Study of Brentuximab Vedotin Combined With RCHOP or RCHP in Front-line Treatment of Patients With Diffuse Large B-cell Lymphoma (DLBCL)

This study has 3 parts. The purpose of Part 1 of this study is to assess the safety and efficacy of brentuximab vedotin in combination with RCHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone) (known as BV+RCHOP) in patients with DLBCL who have never been treated. Patients will be randomly assigned in a 1:1 ratio to receive RCHOP together with 1 of 2 doses of brentuximab vedotin. Patients will be tested to see if there is a difference in side effects between the 2 groups. The purpose of Part 2 of this study is to assess the safety and efficacy of brentuximab vedotin in combination with RCHP (rituximab, cyclophosphamide, doxorubicin, and prednisone) (known as BV+RCHP) in patients with CD30-positive DLBCL who have never been treated. Patients will be enrolled to receive RCHP together with 1.8mg/kg of brentuximab vedotin. The purpose of Part 3 of this study is to assess the safety and efficacy of BV+RCHP compared to standard RCHOP in patients with CD30-positive DLBCL that have never been treated. Patients will be randomly assigned in a 1:1 ratio to receive either BV+RCHP or RCHOP. Patients will be tested to see if there is a difference in side effects between the 2 groups.