China's National Medical Products Administration (NMPA) has granted conditional approval to tazemetostat (Tazverik) for the treatment of adult patients with relapsed or refractory EZH2-mutated follicular lymphoma who have received at least two prior systemic therapies. This marks the first nationwide regulatory approval for tazemetostat in China and establishes it as the first and only EZH2 inhibitor approved by the NMPA.
The approval represents HUTCHMED's fourth product approval in China and its first in hematological malignancies, expanding the company's therapeutic footprint beyond solid tumors. Tazemetostat was previously approved by the US Food and Drug Administration (FDA) in 2020 and by Japan's Ministry of Health, Labour and Welfare for certain patients with relapsed/refractory follicular lymphoma.
Clinical Evidence Supporting Approval
The NMPA's decision was supported by findings from a multicenter, open-label, Phase II bridging study (NCT05467943) conducted in China, alongside data from clinical trials conducted outside China. The bridging study enrolled 42 patients aged 18 years or older with histologically confirmed relapsed/refractory follicular lymphoma with at least one measurable lesion.
Patients in the trial received tazemetostat at 800 mg twice daily, administered in continuous 28-day cycles. The primary endpoint was overall response rate (ORR) among patients with relapsed/refractory EZH2-mutated follicular lymphoma, with secondary endpoints including overall survival, safety, and pharmacokinetics.
"This approval represents a significant advancement in the management of this challenging disease," said Dr. Junning Cao of Fudan University Shanghai Cancer Center, the lead principal investigator of the bridging study. "The majority of patients with follicular lymphoma experience multiple relapses over their lifetime, posing substantial treatment difficulties and often leading to poor outcomes. Tazemetostat has demonstrated promising efficacy in patients harboring EZH2 mutations in clinical trials."
Mechanism of Action and Disease Context
Tazemetostat is a first-in-class methyltransferase inhibitor of EZH2 developed by Epizyme, now an Ipsen company. As an epigenetic therapy, it represents a novel approach to treating follicular lymphoma, the second most common subtype of non-Hodgkin's lymphoma, accounting for 20-30% of all NHL cases. In 2022, there were an estimated 81,000 new cases of NHL in China.
The drug specifically targets patients whose tumors harbor EZH2 mutations, representing a precision medicine approach to this hematological malignancy. This targeted therapy addresses a specific patient population with limited treatment options after multiple lines of therapy.
Partnership and Commercialization
In 2021, HUTCHMED and Epizyme entered a strategic partnership wherein HUTCHMED assumed responsibility for the research, development, manufacturing, and commercialization of tazemetostat in China Mainland, Hong Kong, Macau, and Taiwan. Epizyme remains the Marketing Authorization Holder of tazemetostat in China.
"We are thrilled to be able to bring this innovative EZH2 inhibitor to patients in China," said Dr. Michael Shi, Head of R&D and Chief Medical Officer of HUTCHMED. "This approval highlights our dedication to addressing unmet medical needs not only through our internal pipeline but also through partnering. As we move forward, we are dedicated to making this product available to relapsed/refractory follicular lymphoma patients as soon as possible."
Confirmatory Trial and Future Directions
The ongoing SYMPHONY-1 study (NCT04224493) will serve as the confirmatory trial to validate the clinical benefits of tazemetostat. This international, multicenter, randomized, double-blind, active-controlled, three-stage, biomarker-enriched, confirmatory Phase 1b/3 study is designed to evaluate the safety and efficacy of tazemetostat in combination with rituximab and lenalidomide in patients with relapsed/refractory follicular lymphoma after at least one prior line of therapy.
The primary endpoints of SYMPHONY-1 include identification of the recommended Phase 2 dose of tazemetostat plus lenalidomide and rituximab, as well as progression-free survival in the EZH2-mutant and wild-type populations. Secondary endpoints encompass pharmacokinetics, complete response rate, overall response rate, overall survival, duration of response, duration of complete response, disease control rate, safety, and quality of life.
Clinical Implications
The approval of tazemetostat provides a new treatment option for Chinese patients with relapsed or refractory follicular lymphoma who have limited therapeutic alternatives after multiple treatment failures. The conditional approval pathway allows earlier access to this innovative therapy while additional confirmatory data are being collected.
For patients with EZH2 mutations who have exhausted standard treatment options, tazemetostat represents a targeted approach that addresses the specific molecular driver of their disease. This approval aligns with the global trend toward precision medicine in oncology, where treatments are increasingly tailored to specific genetic alterations.
Safety Profile
In clinical trials, the most common adverse reactions (≥20%) in patients with follicular lymphoma treated with tazemetostat included fatigue, upper respiratory tract infection, musculoskeletal pain, nausea, and abdominal pain. The safety profile observed in Chinese patients was consistent with that seen in global studies.
The conditional approval by the NMPA reflects the agency's commitment to expediting access to innovative therapies for serious conditions with significant unmet medical needs, while ensuring that confirmatory studies are conducted to verify and describe the anticipated clinical benefit.
