Auto-HSCT ‘still relevant’ for chemosensitive, relapsed diffuse large B-cell lymphoma
Autologous hematopoietic stem cell transplant conferred survival outcomes comparable to chimeric antigen receptor T-cell therapy for certain patients with lymphoma, according to results presented during the ASCO20 Virtual Scientific Program.
There is still a role for autologous HSCT in the era of CAR T-cell therapy for patients with relapsed diffuse large B-cell lymphoma and evidence of disease after salvage therapies who also are chemosensitive, researchers concluded.
Autologous HSCT is the current standard of care for patients with chemosensitive, relapsed DLBCL, researcher Nirav N. Shah, MD, assistant professor of hematology and medical oncology at Medical College of Wisconsin and a HemOnc Today Next Gen Innovator, told Healio.
“From 2017 to 2018 there was a huge drop in the use of autologous stem cell transplants, and it has been suggested that the availability of autologous CAR T-cell therapy is responsible for the decrease of autologous stem cell transplants,” he said.
A large proportion of patients who are not in complete remission before a planned autologous HSCT are opting for CAR T-cell therapy instead, Shah said.
“We were trying to look at this population, who were not yet in remission but who also had documented chemosensitive disease ... and we found that, in this patient population, autologous stem cell transplant still has 5-year PFS of 41%, which is comparable to CAR T-cell therapy,” he said.
Shah and colleagues used the Center for International Blood and Marrow Transplant Research (CIBMTR) registry to obtain data of 249 patients with relapsed DLBCL who underwent autologous HSCT between 2003 and 2013. Patients had evidence of disease via PET/CT before transplant.
Researchers divided the study population into two cohorts. One included 182 patients who relapsed early — defined as less than 1 year — after receiving rituximab (Rituxan; Genentech, Biogen). The other included 67 patients who relapsed late — 1 year or longer — after receiving rituximab.
Patient characteristics appeared similar between the groups, with those in the late chemoimmunotherapy failure group tending to be older (median age, 62.86 years vs. 57.16 years; P < .001). A higher percentage of patients with early relapse had stage III or stage IV disease at diagnosis (74% vs 54%; P = .003).
All patients had a median two (range, 1-5) lines of previous therapy.
OS served as the study’s primary outcome, with secondary outcomes that included PFS and relapse.
Patients who relapsed early had a 5-year adjusted PFS rate of 41%, which was identical to the PFS rate in the late relapse group. Five-year OS rates were 51% in the early relapse group and 63% in the late relapse group.
A multivariate analysis showed patients with early relapse had an increased risk for death compared with those who had late relapse (HR = 1.61; 95% CI, 1.05-2.46). The analysis showed no increased risk for PFS or relapse between the two groups.
“Autologous transplant is still relevant in patients with chemosensitive, relapsed diffuse large B-cell lymphoma,” Shah told Healio. “Before we replace autologous transplant with CAR-T, we should wait for results from randomized studies that show one approach is superior to the other in this patient population.”
Shah noted the possibility that CAR T-cell therapy could make autologous HSCT obsolete in the future but, for now, the data show comparable long-term outcomes.
“It may be that auto-transplant remains an effective tool for patients with chemosensitive, relapsed diffuse large B-cell lymphoma,” Shah said. “We should be mindful about replacing this therapy with another before seeing data that is superior or at least equivalent.”