Lenalidomide and Gemcitabine in Relapsed or Refractory Peripheral T-cell Lymphomas

There are 3000 newly diagnosed lymphoma patients in Taiwan, and T-cell neoplasms accounted for 17.4% of total lymphomas. Peripheral T-cell lymphomas (PTCL) are heterogeneous malignancies, and peripheral T-cell lymphoma not otherwise specified (PTCL-NOS), angioimmunoblastic T-cell lymphoma (AITL), and anaplastic large cell lymphoma (ALCL) are the most common subtypes. Patients with relapsed or refractory PTCL to 1st-line chemotherapy had dismal prognosis under conventional chemotherapy. Combination of gemcitabine with platinum chemotherapy may be effective regimens, because they provided objective response rate (ORR) of 70% in PTCL patients. Since most salvage chemotherapy regimens provided limited activity in PTCL, many new regimens were studied in PTCL. Except brentuximab vedotin provided high activity through targeting CD30 on ALCL, new regimens (including lenalidomide) provided ORR about 20% and PFS about 3 months in PTCL. Lenalidomide is an immunomodulatory agent, and it reduces T-regulatory cells, activates CD8-positive T cells, and increases natural killer cell numbers and in activation status. Gemcitabine may augment immune responses in several ways: activating T cells, increasing the amount of dendritic cells, increasing the amounts of antigens loaded onto antigen-presenting cells, and down-regulating T-regulatory cells. We design this phase 2 study under the hypothesis of synergistic effect of anti-tumor immunity and efficacy to PTCL in combination with lenalidomide and gemcitabine. The dose of lenalidomide monotherapy to treat PTCL is 25 mg daily based on previous studies, and we also start this dose in our study initially. Lenalidomide in combination with gemcitabine in 1st-line treatment of patients with advanced pancreatic cancer were studied before. Patients could tolerate oral lenalidomide of 25 mg daily on days 1 to 21, and intravenous gemcitabine dose of 1000 mg/m2 on days 1, 8, and 15, of each 28-day cycle. Because our enrolled patients will receive previous-line chemotherapy and combination of lenalidomide and gemcitabine may exacerbate myelosuppression, we designed oral lenalidomide of 25 mg daily on days 1 to 14, and intravenous gemcitabine dose of 1000 mg/m2 on days 1 and 8, of each 21-day cycle. In order to monitor toxicities and adjust drug doses closely, we arrange phase Ib study to evaluate dose-limiting toxicities about combination of lenalidomide and gemcitabine. The schedules about dose delays and modifications were also designed in phase Ib and II studies.