The patent war over core products has escalated again, casting uncertainty over Hunan Mabgeek Biotech's planned Hong Kong IPO.

Sunshine Guojian Pharmaceutical (Shanghai) Co., Ltd. and Mabgeek Biotech's patent dispute has taken a new turn. On November 3, an investor inquired on an interactive platform about Sunshine Guojian's recent move to invalidate Mabgeek's IL-4R antibody patent (CN202010309238.8). The investor noted that in 2020, another IL-4R patent held by Mabgeek was ruled by the Shanghai Intellectual Property Court to have infringed Sunshine Guojian's rights. The investor asked whether the current patent under challenge is new, related to MG-K10, the grounds for invalidation, and potential impact on MG-K10's market approval.

Sunshine Guojian responded that the contested patent (CN202010309238.8) was filed by Mabgeek in 2020 and involves MG-K10. The company has submitted application materials to China's National Intellectual Property Administration but declined further comment due to legal and commercial considerations. Sunshine Guojian emphasized its commitment to protecting intellectual property and trade secrets, stating it will take legal measures against suspected infringements.

The company also referenced its 2020 court victory regarding Mabgeek's other IL-4R patent (CN201710074949.X).

**Core Product Caught in Patent Crossfire** Founded in 2016, Mabgeek focuses on innovative therapies for allergic and autoimmune diseases like atopic dermatitis, asthma, and prurigo nodularis. In August 2025, the company filed for a Hong Kong IPO with China International Capital Corporation as sole sponsor, seeking to alleviate financial pressure.

Mabgeek's pipeline includes eight candidates, with lead asset MG-K10—a long-acting anti-IL-4Rα monoclonal antibody—being the most advanced, currently in Phase III trials. Other key products like MG-014 and MG-013 are at various development stages.

The patent battle began in 2018 when Sunshine Guojian sued Mabgeek for patent infringement, claiming the technology was developed as work-for-hire and belonged to the company. While a 2020 court ruling awarded patent application rights to Sunshine Guojian, it didn't specifically address MG-K10's patent rights.

Now, as Mabgeek approaches its listing, both regulators and Sunshine Guojian (former employer of Mabgeek's founders) have renewed focus on the patent dispute, with Sunshine Guojian directly targeting MG-K10.

**Founding Team's Origins Fuel Dispute** Mabgeek's founders and several executives previously worked at Sunshine Guojian, which sparked the conflict. A legally binding judgment determined that a patent (ZL201710074949.X) filed by Mabgeek in February 2017—within one year of founders Zhang Chenghai and Zhu Lingqiao's departure from Sunshine Guojian—was closely related to their former roles. The court awarded patent application rights to Sunshine Guojian, finding significant overlap between Mabgeek's technical solutions and Sunshine Guojian's earlier IL-4R antibody project.

Mabgeek's valuation and IPO prospects heavily depend on MG-K10, which features a once-every-four-weeks dosing regimen for treating moderate-to-severe atopic dermatitis, asthma, and prurigo nodularis. The drug is undergoing Phase III trials in mainland China, Hong Kong, and Singapore. In July 2025, Mabgeek raised approximately 260 million yuan in its latest funding round, achieving a post-money valuation of 2.64 billion yuan.

**Mounting Challenges** The patent battle could be a critical blow to Mabgeek. While the company claims to have adjusted its patent strategy to avoid infringement and maintain development timelines, Sunshine Guojian's invalidation petition adds uncertainty to MG-K10's commercialization prospects in the increasingly competitive IL-4Rα space.

As a pre-revenue biotech, Mabgeek has sustained consistent losses. Financial disclosures show revenues of 8.722 million yuan in 2023, 24,000 yuan in 2024, and zero in Q1 2025, with net losses totaling approximately 458 million yuan over the same period. R&D expenses reached 166 million yuan, 150 million yuan, and 24 million yuan respectively.

The company's debt-to-asset ratio has consistently exceeded 100%, peaking near 700% at end-2023 before improving to 166.83% by March 2025 post-funding. Mabgeek's prospectus acknowledges that its financial viability hinges on successfully developing, obtaining approvals for, and commercializing its pipeline—especially MG-K10, MG-014, and MG-013.

Chinese regulators have asked Mabgeek to clarify whether the patent dispute with Sunshine Guojian materially impacts operations or creates listing obstacles. Major shareholders include Chairman Zhang Chenghai (controlling 42.65% voting rights), CMS Pharma, Zhangjiang Group, and Hunan Xiangjiang.

**Intensifying Market Competition** Investors are watching whether patent litigation could exclude Mabgeek from the IL-4Rα market. Global IL-4Rα-targeted therapies reached approximately $131.7 billion in 2022, with China's market projected to hit $4.08 billion by 2030, according to Frost & Sullivan.

Domestic IL-4Rα monoclonal antibodies are accelerating toward market, with competition expected between 2026-2027. Internationally, Sanofi and Regeneron's Dupixent generated €13.072 billion in 2024 sales. In China, Keymed Biosciences' spesolimab became the first domestic IL-4Rα mAb approved in September 2024 for three indications, establishing an early lead.

Over ten Chinese firms—including Sunshine Guojian, Connect Biopharma (CBP-201's BLA accepted), Genrix Biopharma, Qyuns Therapeutics, Akeso Biopharma, Hengrui Pharma, and Chia Tai Tianqing—have entered the space, with most candidates in late-stage clinical development. Against this backdrop, Mabgeek's MG-K10 faces steep challenges.