The FDA has approved tazemetostat for the treatment of 2 different follicular lymphoma (FL) indications, both of which were granted accelerated approval with a priority review based on phase 2 clinical trial cohorts.1

FL is a slow-growing or indolent form of non-Hodgkin lymphoma (NHL), which accounts for between 20% and 30% of all NHL cases. It is not a curable disease, and symptoms can include enlargement of lymph nodes in the neck, underarms, abdomen, or groin, as well as fatigue, shortness of breath, night sweats, and weight loss.2

Tazemetostat was approved for 2 indications:1
  • Adult patients with relapsed or refractory FL whose tumors are positive for an EZH2 mutation and who have received 2 or more prior systemic therapies.
  • Adults with relapsed or refractory FL who have no satisfactory alternative treatment options.

“In our view, there remains no clear standard of care in the relapsed and/or refractory FL population as not all patients benefit from today’s available therapies,” said Shefali Agarwal, MD, chief medical officer of Epizyme, in a press release. “Based on this label, physicians will have the ability to use their clinical discretion to prescribe Tazverik for their relapsed or refractory patients regardless of EZH2 mutational status and without regard to a specific line of treatment where other options are not satisfactory.”1

The efficacy of the drug was established in an open-label, single-arm, multi-center phase 2 clinical trial of patients with histologically confirmed FL whose disease had progressed after at least 2 prior systemic treatment regimens.1 One cohort enrolled 45 patients with EZH2 activating mutations, and a second cohort enrolled 54 patients with wild-type EZH2. All patients were treated with 800 mg of tazemetostat, administered orally twice per day.1

Among the 45 patients with an EZH2 activating mutation, 42 had been treated with at least 2 prior systemic therapies. This group had an overall response rate (ORR) of 69%, with 12% achieving a complete response and 57% achieving a partial response. The median duration of response was 10.9 months and ongoing.1

There were 54 patients with wild-type EZH2, 53 of whom had been previously treated with 2 or more systemic therapies. Among this group, the ORR was 34%, with 4% of patients achieving a complete response and 30% achieving a partial response. The median duration of response was 13 months.1

Serious adverse events (AEs), irrespective of attribution, occurred in 30% of the total patients. Serious AEs in 2% or more of patients who received tazemetostat included general physical health deterioration, abdominal pain, pneumonia, sepsis, and anemia. The most common AEs were seen in 20% or more of patients, and included fatigue, upper respiratory tract infection, musculoskeletal pain, nausea, and abdominal pain.1

Eight patients discontinued treatment due to AEs. There were no reported deaths in the study and no black box warnings or contraindications.1

“Follicular lymphoma remains an incurable disease, and even with the availability of new drugs in recent years, there have remained important unmet needs in the treatment of follicular lymphoma,” said John Leonard, MD, an investigator in the Phase 1b/3 confirmatory trial for tazemetostat, in a press release. “The durable responses observed with this drug are notable in the context of the safety profile and route of oral, at-home administration, and will offer an important new option for physicians as we care for patients with relapsed/refractory follicular lymphoma.”1

REFERENCES
  1. Epizyme Announces US FDA Accelerated Approval of Tazverik (tazemetostat) for Relapsed/Refractory Follicular Lymphoma [news release]. Epizyme; June 18, 2020. https://epizyme.gcs-web.com/news-releases/news-release-details/epizyme-announces-us-fda-accelerated-approval-tazveriktm-0. Accessed June 18, 2020.
  2. About Lymphoma, Lymphoma Research Foundation. https://lymphoma.org/aboutlymphoma/nhl/fl/. Accessed June 18, 2020.