HUTCHMED (China) Limited announces that it has completed patient enrollment of a bridging study of tazemetostat in China. The bridging study is a multicenter, open-label, Phase II study to evaluate the efficacy, safety and pharmacokinetics of tazemetostat for the treatment of patients with relapsed/refractory follicular lymphoma (?R/R FL?). The primary objective is to evaluate the objective response rate (?ORR?) of tazemetostat for the treatment of patients with R/R FL whose disease harbor EZH2 mutations (Cohort 1).

The secondary objectives included duration of response (?DoR?), progression-free survival (PFS), and overall survival (OS) of tazemetostat for the treatment of R/R FL patients whose disease do or do not harbor EZH2 mutations (Cohort 2), as well as to evaluate the safety and pharmacokinetics. The lead principal investigator is Dr. Junning Cao of Shanghai Fudan University Cancer Center. A total of 42 patients were enrolled.

Tazemetostat is a first-in-class methyltransferase inhibitor of EZH2 developed by Epizyme Inc. (?Epizyme?), an Ipsen company. It is approved by the U.S. Food and Drug Administration (?FDA?) for the treatment of certain patients with advanced epithelioid sarcoma (?ES?) and certain patients with R/R FL under the FDA accelerated approval granted in January and June 2020, respectively. HUTCHMED entered into a strategic collaboration to research, develop, manufacture and commercialize tazemetostat in China, Hong Kong, Macau and Taiwan.

In May 2022, tazemetostat was approved by the Health Commission and Medical Products Administration of Hainan Province of China to be used in the Hainan Boao Lecheng International Medical Tourism Pilot Zone (?Hainan Pilot Zone?), under the Clinically Urgently Needed Imported Drugs scheme, for the treatment of certain patients with ES and FL consistent with the label as approved by the FDA. In March 2023, tazemetostat was approved and launched in Macau. A market authorization application has been under review in Hong Kong since December 2022.

Tazemetostat was included in the Chinese Society of Clinical Oncology (CSCO) guidelines for ES in 2022 and for FL in 2023. FL is a subtype of non-Hodgkin?s lymphoma (?NHL?). FL accounts for approximately 17% of NHL.

In 2020, there were an estimated 16,000 and 13,000 new cases of FL in China and the U.S., respectively. ES is a rare, slow-growing type of soft tissue cancer. Radical tumor resection is the primary treatment for patients with ES.

However, ES is known for its high propensity for locoregional recurrence and distant metastases. The survival of patients with ES is often unsatisfactory with very limited treatment options. TAZVERIK® is a methyltransferase inhibitor indicated in the United States for the treatment of: Adults and pediatric patients aged 16 years and older with metastatic or locally advanced ES not eligible for complete resection.

Adult patients with R/R FL whose tumors are positive for an EZH2 mutation as detected by an FDA-approved test and who have received at least two prior systemic therapies. Adult patients with R/R FL who have no satisfactory alternative treatment options. These indications are approved under accelerated approval by the U.S. FDA based on ORR and DoR.

Continued approval for these indications may be contingent upon verification and description of clinical benefit in confirmatory trials. The most common (=20%) adverse reactions in patients with ES are pain, fatigue, nausea, decreased appetite, vomiting and constipation. The most common (=20%) adverse reactions in patients with FL are fatigue, upper respiratory tract infection, musculoskeletal pain, nausea and abdominal pain.

TAZVERIK® is approved in Japan with the indication of relapsed or refractory EZH2 gene mutation-positive FL (only when standard treatment is not applicable). TAZVERIK® is a registered trademark of Epizyme Inc. HUTCHMED and Ipsen are developing tazemetostat in various hematological and solid tumors in Greater China. SYMPHONY-1 (EZH-302) is an international, multicenter, randomized, double-blind, active-controlled, 3-stage, biomarker-enriched, confirmatory Phase 1b/3 study, which is designed to evaluate the safety and efficacy of tazemetostat in combination with rituximab + lenalidomide (R2) in patients with R/R FL after at least one prior line of therapy (clinicaltrials.gov identifier: NCT04224493).

China combination study in R/R FL is an open-label, Phase ?? study in approximately 140 patients to evaluate the safety, tolerability and preliminary anti-tumor efficacy of tazemetostat in combination with amdizalisib in patients with R/R lymphoma.