#Japan #Tokyo #Eisai #Henlius #Serplulimab

Eisai and Henlius Forge Exclusive Partnership for Serplulimab in Japan

In a notable development within the pharmaceutical industry, Eisai Co., Ltd., headquartered in Tokyo, has entered into a collaboration with Shanghai Henlius Biotech, Inc. This exclusive agreement paves the way for the commercialization of Serplulimab, an innovative anti-PD-1 monoclonal antibody, in the Japanese market. The announcement was made on February 5, 2026, highlighting the crucial steps both companies are undertaking to address high unmet medical needs in oncology.

Serplulimab, known as HANSIZHUANG in China and Hetronifly® in the European Union, is distinguished by its unique binding mechanism, setting it apart from other anti-PD-1 antibodies. This novel immunotherapeutic agent has shown promise in treating various cancer types, including squamous cell lung cancer and small cell lung cancer. In China, it has already secured approval for a variety of cancer indications such as squamous non-small cell lung cancer (sqNSCLC) and extensive-stage small cell lung cancer (ES-SCLC).

Currently, Henlius is conducting a Phase II bridging clinical trial for the indication of ES-SCLC in Japan but already has plans to submit applications based on positive trial results in the fiscal year 2026. Notably, the Phase III clinical trial data that supports the drug's approval in other regions will also play a critical role in this process. The demand for effective treatments in Japan is underscored by the estimated 13,000 patients afflicted with ES-SCLC—as well as approximately 28,000 with non-high-frequency microsatellite instability (non-MSI-High) metastatic colorectal cancer.

Under the terms of this partnership, Eisai will acquire exclusive rights to market Serplulimab in Japan. Beyond the current indications, Henlius also eyes expansion into clinical trials for perioperative gastric cancer in the region, illustrating the commitment to tackling unmet needs in cancer treatment. Eisai has committed an upfront payment of $75 million to Henlius, alongside additional milestone payments totaling up to $80.01 million and possible sales milestones reaching $233.3 million. This financial commitment emphasizes the potential both companies see in Serplulimab.

The collaborative efforts position both Eisai and Henlius to leverage their respective strengths—Eisai with its extensive experience and knowledge of the Japanese market, and Henlius with its innovative capabilities in cancer therapies. Dr. Jason Zhu, CEO of Henlius, expressed excitement about this partnership, recognizing Japan as a pivotal market for advancing Serplulimab and establishing actionable strategies to meet patient needs in oncology.

Conversely, Toshihiko Yusa, Executive Officer at Eisai, highlighted the urgency driven by the significant unmet medical needs for patients suffering from various cancers in Japan. The drug targets crucial areas in oncology where timely access to breakthrough treatments can greatly improve patient outcomes.

This partnership represents a significant milestone not only for both companies but also for thousands of patients in Japan who are eagerly awaiting new treatment options. With a shared vision focused on addressing crucial healthcare needs, Eisai and Henlius are poised to make impactful contributions to cancer care.

In summary, the entry of Serplulimab into the Japanese market, following this strategic partnership, signifies a proactive approach to meet the pressing demands in oncology treatment landscapes, marking a hopeful turn for patients and healthcare providers alike as they navigate the challenges of cancer care in Japan. The collaboration fortifies both companies’ commitment to innovation in biopharmaceuticals, embodying their mission to transform scientific advancements into meaningful patient benefits on a global scale.