AkesoBio Announces Phase 3 AirFLO Trial of Aikosivir™ (Ziresovir) Meets Primary Endpoint in Hospitalized Infants and Young Children with RSV Infection

● In Phase III clinical trialsAirFLOIn the trial, Eskay™ significantly reduced symptom scores compared with placebo (p=0.002) and viral load (p=0.006), achieving the primary and key secondary endpoints of the trial

● RSVInfection is the leading cause of hospitalization and death among children under five years of age due to viral infections.

● Aisiwei™ is the world’s first RSV antiviral drug to successfully complete pivotal Phase III clinical trials in the pediatric patient population.

● ArkBio™ plans to submit a New Drug Application (NDA) to Chinese regulatory authorities in mid-2022

ArkBio (Shanghai Aike 100 Biomedical Technology Co., Ltd.), a biopharmaceutical company dedicated to drug development in the fields of pediatrics and respiratory diseases, announced that its drug for treating respiratory syncytial virus (RSV) infection, Aisiwei™ (generic name: ziresovir), achieved positive results in a multicenter Phase III clinical trial, meeting both the primary and key secondary endpoints. In this clinical trial, named AirFLO, Aisiwei™ significantly reduced symptom scores (p=0.002) and viral load (p=0.006) compared with placebo in hospitalized infants and young children with RSV infection. This study represents the first Phase III clinical trial globally to report positive results for an oral RSV antiviral drug.

Professor Ni Xin, President of Beijing Children’s Hospital affiliated with Capital Medical University, Director of the National Center for Children’s Health, and Principal Investigator of the AirFLO trial, stated: “According to WHO statistics, approximately 64 million children worldwide are infected with respiratory syncytial virus (RSV) annually, among whom 160,000 die from RSV-related diseases, making it a significant cause of childhood mortality. There is an urgent need for safe, effective, and conveniently administered therapeutic agents. The positive results from the AirFLO study suggest that the landscape of pharmacological treatment for RSV infection may be transformed, holding substantial significance for the advancement of pediatric clinical diagnosis and management of RSV infection. If qirisovir successfully reaches the market, it is expected to break the current predicament of lacking available treatments for this disease and fill a major gap in the antiviral field both domestically and internationally.”

In the Phase 3 AirFLO clinical trial, Esketamine™ demonstrated rapid onset of action, with a 30% greater improvement in symptom scores within 48 hours of treatment compared to the placebo group (p=0.002). In patients under six months of age, Esketamine™ showed more significant clinical benefits, with a 55% greater improvement in symptom scores compared to placebo (p<0.001). Esketamine™ also exhibited significant antiviral efficacy; the treatment group experienced a substantial reduction in viral load during therapy compared to placebo, with a further 77% reduction in viral load on day 5 relative to the control group (p=0.006). Esketamine™ has demonstrated a favorable safety profile in multiple clinical studies conducted to date. ArkBio plans to submit a New Drug Application (NDA) for Esketamine™ to the National Medical Products Administration (NMPA) in mid-2022.

Dr. Wu Zheng, Chairman and Chief Executive Officer of ArkBio, stated, “We are highly pleased with the results of the AirFLO study. We extend our gratitude to all enrolled patients and their families, as well as to our outstanding team of investigators. The success of this clinical trial would not have been possible without the selfless dedication and hard work of every participant. Eskavir™ demonstrated favorable efficacy and safety in the VICTOR Phase II international multicenter clinical trial, and we are delighted to see that the results from the Phase III AirFLO study further substantiate its safety and efficacy data. Eskavir™ is the first innovative pediatric drug invented and developed in China and subsequently expanded to the global market. Remaining true to our mission, we will continue our efforts to develop more innovative medicines with significant clinical value for patients in China and around the world.”

RSV is a common airborne RNA respiratory virus that enters the trachea and lungs via inhalation through the mouth and nose, invades epithelial cells causing airway damage, and secretes respiratory mucus that obstructs the lumen, leading to breathing difficulties. Common symptoms of RSV infection include runny nose, fever, cough, and wheezing; severe cases can progress to respiratory distress, potentially causing airway obstruction, respiratory failure, and even death.

RSV infection is the leading cause of hospitalization and death due to viral infections among children under five years of age worldwide. According to WHO statistics, approximately 35 million children under five were infected with RSV globally in 2020, including 3 million pediatric patients in China. Up to 150,000 people die from RSV infection annually worldwide. Among pediatric patients, even mild cases of untreated RSV infection may progress to chronic respiratory diseases, such as wheezing and asthma, thereby adversely affecting children’s healthy growth and development.

Populations susceptible to RSV include children, the elderly, and adults with compromised immune systems; over 90% of children are infected with RSV before the age of two. Currently, there are no specific antiviral drugs targeting RSV.

Esway™ is a novel small-molecule inhibitor targeting the RSV fusion protein. It prevents viral entry into human cells by binding to the viral F protein. Additionally, it blocks cell-to-cell fusion, thereby inhibiting the formation of syncytia—a hallmark of RSV-infected cells—and exerting its antiviral effect.

Aisiwei™ is the first RSV antiviral drug to successfully complete pivotal Phase III clinical trials globally, and also the first innovative pediatric drug invented and developed in China before expanding worldwide. Meanwhile, Qiruisuowe is the first non-oncology innovative drug to receive “Breakthrough Therapy” designation from the National Medical Products Administration (NMPA).

The AirFLO study (NCT04231968) is a randomized, double-blind, placebo-controlled, multicenter pivotal Phase III clinical trial designed to evaluate the efficacy, safety, tolerability, pharmacokinetics, and antiviral activity of Eskewei™ in hospitalized infants and young children with respiratory syncytial virus (RSV) infection. The trial enrolled 311 subjects from more than 30 pediatric clinical research centers across China, who received either Eskewei™ or placebo for five consecutive days. The primary endpoint of this study was the change from baseline in the bronchiolitis symptom score; the key secondary endpoint was the reduction in viral load from baseline.

ArkBio is an innovative biopharmaceutical company dedicated to addressing significant unmet clinical needs in the fields of pediatric and respiratory diseases. Since its establishment in 2013, the company has accumulated multiple core technologies and global patents in the research and development of innovative drugs with novel mechanisms of action. By adopting a R&D model that combines independent innovation with external licensing, ArkBio has developed a highly differentiated and robust product pipeline. Its flagship product, Aiswei™, is a globally leading anti-RSV therapeutic and the first non-oncology new drug included in China’s National Breakthrough Therapy Designation program. Another product nearing commercialization is AZSTARYS, a new ADHD medication recently approved by the U.S. FDA, for which ArkBio holds the development and marketing rights in Greater China. The company also has several other new drug candidates with best-in-class or first-in-class potential currently in clinical trials or preclinical development.

ArkBio has established strategic partnerships with multinational pharmaceutical companies such as Roche/Genentech, leading U.S. academic institutions including the Scripps Research Institute, the Institute of Microbiology of the Chinese Academy of Sciences, domestic and international biotechnology firms, and global healthcare investment institutions.