Allogeneic stem cell transplantation (alloSCT) represents a curative option for patients with relapsed/refractory (r/r) aggressive lymphomas. We compared outcomes of alloSCT in r/r PTCL and r/r DLBCL pts (n = 150) who underwent identical myeloablative conditioning chemotherapy, GvHD prophylaxis, and relapse management. 5-year PFS and OS were significantly superior in PTCL compared to DLBCL (56% vs. 24%; 56% vs. 28%; p ≤ 0.005). A landmark analysis (day≥ +100 post-alloSCT) markedly favored outcomes in PTCL vs. DLBCL: 5-year PFS and OS of 76% vs. 30% and 76% and 35%, respectively (p ≤ 0.003). Non-relapse mortality was comparable (35% PTCL vs. 34% DLBCL, p = 0.894), whereas post-alloSCT relapse mortality was significantly higher in DLBCL (36% vs. 10%, p = 0.0007). The occurence of limited chronic GvHD did not improve outcomes in DLBCL, whereas extensive chronic GvHD was a negative risk factor for both (HR 2.09 and 2.80, p ≤ 0.006). In conclusion, we gained evidence for strong graft-versus-lymphoma activity against PTCL but not DLBCL.

This study investigated the efficacy of tisagenlecleucel (tisa-cel) and allogeneic hematopoietic stem cell transplantation (allo-SCT) for patients with relapsed and/or refractory (r/r) large B-cell lymphoma (LBCL) with poor prognostic factors, defined as performance status (PS) ≥ 2, multiple extranodal lesions (EN), chemorefractory disease, or higher lactate dehydrogenase (LDH). Overall, the allo-SCT group demonstrated worse progression-free survival (PFS), higher non-relapse mortality, and a similar relapse/progression rate. Notably, the tisa-cel group showed better PFS than the allo-SCT group among patients with chemorefractory disease (3.2 vs. 2.0 months, p = 0.092) or higher LDH (4.0 vs. 2.0 months, p = 0.018), whereas PFS in the two cellular therapy groups was similar among those with PS ≥ 2 or multiple EN. Survival time after relapse post-cellular therapy in patients with poor prognostic factors was 1.6 with allo-SCT and 4.6 months with tisa-cel. These findings were confirmed in a propensity score matching cohort. In conclusion, tisa-cel resulted in better survival than allo-SCT in patients with poor prognostic factors. However, patients who relapsed post-cellular therapy had dismal outcomes regardless of therapy. Further strategies are warranted to improve outcomes in these patients.

Allogeneic haematopoietic stem cell transplantation (allo-HSCT) is a curative option for relapse/refractory (R/R) lymphomas that have failed autologous transplantation or for high-risk lymphomas in the upfront setting. We conducted a retrospective analysis on consecutive lymphoma patients who underwent allo-HSCT over a 20-year period (2003- 2022) at Singapore General Hospital and National University Hospital Singapore.

A total of 121 patients were included in the study. Median age was 41 years. Diagnoses include Hodgkin lymphoma (HL, 15%), B-cell non- Hodgkin lymphoma (B-NHL, 34%), T-cell non-Hodgkin lymphoma (T-NHL, 31%) and natural killer T-cell lymphoma (NKTL, 20%). Moreover, 27% of patients had prior auto-haematopoietic stem cell transplanta-tion (auto-HSCT), and 84% received reduced intensity conditioning (RIC). Donor types were matched sibling donor (45%), matched unrelated donor (29%), haploidentical donor (19%) and cord blood (CB, 7%).

After median follow-up of 56 months, estimated 4-year progression-free survival (PFS) and overall survival (OS) for all patients were 38% and 45%, respectively. Non-relapse mortality (NRM) was 15% at day 100 and 24% at 1 year. On univariate analysis, complete remission status at transplant and RIC confers superior OS. On multivariate analysis, HL was associated with superior OS compared to NHL, whereas matched unrelated donor transplant was associated with significantly inferior OS compared to matched sibling donor.

Long-term curative durability was observed with allo-HSCT for patients with relapsed/ refractory lymphomas. This real-world data serves as a valuable historical benchmark for future studies on lymphomas in Singapore and the Asia Pacific region.

Autologous(auto-) and allogeneic(allo-) hematopoietic stem cell transplantation (HSCT) are key treatments for relapsed/refractory diffuse large B-cell lymphoma (DLBCL), although their roles are challenged by CAR-T-cells and other immunotherapies. We examined the transplantation trends and outcomes for DLBCL patients undergoing auto-/allo-HSCT between 1990 and 2021 reported to EBMT. Over this period, 41,148 patients underwent auto-HSCT, peaking at 1911 cases in 2016, while allo-HSCT saw a maximum of 294 cases in 2018. The recent decline in transplants corresponds to increased CAR-T treatments (1117 cases in 2021). Median age for auto-HSCT rose from 42 (1990-1994) to 58 years (2015-2021), with peripheral blood becoming the primary stem cell source post-1994. Allo-HSCT median age increased from 36 (1990-1994) to 54 (2015-2021) years, with mobilized blood as the primary source post-1998 and reduced intensity conditioning post-2000. Unrelated and mismatched allo-HSCT accounted for 50% and 19% of allo-HSCT in 2015-2021. Three-year overall survival (OS) after auto-HSCT improved from 56% (1990-1994) to 70% (2015-2021), p < 0.001, with a decrease in relapse incidence (RI) from 49% to 38%, while non-relapse mortality (NRM) remained unchanged (4%). After allo-HSCT, 3-year-OS increased from 33% (1990-1999) to 46% (2015-2021) (p < 0.001); 3-year RI remained at 39% and 1-year-NRM decreased to 19% (p < 0.001). Our data reflect advancements over 32 years and >40,000 transplants, providing insights for evaluating emerging DLBCL therapies.

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is still a potentially curative option for B-cell Non-Hodgkin Lymphoma (B-NHL) in the modern immunotherapy era. The objective of this study was to analyze long-term outcomes of patients with B-NHL who received allo-HSCT. We analyzed overall survival (OS), progression-free survival (PFS) and graft versus host disease (GVHD) relapse-free survival (GRFS) in 53 patients undergoing allo-HSCT from two institutions. The median follow-up of the study was 72 months (range 29-115 months). The median number of lines of therapy before allo-HSCT was 3 (range 1-6) and twenty-eight patients (53%) had received a previous autologous transplant. The 3-year PFS, OS and GRFS were 55%, 63%, and 55%, respectively. One-year non-relapse mortality was 26%. Karnofsky Performance Scale < 90 was associated with worse OS in multivariable analysis. A non-comparative analysis of a cohort of 44 patients with similar characteristics who received chimeric antigen receptor T-cell therapy was done, showing a 1-year PFS and OS were 60% and 66%, respectively. Our data shows that allo-HSCT is still a useful option for treating selected patients with R/R B-NHL. Our retrospective analysis and review of the literature demonstrate that allo-HSCT can provide durable remissions in a subset of patients with R/R B-NHL.

Radiotherapy (RT) is an effective and available local treatment for patients with refractory or relapsed (R/R) aggressive B-cell lymphomas. However, the value of hypofractionated RT in this setting has not been confirmed.

We retrospectively analyzed patients with R/R aggressive B-cell lymphoma who received hypofractionated RT between January 2020 and August 2022 at a single institution. The objective response rate (ORR), overall survival (OS), progression-free survival (PFS) and acute side effects were analyzed.

A total of 30 patients were included. The median dose for residual disease was 36 Gy, at a dose per fraction of 2.3-5 Gy. After RT, the ORR and complete response (CR) rates were 90% and 80%, respectively. With a median follow-up of 10 months (range, 2-27 months), 10 patients (33.3%) experienced disease progression and three died. The 1-year OS and PFS rates for all patients were 81.8% and 66.3%, respectively. The majority (8/10) of post-RT progressions involved out-of-field relapses. Patients with relapsed diseases, no response to systemic therapy, multiple lesions at the time of RT, and no response to RT were associated with out-of-field relapses. PFS was associated with response to RT (P = 0.001) and numbers of residual sites (P < 0.001). No serious non-hematological adverse effects (≥ grade 3) associated with RT were reported.

These data suggest that hypofractionated RT was effective and tolerable for patients with R/R aggressive B-cell lymphoma, especially for those that exhibited localized residual disease.

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is considered for patients with high-risk B-cell lymphoma and relapsed or refractory disease. This study aimed to analyze the long-term follow-up data of patients who underwent allo-HSCT in Taiwan. This was a retrospective observational study using data from the Taiwan Society of Blood and Marrow Transplantation database. A total of 105 patients who underwent allo-HSCT because of high-risk, relapsed, or refractory disease between 2010 and 2019 were included. Forty-five percent of the patients previously underwent autologous stem cell transplantation (ASCT). The median follow-up duration was 18.6 months. The probability of 3-year progression-free survival and overall survival (OS) was 34.5% and 37%, respectively. The probability of 1-year non-relapse mortality was 31.4%, and the major cause was infection (75.8%). The multivariable analysis showed that not in remission at the time of transplantation and the absence of graft-versus-host disease (GVHD) were factors associated with inferior OS. The probability of 3-year OS in patients with diffuse large B-cell lymphoma who underwent allo-HSCT and allo-HSCT after ASCT was 40.2% and 25.2%, respectively. Allo-HSCT could be a salvage therapeutic option for relapsed or refractory B-cell lymphoma. Complete remission at the time of allo-HSCT and the presence of GVHD are independent variables for overall survival.

To clarify the role of allogeneic hematopoietic stem-cell transplantation (allo-HSCT) in the chimeric antigen receptor T-cell therapy era, we analyzed the clinical characteristics and outcomes of 52 patients treated with allo-HSCT with relapsed/refractory diffuse large B cell lymphoma. Most enrolled patients had previously undergone intensive treatments, the median number of chemotherapy lines was 4, and the median time from diagnosis to allo-HSCT was 27.1 months. Patients were divided into remission-achieved (n = 30) and active-disease (n = 22) groups before allo-HSCT. Over a median follow-up period of 38.3 months, overall survival (OS) and event-free survival (EFS) rates were 38.4% and 30.6%, respectively. The cumulative incidence of relapse (CIR) and the non-relapsed mortality (NRM) were 36.7% and 32.7%, respectively. OS, EFS, and graft-versus-host disease-free, relapse-free survival (GRFS) outcomes were significantly superior in the remission-achieved group with lower CIR. In a multivariate analysis, a shorter interval from diagnosis to allo-HSCT reflected relatively rapid disease progression and showed significantly poor OS and EFS with higher CIR. Patients with active disease had significantly lower EFS, GRFS, and higher CIR. Previous autologous stem-cell transplantation was associated with better GRFS. Allo-HSCT is an established modality with a prominent group of cured patients and still has a role in the CAR T-cell era, particularly given its acceptable clinical outcomes in young patients with chemo-susceptible disease.

Anti-CD19 chimeric antigen receptor T cells (CART) has rapidly been adopted as the standard third-line therapy to treat aggressive B-cell lymphomas (ABCL) after failure of second-line therapy despite the lack of direct comparisons with allogeneic hematopoietic cell transplantation (alloHCT)-based strategies. Using the Grupo Español de Trasplante y Terapia Celular (GETH-TC) registry, we selected patients with the following characteristics: CART or alloHCT performed between 2016 and 2021; ≥18 years old; ABCL diagnosis; ≥2 lines of therapy; and either anti-CD19 CART or alloHCT as therapy at relapse. The analysis included a total of 316 (CART = 215, alloHCT = 101) patients. Median follow-up was 15 and 36 months for the CART and alloHCT cohorts, respectively. In the multivariate analysis, CART was confirmed to be similar to alloHCT for the primary study endpoint (progression-free survival) (hazard ratio [HR] 0.92, CI95%:0.56-1.51, p = 0.75). Furthermore, when the analysis was limited to only patients with chemo-sensitive diseases (complete and partial response) at infusion (CART = 26, alloHCT=93), no differences were reported (progression-free survival at month +18: 65% versus 55%, p = 0.59). However, CART had lower non-relapse mortality (HR 0.34, 95% CI: 0.13-0.85, p = 0.02). Given the lower toxicity and similar survival outcomes, these results suggest the use of CART before alloHCT.

Anti-CD19 chimeric antigen receptor T cell (CAR-T) therapy has transformed the care of patients with relapsed/refractory large B cell lymphoma (LBCL). However, approximately 60% of CAR-T recipients ultimately will experience disease recurrence or progression. Salvage therapies after CAR-T treatment failures are of limited efficacy and have a short duration of response. The objective of the present study was to evaluate the role of allogeneic hematopoietic cell transplantation (allo-HCT) after CAR-T therapy in LBCL patients. This was a multicenter observational study reporting the outcome of 39 adult LBCL patients who underwent allo-HCT following anti-CD19 CAR-T therapy. The median patient age was 47 years (range, 20 to 68 years). HLA-matched sibling, HLA-matched unrelated, and alternative donors were used in 36%, 36%, and 28% of transplantations, respectively. Conditioning regimens were primarily of low or intermediate intensity. Disease status at allo-HCT was complete response in 41%, partial response in 38%, and progressive disease in 21%. Allo-HCT was performed at a median of 127 days (range, 82 to 206 days) after CAR-T therapy. A high incidence of hepatic toxicity (28%), including sinusoidal obstruction syndrome (15.4%; 95% confidence interval; [CI], 6.2% to 28.5%), was observed. The 1-year cumulative incidence of grade II-IV and grade III-IV acute graft-versus-host disease (GVHD) was 38.5% (95% CI, 23.2% to 53.6%) and 15.4% (95% CI, 6.1% to 28.5%), respectively. The 2-year cumulative incidence of moderate-severe chronic GVHD was 11.1% (95% CI, 3.3% to 24.3%). Overall, 2-year nonrelapse mortality and relapse/progression incidence were 26% (95% CI, 13% to 41%) and 43% (95% CI, 27% to 59%), respectively. With a median follow-up of 32 months, the 2-year overall survival (OS) and progression-free survival (PFS) were 45% (95% CI, 31% to 66%) and 31% (95% CI, 19% to 50%), respectively. In multivariable analyses, pre-HCT elevated lactate dehydrogenase level and transformed lymphoma were predictive of OS and PFS, respectively. Our data suggest that allo-HCT after anti-CD19 CAR-T treatment failure is feasible with a relatively promising efficacy but possibly high toxicity rate.

Transformation of follicular lymphoma into an aggressive lymphoma (tFL) worsens the prognosis and the standard treatment is not completely defined. Allogeneic hematopoietic stem cell transplantation (alloSCT) could be a potentially curative option for these patients, but it has not been widely explored.

We designed a retrospective multicenter study to analyze the efficacy and toxicity of alloSCT in tFL patients and potential prognostic factors of survival.

A total of 43 patients diagnosed with tFL who underwent alloSCT in 14 Spanish centers between January 2000 and January 2019 were included. Median age was 44 (31-67) years. After a median follow-up of 58 months, estimated 5-year overall survival (OS) and progression-free survival (PFS) were both 35%. Estimated 100-day and 1-year non-relapse mortality (NRM) were 20% and 34%, respectively. The type of conditioning regimen (3-year OS of 52% vs. 20%, respectively, for reduced-intensity vs. myeloablative conditioning) and development of chronic graft versus host disease (cGVHD) (3-year OS of 75% vs. 40%) were the only factors significantly associated with OS. The only variable with an independent association with OS was cGVHD (HR, 3.4; 95% CI, 1.2-9.6).

Our results indicate that alloSCT continues to be a potentially curative option for patients with tFL.

CD19 CAR T-cells represent a practice-changing treatment modality for advanced B-cell malignancies. However, refractory cytopenias have emerged as a potentially life-threatening complication that can persist long after lymphodepleting chemotherapy. Whether stem cell rescue is feasible and efficacious after CAR-T has not been addressed. In this retrospective multi-center study, we describe clinical characteristics and outcomes of 13 patients with hyporegenerative bone marrow (BM) failure after CD19 CAR-T, which received a previously collected stem cell graft (10 autologous, 3 allogeneic) to rescue cytopenias. Interestingly, patients already presented with impaired hematopoietic function and high levels of systemic inflammation prior to lymphodepleting chemotherapy, as reflected by high CAR-HEMATOTOX scores (median 4). The median duration of severe neutropenia prior to stem cell boost was 41 days (interquartile range 16-50). The indication for boost was severe pancytopenia (aplasia) in 7 cases and persistent isolated neutropenia/thrombocytopenia in 6 cases. Median day of stem cell boost was day 55 after CAR-T (median 3.1x106/kg CD34+ cells). Engraftment rates were high (neutrophil: 92%, platelet: 70%), with a median time to neutrophil- and platelet engraftment of 15 and 21 days, respectively. Two patients died of invasive fungal infections (day 4 and 17 after stem cell boost). The 1-year progression-free (PFS) and overall survival (OS) rates were 42% and 51%, respectively. These data indicate that the transplantation of available stem cell products for post-CAR-T cytopenias is clinically feasible, safe and efficacious. Further studies are needed to assess, whether a pre-emptive collection of stem cells can be justified in selected high-risk patients.