Hengrui Medicine has achieved a significant regulatory milestone with China's National Medical Products Administration (NMPA) granting conditional approval for Zemetostat, marking the country's first enhancer of zeste homolog 2 (EZH2) inhibitor for treating hematological malignancies. The Liangyungang-based pharmaceutical company announced that Zemetostat is indicated for adult patients with relapsed or refractory peripheral T-cell lymphoma, addressing a critical unmet medical need in China's oncology landscape.
Clinical Efficacy and Mechanism of Action
Zemetostat's approval was supported by robust clinical trial data, including a Phase II bridging study (NCT05467943) that demonstrated an objective response rate of 34% in patients with relapsed or refractory follicular lymphoma with EZH2 mutations. The drug operates through a dual mechanism of action, inhibiting both wild-type and gain-of-function mutant EZH2 while also targeting EZH1 to prevent compensatory pathways.
The therapeutic's unique approach extends beyond direct tumor targeting. Zemetostat modulates the tumor microenvironment by reprogramming tumor cells to re-express T cell engagement genes and reduce regulatory T cell populations, potentially enhancing the efficacy of immunotherapies including CAR-T cell therapies. This dual targeting of intrinsic tumor dependencies and immune evasion mechanisms positions the drug as a versatile platform for combination strategies.
Market Position and Competitive Landscape
Zemetostat joins a limited global field of approved EZH2 inhibitors. Only two other EZH2 inhibitors have received regulatory approval worldwide: Tazverik, developed by Massachusetts-based Epizyme and approved by the US FDA in January 2020, and Ezharmia, an EZH1/2 inhibitor developed by Tokyo-based Daiichi Sankyo and approved in Japan in September 2022.
The global EZH2 inhibitors market is projected to experience substantial growth, with a compound annual growth rate of 13.88% from 2025 to 2034, reaching $9.59 billion by 2034. The hematological segment specifically is forecasted to expand from $0.27 billion in 2023 to $0.85 billion by 2032, driven by rising adoption of targeted therapies in hematological malignancies.
Development Investment and Pipeline
Hengrui has invested approximately CNY213 million (USD29.9 million) in Zemetostat's research and development projects. The company is further strengthening its position in epigenetic therapies through ongoing Phase III trials, including SYMPHONY-1, which evaluates Zemetostat's efficacy in combination with rituximab and lenalidomide for extending progression-free survival.
The company's pipeline includes next-generation EZH2 inhibitors such as SHR2554, currently in Phase II trials for follicular lymphoma, demonstrating Hengrui's commitment to addressing resistance mechanisms and expanding into new indications including solid tumors with SWI/SNF complex dysfunction.
Strategic Business Impact
The approval represents a pivotal moment in Hengrui's transformation from a generic drug-focused company to an innovative pharmaceutical developer. In the six months ended June 30, revenue from innovative drug sales and licensing agreements reached CNY9.6 billion (USD1.3 billion), accounting for 61% of total income, with sales topping CNY7.6 billion.
Following the announcement, Hengrui shares climbed 0.6% to CNY68.76 (USD9.64) in Shanghai trading, after earlier jumping by as much as 3.5%, reflecting investor confidence in the company's innovative drug portfolio and market positioning in China's growing oncology sector.
