RecruitingDrug trialA Phase 1/2, Open-label Study of Valemetostat in Combination With Rituximab and Lenalidomide in Relapsed or Refractory Follicular LymphomaTo find a recommended dose of valemetostat that can be given in combination with rituximab and lenalidomide to patients with follicular lymphoma. The safety and effects of this drug combination will also be studied