Background: Brentuximab vedotin (BV, ADCETRIS) is approved for the treatment of adults with treatment-naïve Stage III or IV cHL in combination with AVD (Connors 2017). Nivolumab is approved for treatment of adults with relapsed/refractory cHL. Both agents have been well tolerated with promising activity when combined with multi-agent chemotherapy. The combination of BV plus nivolumab was evaluated as a frontline treatment option for patients (pts) with cHL who are over 60 years and ineligible for or declined conventional combination chemotherapy (Friedberg, 2018). The ongoing study reported an ORR of 82% in 11 pts and appears well tolerated in this population. In another trial in 93 patients in the first salvage setting, the combination produced a 67% CR rate (Herrera 2018, Moskowitz 2019) and the majority of patients were able to undergo subsequent stem cell transplant. It is reasonable to expect that the combination of BV, nivolumab, A, and D (AN + AD) will result in high response rates and be well tolerated, with potentially less toxicity. Methods: SGN35-027 (NCT03646123) is a phase 2 study designed to evaluate the efficacy and safety of A+AVD when administered with growth factor prophylaxis in pts with stage III/IV cHL (Part A). Part B will evaluate the combination of AN + AD in a similar patient population. The primary objective of Part B is to estimate the CR rate at EOT in pts with treatment-naïve advanced cHL. Patients in Part B will have Ann Arbor Stage IIB/III/IV cHL or Stage IIA cHL with bulky mediastinal disease. Enrollment is ongoing in both parts of the study. Approximately 50 pts will be enrolled in Part B. All pts will be treated with BV 1.2 mg/kg, nivolumab 240 mg, doxorubicin 25 mg/m², and dacarbazine 375 mg/m², administered separately by IV infusion on Days 1 and 15 of each 28-day cycle for up to 6 cycles. Efficacy will be assessed by PET/CT scans at C2 and EOT. Disease assessments will be performed periodically during follow up. Disease response and progression will be assessed using Lugano with the incorporation of LYRIC (Cheson 2016). Clinical trial information: NCT03646123.