Japan Approval Announcement
Eisai recently announced that the Ministry of Health, Labour and Welfare (MHLW) of Japan has approved Tazverik (tazemetostat), an oral, first-in-class EZH2 inhibitor, for the treatment of patients with relapsed or refractory EZH2 mutation‑positive follicular lymphoma (FL), limited to cases where standard therapies are not applicable.
Basis for Approval: Clinical Study Results
The approval was based on data from a multicenter, open‑label, single‑arm Phase II clinical trial (Study 206) conducted by Eisai in Japan, as well as other clinical studies conducted by Epizyme outside Japan.
Study Design
Study 206 enrolled patients with relapsed or refractory EZH2 mutation‑positive primary follicular lymphoma (FL).
Primary endpoint: Objective Response Rate (ORR)
Secondary endpoint: Safety
Key Efficacy Results
The study met its primary endpoint and demonstrated a statistically significant tumor response exceeding the predefined threshold.By Independent Review Committee (IRC) assessment:
ORR in EZH2 mutation‑positive relapsed or refractory FL patients (n=17): 76.5% (90% CI: 53.9–91.5)
Common Treatment‑Emergent Adverse Events (TEAE ≥ 25%)
Dysosmia (52.9%)
Nasopharyngitis (35.3%)
Lymphopenia (29.4%)
Blood creatine phosphokinase increased (29.4%)
Post‑Marketing Surveillance
Eisai will conduct a post‑marketing all‑case surveillance for all patients treated with Tazverik until the predefined patient enrollment number is reached under the approval conditions specified by the MHLW.
Global Approvals of Tazemetostat (Tazverik)
US FDA Approval (January 2020)
Accelerated approval for adults and pediatric patients aged 16 years and older with metastatic or locally advanced epithelioid sarcoma (ES) who are not candidates for complete resection.
Efficacy: ORR = 15% in the ES cohort; 67% of responders had Duration of Response (DOR) ≥ 6 months.
Tazemetostat became the first FDA‑approved EZH2 inhibitor and the first therapy specifically approved for ES, representing a milestone in the clinical treatment of ES.
US FDA Approval (June 2020)
Accelerated approval for two indications of relapsed or refractory (R/R) follicular lymphoma:
Adult patients with EZH2 mutation‑positive R/R FL confirmed by an FDA‑approved test, who have received at least two prior systemic therapies.
Adult patients with R/R FL for whom no satisfactory alternative treatment options exist.
This approval was based on ORR and DOR data from a Phase II clinical trial in FL patients with either mutant or wild‑type EZH2.
