eight months. This progress reflects the Company's enhanced R&D capabilities and efficiency, underscoring its strong commitment to expanding in endocrine and metabolic therapies.

The global obesity rate has continued to rise in recent years. According to the World Obesity Federation, the global prevalence of overweight and obesity (BMI ≥25) is projected to increase from 42% in 2020 to 54% by 2035, reaching 3.3 billion people. Obesity not only reduces quality of life but is also closely associated with chronic conditions such as cardiovascular disease, diabetes, and hypertension. It is the fifth leading risk factor for death and disability worldwide. As the number of people with obesity increases, the global market for weight-loss drugs is growing rapidly.

As an innovative weight-loss drug, THDBH120 injection has enormous market potential in the future. A comparable product, Tirzepatide, the world's first dual GLP-1/GIP receptor agonist, has seen rapid sales growth since its launch. Tirzepatide for diabetes (trade name: Mounjaro) was approved by the FDA and EMA in 2022, and its weight loss version (trade name: Zepbound) received FDA approval in November 2023. According to financial reports from Lilly, the global sales of Tirzepatide amounted to USD 16.47 billion in 2024 (2023: USD 5.34 billion), representing a year-on-year increase of approximately 208%.

The Company's THDBH120 injection, as a dual-agonist targeting both GLP-1 and GIP receptors, covers both diabetes and weight loss indications and has a huge market potential. In the future development plan, the company will not only accelerate the research and development progress of THDBH120 for injection in the indications of weight loss and diabetes, but also further explore and tap the potential of the drug in other indications.

Phase Ib Clinical Trial Results of THDBH120 Injection (Dual GLP-1/GIP Receptor Agonist)

Following NMPA approval for clinical trials of THDBH120 injection, the Company, in accordance with the relevant guidelines for novel chemical drugs in China, recently completed a randomized, double-blind, placebo-controlled Phase Ib clinical trial to evaluate the safety, tolerability, pharmacokinetics, and pharmacodynamics of multiple doses of THDBH120 injection in Chinese adult patients with type 2 diabetes mellitus. The study results achieved the primary endpoint objectives. The clinical trial results show that the pharmacokinetic profile of THDBH120 in obese subjects was similar to that in healthy individuals. Its half-life is significantly longer than that of tirzepatide, which targets the same receptors. THDBH120 demonstrated good safety and tolerance after multiple doses. No subjects discontinued treatment or withdrew due to adverse events. Gastrointestinal side effects, such as nausea and vomiting, were mostly Grade 1 or 2 and consistent with those observed in similar therapies.

At the end of treatment (Week 4 or Week 6 after the first dose), the groups showed mean reductions in body weight of 7.38%, 8.03%, and 9.36% from baseline, respectively. Compared with placebo, both weekly and biweekly regimens of THDBH120 resulted in significant weight reduction (p < 0.01), with a clear dose-effect relationship. The proportion of subjects who achieved a weight loss of at least 5% from baseline was 90% in the 1-1-2-4 mg group, and 100% in both the 2-4-6 mg and 2-4-8 mg groups. In the 2-4-8 mg group, over half (55.6%) of subjects experienced a weight loss of 10% or more. Subjects were followed for 5 to 6 weeks after treatment ended. Results showed that weight loss was sustained or further reduced, suggesting that THDBH120 injection may support a longer dosing interval. In addition, waist circumference, blood lipids, blood glucose, and blood pressure all decreased significantly compared with the placebo group. These results demonstrate that THDBH120 has a favorable benefit-risk profile, supporting its continued clinical development.

About THDBH120 Injection (Dual GLP-1/GIP Receptor Agonist)

The development of peptide-based weight-loss and antidiabetic drugs increasingly focuses on multi-agonist and long-acting novel drugs. THDBH120 injection is a dual-target agonist that acts on both the glucagon-like peptide-1 (GLP-1) receptor and the glucose-dependent insulinotropic polypeptide (GIP) receptor. This drug integrates the effects of two incretins, GLP-1 and GIP, into a polypeptide monomer and improves metabolic stability through molecular design, synergistically promoting blood glucose control, weight loss, regulation of lipid metabolism, etc. It meets the clinical needs of diabetic patients who report poor effects of treatment with single molecular targets or compounded preparations. THDBH120 injection is expected to become a more long-acting blockbuster drug for treatment of diabetes and obesity.