- BW-40202 being evaluated in two clinical trials for the treatment of PNH and IgAN, respectively

SHANGHAI, CHINA and NEW YORK, USA –April 20, 2026—Argo Biopharmaceutical Co., Ltd. (Argo Biopharma), a clinical-stage small interfering RNA (siRNA) therapeutics company, today announced the first patient has been dosed in multiple Phase II studies of BW-40202, an investigational siRNA therapy targeting complement factor B (CFB). Each Phase II clinical trial has been designed to evaluate BW-40202 as a potential treatment for patients suffering from complement-mediated diseases paroxysmal nocturnal hemoglobinuria (PNH) and immunoglobulin A nephropathy (IgAN).

“Dosing the first patient in both of these Phase II trials marks an important step forward in Argo's mission to develop more efficacious treatment options for patients suffering from complement-mediated diseases.. Complement pathway biology is highly complex and we believe a potent and durable siRNA therapeutic has the potential to make a meaningful difference for patients." said Dr. Dongxu Shu, co-founder and CEO of Argo Biopharma.

BW-40202 is an siRNA therapeutic that targets CFB mRNA in the liver. It utilizes an RNA interference (RNAi) mechanism to suppress CFB expression, thereby reducing serum CFB protein levels and inhibiting complement alternative pathway (CAP) activity. In preclinical studies, BW-40202 demonstrated excellent purity and stability, with significant and durable suppression of serum CFB protein, effective inhibition of CAP activity, and a favorable safety profile. BW-40202 also demonstrated excellent pharmacological activity, significantly reducing serum CFB protein levels and effectively inhibiting CAP activity, with long-lasting effects and a favorable safety profile.

About Paroxysmal Nocturnal Hemoglobinuria (PNH)

Paroxysmal nocturnal hemoglobinuria (PNH) is a rare acquired hemolytic disorder characterized by complement-mediated red blood cell destruction (hemolysis), bone marrow failure and severe thrombophilia. Globally, it is estimated that approximately 10 to 20 individuals per million are living with PNH¹. Patients may experience a range of symptoms, including severe anemia, thrombosis, fatigue, hemoglobinuria, chronic kidney disease and pulmonary hypertension. Thromboembolism is the leading cause of mortality in patients with PNH, accounting for between 40% and 67% of death with known cause², impacting morbidity and life expectancy of PNH patients. siRNA therapies offer precise targeting, longer-lasting efficacy, reduced dosing frequency, and improved safety and convenience, which is a promising new approach with the potential to deliver more effective, durable, safer, and more manageable treatment options.

About Immunoglobulin A Nephropathy (IgAN)

IgA nephropathy (IgAN) is a chronic kidney disease characterized by the deposition of immunoglobulin A in the glomeruli, leading to inflammation and progressive kidney damage. As the most common type of primary glomerulonephritis worldwide, Despite current standards of care, up to 50% of patients with IgAN have progression to kidney failure within 10 to 20 years after diagnosis^3-5. Current treatment options remain limited in achieving the desired treatment goals, underscoring the need for therapies that can effectively slow disease progression and improve long-term outcomes.

About Argo Biopharma

Argo Biopharma is a clinical-stage biotechnology company committed to developing next-generation RNAi therapeutics to provide better treatment options for patients worldwide. The company has established a robust and diverse pipeline of RNAi molecule candidates targeting a wide range of indications, including cardiovascular diseases, viral infections, metabolic conditions, and specialty/rare diseases. Currently, Argo Biopharma has seven RNAi candidates in clinical development.

For more information, please visit www.argobiopharma.com.

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References:

1. Schrezenmeier, H., et al. (2020). Baseline clinical characteristics and disease burden in patients with paroxysmal nocturnal hemoglobinuria (PNH): updated analysis from the International PNH Registry. Annals of Hematology, 99, 1505–1514.
2. Hill A, Kelly RJ, Hillmen P. Thrombosis in paroxysmal nocturnal hemoglobinuria. Blood. 2013;121(25):4985-5105. doi:10.1182/blood-2012-09-311381
3. Xie J, Kiryluk K, Wang W, et al. Predicting progression of IgA nephropathy: new clinical progression risk score. PLoS One 2012; 7(6): e38904.
4. Pitcher D, Braddon F, Hendry B, et al. Long-term outcomes in IgA nephropathy. Clin J Am Soc Nephrol 2023; 18: 727-38.
5. Kwon CS, Daniele P, Forsythe A, Ngai C. A systematic literature review of the epidemiology, health-related quality of life impact, and economic burden of immunoglobulin A nephropathy. J Health Econ Outcomes Res 2021; 8: 36-45.