A Study to Assess the Efficacy, Safety, Pharmacodynamics, and Pharmacokinetics of Tazemetostat in Combination With Lenalidomide Plus Rituximab Versus Placebo in Combination With Lenalidomide Plus Rituximab in Adult Patients at Least 18 Years of Age With Relapsed/Refractory Follicular Lymphoma. (SYMPHONY-1)

The participants of this study would have relapsed/refractory follicular lymphoma. Follicular lymphoma is a type of blood cancer. It is referred to as 'relapsed' when the disease has come back after a period of improvement after that follows a treatment regimen and 'refractory' when treatment no longer works. Stage 1 of this trial studied the safety and the level that adverse effects of each of the study drug combinations can be tolerated (known as tolerability). It is also designed to establish a recommended study drug dosage for stage 2 and 3. Stage 1 of the study is completed. Stages 2 and 3 were designed to evaluate and compare how long participants live without their disease getting worse when receiving the study drug in combination with other drug treatment versus the placebo (dummy drug) in combination with other drug treatment. However, following an urgent safety measure, treatment with tazemetostat and placebo was discontinued, enrollment was stopped, and the study was unblinded. As a result, post-urgent safety measure analyses are descriptive in nature.

• Phase 1b: Recommended Phase 3 Dose (RP3D) of tazemetostat in combination with rituximab and lenalidomide (R2)
• Phase 3: Progression-Free Survival (PFS) in the Intent-to-treat wild-type (ITT-WT) populations
• Phase 3: PFS in the Intent-to-treat mutant-type (ITT-MT) population
• Phase 3: PFS in the R/R FL population regardless of mutation status by Investigator assessment

1. Study completion expected

   Mar 1, 2029

2. Primary completion expected

   Feb 13, 2027

3. Last registry update

   Oct 5, 2026

4. Started

   Jun 11, 2020

5. Registered

   Jan 13, 2020