PRIMARY OBJECTIVES:
I. Demonstrate the non-inferiority (and possible superiority) in progression free survival (PFS) amongst patients with relapsed/refractory classical Hodgkin lymphoma (R/R cHL) after checkpoint inhibitor-based maintenance and localized radiation in comparison to standard of care HDT-ASCT. (Phase III Standard-Risk) II. Demonstrate the superiority of checkpoint inhibitor-based maintenance after HDT-ASCT in improving PFS among patients with R/R cHL in comparison to standard of care HDT-ASCT. (Phase II High-Risk)
SECONDARY OBJECTIVES:
I. To assess overall survival (OS) in the treatment arms in the standard risk as well as high-risk groups.
II. To assess safety and toxicity of the treatment regimens in the standard risk as well as high risk groups.
EXPLORATORY OBJECTIVES:
I. To evaluate prognostic factors (lactate dehydrogenase \[LDH\], erythrocyte sedimentation rate \[ESR\], time to relapse, B symptoms, extranodal disease, stage, bulk, treatment with a checkpoint inhibitor, response at the time of ASCT) associated with risk of progression following HDT-ASCT (Arms B and D).
II. To compare the impact of various radiation therapy modalities utilized (e.g., 3-dimensional conformal radiation therapy \[3D-CRT\], intensity-modulated radiation therapy \[IMRT\], proton therapy) and its association with dosimetric and clinical outcomes, including toxicity assessment, (grade 2+), at the end of radiation.
III. To assess PFS for patients in partial metabolic response (PMR) receiving radiation therapy, compared to those patients in complete metabolic response (CMR), for all arms of the study.
OUTLINE: Patients in the standard risk cohort are assigned to Arm S and patients in the high risk cohort are assigned to Arm H.
ARM S: Patients receive standard of care salvage therapy for up to 2-4 cycles per investigator choice. After completing salvage therapy, patients without stable disease (SD) or progressive metabolic disease (PMD) are randomized to Arm A or Arm B.
ARM A: Patients undergo photon RT with either 3DCRT, IMRT, volume modulated arc therapy (VMAT), or tomotherapy or proton RT with either passive scattering, uniform scanning, or pencil beam scanning over 15-17 fractions. Starting 4-8 weeks after completing radiation therapy, patients receive brentuximab vedotin intravenously (IV) over 30 minutes and nivolumab IV over 30 minutes on day 1 of each cycle. Cycles repeat every 21 days for up to 4 cycles in the absence of disease progression or unacceptable toxicity. Patients then receive nivolumab for an additional 2 cycles in the absence of disease progression or unacceptable toxicity.
ARM B: Patients receive HDT and undergo ASCT per standard of care in the absence of disease progression or unacceptable toxicity. Starting within 4-8 weeks after transplant, patients with CMR may also undergo RT as in arm A over 15-17 fractions and patients with PMR may also undergo RT over 20-22 fractions per investigator. Starting 30-45 days after transplant, patients may also receive maintenance treatment with brentuximab vedotin for up to 16 cycles in the absence of disease progression or unacceptable toxicity as determined per investigator at time of randomization.
ARM H: Patients receive 2-4 cycles of standard of care salvage therapy per investigator choice. After completing salvage therapy, patients without SD or PMD are randomized to Arm C or Arm D.
ARM C: Patients receive HDT and undergo ASCT per standard of care. Starting 4-8 weeks after transplant, patients receive pembrolizumab IV over 30 minutes on day 1 of each cycle. Cycles repeat every 21 days for up to 8 cycles in the absence of disease progression or unacceptable toxicity. Starting within 4-8 weeks after transplant, patients with CMR may also undergo RT as in arm A over 15-17 fractions and patients with PMR may also undergo RT over 20-22 fractions per investigator. Starting 30-45 days after transplant, patients may also receive maintenance treatment with brentuximab vedotin for up to 16 cycles in the absence of disease progression or unacceptable toxicity as determined per investigator at time of randomization.
ARM D: Patients receive HDT and undergo ASCT per standard of care in the absence of disease progression or unacceptable toxicity. Starting within 4-8 weeks after transplant, patients with CMR may also undergo RT as in arm A over 15-17 fractions and patients with PMR may also undergo RT over 20-22 fractions per investigator. Starting 30-45 days after transplant, patients may also receive maintenance treatment as in arm B in the absence of disease progression or unacceptable toxicity as determined per investigator at time of randomization.
Additionally, patients may undergo blood sample collection, computed tomography (CT), and positron emission tomography (PET)/CT throughout the study.
After completion of study treatment, patients are followed every 6 months for the first 2 years then annually for up to 15 years.