DUBROVNIK, CROATIA—Hematopoietic stem cell transplant (HSCT) can be hit-or-miss in patients with peripheral T-cell lymphomas (PTCLs), according to a speaker at Leukemia and Lymphoma: Europe and the USA, Linking Knowledge and Practice.
Ali Bazarbachi, MD, PhD, of the American University of Beirut in Lebanon, noted that the success of HSCT varies according to the subtype of PTCL and the type of transplant.
For example, autologous (auto) HSCT given as frontline consolidation can be considered the standard of care for PTCL-not otherwise specified (NOS), angioimmunoblastic T-cell lymphoma (AITL), and certain patients with anaplastic large-cell lymphoma (ALCL), according to Dr. Bazarbachi.
On the other hand, auto-HSCT should never be used in patients with adult T-cell leukemia/lymphoma (ATLL).
Both auto-HSCT and allogeneic (allo) HSCT are options for patients with non-localized, extranodal natural killer T-cell lymphoma (ENKTL), nasal type, but only at certain times.
State of PTCL treatment
Dr. Bazarbachi began his presentation by pointing out that patients with newly diagnosed PTCL are no longer treated like patients with B-cell lymphoma, but treatment outcomes in PTCL still leave a lot to be desired.
He noted that, with any of the chemotherapy regimens used, typically, about a third of patients are primary refractory, a third relapse, and a quarter are cured. Only two forms of PTCL are frequently curable—localized ENKTL and ALK-positive ALCL.
Current treatment strategies for PTCL do include HSCT, but recommendations vary. Dr. Bazarbachi made the following recommendations, supported by evidence from clinical trials.
HSCT in PTCL-NOS, AITL, and ALCL
For patients with PTCL-NOS, AITL, or ALK-negative, non-DUSP22 ALCL, auto-HSCT as frontline consolidation can be considered the standard of care in patients who responded to induction, Dr. Bazarbachi said.
In a study published in 20121, high-dose chemotherapy and auto-HSCT as consolidation improved 5-year overall survival—compared to previous results with CHOP2—in patients with ALK-negative ALCL, AITL, PTCL-NOS, and enteropathy-associated T-cell lymphoma.
Allo-HSCT may also be an option for frontline consolidation in patients with PTCL-NOS, AITL, or ALK-negative, non-DUSP22 ALCL, according to Dr. Bazarbachi.
“Allo-transplant is not dead in this indication,” he said. “But it should be either part of a clinical trial or [given] to some selected patients—those with persistent bone marrow involvement, very young patients, or patients with primary refractory disease.”
Results from the COMPLETE study3 showed improved survival in patients who received consolidation with auto- or allo-HSCT, as compared to patients who did not receive a transplant.
COMPLETE patients with AITL or PTCL-NOS had improvements in progression-free and overall survival with HSCT. The survival advantage was “less evident” in patients with ALCL, the researchers said, but this trial included both ALK-negative and ALK-positive patients.
Dr. Bazarbachi noted that allo- and auto-HSCT can be options after relapse in patients with PTCL-NOS, AITL, or ALK-negative, non-DUSP22 ALCL.
However, chemosensitive patients who have relapsed should only receive auto-HSCT if they did not receive it frontline. Patients who have already undergone auto-HSCT can receive allo-HSCT, Dr. Bazarbachi said.
He added that refractory patients should not undergo auto-HSCT and should receive allo-HSCT only within the context of a clinical trial.
HSCT in ATLL
Dr. Bazarbachi noted that ATLL has a dismal prognosis, but allo-HSCT as frontline consolidation is potentially curative.4,5 It is most effective in patients who have achieved a complete or partial response to induction.
However, allo-HSCT should not be given as consolidation to ATLL patients who have received prior mogamulizumab. These patients have an increased risk of morbidity and mortality if they undergo allo-HSCT.
Allo-HSCT should not be given to refractory ATLL patients, although it may be an option for relapsed patients.
Dr. Bazarbachi stressed that ATLL patients should not receive auto-HSCT at any time—as frontline consolidation, after relapse, or if they have refractory disease.
Auto-HSCT “does not work in this disease,” he said. In a study published in 20145, all four ATLL patients who underwent auto-HSCT “rapidly” died.
HSCT in ENKTL
Dr. Bazarbachi said frontline consolidation with auto-HSCT should be considered the standard of care for patients with non-localized ENKTL, nasal type.
Auto-HSCT has been shown to improve survival in these patients6, and it is most effective when patients have achieved a complete response to induction.
Allo-HSCT is also an option for frontline consolidation in patients with non-localized ENKTL, nasal type, Dr. Bazarbachi said.
He added that chemosensitive patients who have relapsed can receive allo-HSCT, but they should only receive auto-HSCT if they did not receive it in the frontline setting. Both types of transplant should take place when patients are in complete remission.
Patients with refractory, non-localized ENKTL, nasal type should not receive auto-HSCT, but allo-HSCT is an option, Dr. Bazarbachi said.
He did not declare any conflicts of interest.
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