study, the outcomes were reported for 39
patients who underwent allo-HCT after prior
therapy with a PD-1 inhibitor. Three patients
( 7.7%) developed lethal acute GVHD, suggesting there may be an increased risk of GVHD in
patients undergoing allo-HCT after prior PD-1
inhibitor therapy.72
AUTOLOGOUS STEM CELL TRANSPLANTATION
Several studies have shown an improved disease-free survival (DFS) or FFS in patients with
relapsed cHL treated by auto-HCT as compared
to those receiving conventional chemotherapy
alone.55,73,74 Overall, for relapsed disease, one
can expect an approximately 50% to 60%
chance for DFS at 5 years post-transplant. In a
retrospective, matched-pair analysis, FFP was
62% for auto-HCT patients, compared to 32%
for conventional chemotherapy patients. OS,
however, was similar for the 2 groups (47%–
54%). Patients failing induction therapy or
relapsing within 1 year were seen to benefit the
most from auto-HCT, including an OS benefit.74
A European prospective randomized trial
was conducted comparing conventional salvage therapy to auto-HCT. In this study, 161
patients with relapsed Hodgkin lymphoma were
treated with 2 cycles of dexa-BEAM. Those with
chemo-sensitive disease were then randomized
to either 2 more cycles of dexa-BEAM or high-dose BEAM with auto-HCT. Auto-HCT was
associated with an approximately 55% FFTF at
3 years, versus 34% with conventional chemotherapy alone.55 This benefit again was most
apparent for patients relapsing within 1 year of
completion of primary therapy, although an OS
benefit was not seen with auto-HCT. For patients
with late relapse (>1 year after completion of
primary therapy), auto-HCT was associated with
an approximately 75% FFTF at 3 years, versus
50% with chemotherapy alone. One other small
randomized trial of auto-HCT in relapsed and
refractory Hodgkin lymphoma also showed an
improved 3-year EFS in favor of auto-HCT (53%
versus 10%), again with no difference in OS.73
The lack of OS benefit seen in these stud-
ies suggests that auto-HCT at first or second
relapse provides comparable outcomes. Auto-
HCT offers the benefit of avoiding the long-
term toxicities associated with multiple salvage
regimens and the anxiety associated with mul-
tiple relapses. In addition, the treatment-related
mortality with auto-HCT is now in the 1% to
2% range in younger patients, at centers that
perform the procedure routinely. For all of
these reasons, auto-HCT is commonly recom-
mended by physicians for Hodgkin lymphoma
patients in first or second relapse. In most cases,
transplant is favored in first relapse, since wait-
ing until second relapse may be associated with
a lower chance of achieving CR and difficulty
collecting sufficient hematopoietic stem cells.
For patients with early relapse or primary refrac-
tory disease, an even stronger case can be made
for auto-HCT as the best option to achieve sus-
tained control of the disease. For patients with
late relapse, conventional salvage therapy alone
may be a reasonable option, particularly in
older or frail patients, or those with significant
comorbid conditions.
The optimal conditioning regimen for auto-
HCT for relapsed and refractory Hodgkin lym-
phoma remains undefined. No randomized
trials have been performed comparing con-
ditioning regimens for relapsed and refrac-
tory Hodgkin lymphoma. One retrospective
study compared 92 patients with Hodgkin lym-
phoma who underwent auto-HCT using a total-
body irradiation (TBI) regimen versus a
chemotherapy-alone regimen. No difference
in 5-year OS or EFS was seen.75 Given the lack
of benefit seen with TBI, along with reports
of increased rates of secondary malignancies
and myelodysplasia with TBI,76 chemotherapy-
alone conditioning regimens are most widely
employed. For example, in the United States,
either the BEAM or CBV (cyclophosphamide,
carmustine, etoposide) regimens are used in
over 80% of cases.77 This practice was justified
in a Center for International Blood and Marrow