Autologous stem cell transplant in fit patients with refractory or early relapsed diffuse large B-cell lymphoma that responded to salvage chemotherapy.

Chimeric antigen receptor T-cell therapy is the new standard of care in fit patients with refractory or early relapsed diffuse large B-cell lymphoma (DLBCL). However, there may still be a role for salvage chemotherapy (ST) and autologous stem cell transplant (ASCT) in certain circumstances (e.g., lack of resources for chimeric antigen receptor T-cell therapy, chemosensitive relapses). We retrospectively studied 230 patients with refractory or early relapsed DLBCL who underwent ST and ASCT. The median line of ST was one (range, 1-3). Best response before ASCT was complete response in 106 (46%) and partial response in 124 (54%) patients. The median follow-up after ASCT was 89.4 months. The median progression-free (PFS) and overall survival (OS) were 16.1 and 43.3 months, respectively. Patients relapsing between 6 to 12 months after frontline therapy had a numerically better median PFS (29.6 months) and OS (88.5 months). Patients who required one line of ST, compared to those requiring more than one line, had a better median PFS (37.9 vs. 3.9 months; P=0.0005) and OS (68.3 vs. 12.0 months; P=0.0005). Patients who achieved complete response had a better median PFS (71.1 vs. 6.3 months; P<0.0001) and OS (110.3 vs. 18.9 months; P<0.0001) than those in partial response. Patients who achieved complete response after one line of ST had the most favorable median PFS (88.5 months) and OS (117.2 months). Post-ASCT survival outcomes of patients with refractory or early relapsed DLBCL appeared reasonable and were particularly favorable in those who required only one line of ST to achieve complete response before ASCT, highlighting the role of this procedure in select patients with chemosensitive disease.

Impact of hypoalbuminemia on the prognosis of relapsed/refractory B-cell lymphoma treated with axicabtagene ciloleucel.

INTRODUCTION: Hypoalbuminemia is a known adverse prognostic factor in lymphomas. Yet, it is unknown if axicabtagene ciloleucel (axi-cel) overcomes the adverse prognostic impact of hypoalbuminemia in relapsed/refractory large B-cell lymphoma. METHODS: We conducted a retrospective analysis across three Mayo Clinic centers to assess the relationship of hypoalbuminemia (defined as a serum albumin (SA) levels ≤ 3.5 g/dL) on outcomes of patients treated with axi-cel. RESULTS: This analysis included 81 patients. Two patients had no available SA levels preceding axi-cel infusion. Eighteen patients (22.8%) had hypoalbuminemia with a median SA of 3.3 g/dL. Patients with normal SA had a statistically higher ORR than those without hypoalbuminemia (P = .018). There was no difference in 1-year PFS and OS between the group with hypoalbuminemia and the group with normal SA levels (48% vs 49%, P = .81) and (74% vs 73%, P = .97), respectively. There was no difference in the severity or median duration of cytokine release syndrome or neurotoxicity between the two groups. CONCLUSION: Notwithstanding the limitations related to the relatively small sample size, axi-cel therapy appears to overcome the adverse effect of hypoalbuminemia on OS and PFS. Large multicenter clinical studies are certainly needed to validate these findings.

Procalcitonin as a biomarker for predicting bacterial infection in chimeric antigen receptor T-cell therapy recipients.

BACKGROUND: It is unknown whether serum procalcitonin (PCT) concentration monitoring can differentiate between bacterial infection or cytokine release syndrome (CRS) when chimeric antigen receptor T-cell (CAR-T) recipients present with a constellation of signs and symptoms that may represent both complications. OBJECTIVE: The objective of the study was to assess the utility of serum PCT concentrations as a biomarker of bacterial infection in CAR-T recipients. STUDY DESIGN: This single-center, retrospective, medical record review evaluated patients prescribed CAR-T therapy until death or 30 days after infusion. Logistic regression modeling determined the association between elevated serum PCT concentrations within 48 h of fever onset and microbiologically confirmed infection. Secondary outcomes included clinically suspected infection, CAR-T toxicity rates, and broad-spectrum antibiotic usage. Predictive performance of PCT was assessed by area under the receiver operating characteristic curve (AUC). RESULTS: The 98 included patients were a median age of 63 (IQR: 55-69) years old, 47 (48%) were male, and 87 (89%) were Caucasian. Baseline demographics and clinical characteristics were similar between patients with and without a bacterial infection. Serum PCT >0.4 ng/mL within 48 h of fever was significantly associated with a microbiologically confirmed bacterial infection (OR: 2.75 [95% CI: 1.02-7.39], p = 0.045). Median PCT values in patients with and without confirmed infections were 0.40 ng/mL (IQR: 0.26, 0.74) and 0.26 ng/mL (IQR: 0.13, 0.47), respectively. The AUC for PCT to predict bacterial infection was 0.62 (95% CI 0.48-0.76). All patients experienced CRS of some grade, with no difference in CRS severity based on elevated PCT. Broad-spectrum antibiotics were used for a median of 45% and 23% of days in those with and without confirmed infection, respectively (p = 0.075). CONCLUSION: Elevated serum PCT concentrations above 0.4 ng/mL at time of first fever after CAR-T infusion was significantly associated with confirmed bacterial infection. Furthermore, rigorous, prospective studies should validate our findings and evaluate serial PCT measurements to optimize antimicrobial use after CAR-T therapy.

Characterization of immune exhaustion and suppression in the tumor microenvironment of splenic marginal zone lymphoma.

The role of the tumor microenvironment (TME) and intratumoral T cells in splenic marginal zone lymphoma (sMZL) is largely unknown. In the present study, we evaluated 36 sMZL spleen specimens by single cell analysis to gain a better understanding of the TME in sMZL. Using mass cytometry (CyTOF), we observed that the TME in sMZL is distinct from that of control non-malignant reactive spleen (rSP). We found that the number of TFH cells varied greatly in sMZL, ICOS+ TFH cells were more abundant in sMZL than rSP, and TFH cells positively correlated with increased numbers of memory B cells. Treg cell analysis revealed that TIGIT+ Treg cells are enriched in sMZL and correlate with suppression of TH17 and TH22 cells. Intratumoral CD8+ T cells were comprised of subsets of short-lived, exhausted and late-stage differentiated cells, thereby functionally impaired. We observed that T-cell exhaustion was present in sMZL and TIM-3 expression on PD-1low cells identified cells with severe immune dysfunction. Gene expression profiling by CITE-seq analysis validated this finding. Taken together, our data suggest that the TME as a whole, and T-cell population specifically, are heterogenous in sMZL and immune exhaustion is one of the major factors impairing T-cell function.

Metabolic PET/CT analysis of aggressive Non-Hodgkin lymphoma prior to Axicabtagene Ciloleucel CAR-T infusion: predictors of progressive disease, survival, and toxicity.

PET/CT is used to evaluate relapsed/refractory non-Hodgkin lymphoma (NHL) prior to chimeric antigen receptor T-cell (CAR-T) infusion at two time points: pre-leukapheresis (pre-leuk) and pre-lymphodepletion chemotherapy (pre-LD). We hypothesized that changes in PET/CT between these time points predict outcomes after CAR-T. Metabolic tumor volume (MTV), total lesion glycolysis (TLG), and other metrics were calculated from pre-leuk and pre-LD PET/CT scans in patients with NHL who received axicabtagene ciloleucel, and assessed for association with outcomes. Sixty-nine patients were analyzed. While single time point PET/CT characteristics were not associated with risk of PD or death, increases from pre-leuk to pre-LD in parenchymal MTV, nodal MTV, TLG of the largest lesion, and total number of lesions were associated with increased risk of death (p < 0.05 for all). LASSO analysis identified increasing extranodal MTV and increasing TLG of the largest lesion as strong predictors of death (AUC 0.74). Greater pre-LD total MTV was associated with higher risk of grade 3+ immune effector cell-associated neurotoxicity syndrome (ICANS) (p = 0.042). Increasing metabolic disease burden during CAR-T manufacturing is associated with increased risk of progression and death. A two variable risk score stratifies prognosis prior to CAR-T infusion and may inform risk-adapted strategies.

Outcomes of Patients With Classic Hodgkin Lymphoma Who Relapsed After Autologous Stem Cell Transplant.

Immune checkpoint inhibitors (ICIs) and brentuximab vedotin (BV) are novel agents for classic Hodgkin lymphoma, including relapse after autologous stem cell transplant (ASCT). However, their impact on survival post-ASCT relapse, in comparison with conventional therapy, is less known due to the lack of randomized controlled trials. Clinical characteristics and outcomes of 115 patients with relapse (or progression) after ASCT are studied. After a median follow-up of 8.59 years from post-ASCT relapse, the median progression-free survival (PFS) and overall survival (OS) were 0.91 and 5.07 years, respectively. Median lines of therapy after post-ASCT relapse was 2 (range, 1-12). The median PFS was not reached (NR) versus 1.11 versus 0.50 versus 0.85 versus 0.78 years (P = 0.006) and OS was NR versus 7.60 versus 3.08 versus 3.51 versus 3.17 years (P = 0.28) in patients first treated with ICIs versus BV versus investigational agents versus chemotherapy versus radiation therapy (RT). First-line treatment with novel agents (ie, ICIs and BV) was associated with superior outcomes compared with investigational agents and chemotherapy/RT with a median PFS of 1.65 versus 0.50 versus 0.79 years (P = 0.003) and a median OS of 7.60 versus 3.08 versus 3.32 years (P = 0.08). Regardless of lines of therapy, the treatment with ICIs had the most favorable outcome with a median PFS and OS of 3.98 and NR years, respectively. Allogeneic stem cell transplant (allo-SCT) was done in 23 patients (20%), and the median post-allo-SCT PFS and OS were 1.31 and 2.35 years, respectively. In conclusion, survival following post-ASCT relapse improves significantly when patients receive novel agents.

Progression-Free Survival at 24 Months as A Landmark After Autologous Stem Cell Transplant in Relapsed or Refractory Diffuse Large B-cell Lymphoma.

Patients with newly diagnosed diffuse large B-cell lymphoma (DLBCL) who achieve progression-free survival (PFS) at 24 months (PFS24) after immunochemotherapy (IC) have excellent overall survival (OS) comparable to that of the age- and sex-matched general population. However, a similar landmark has not been established for patients with relapsed or refractory (RR) DLBCL following frontline IC who are subsequently treated with salvage therapy followed by autologous stem cell transplantation (ASCT). To evaluate the role of PFS24 as a landmark after ASCT in patients with RR DLBCL, we identified patients with RR DLBCL after frontline R-CHOP or R-CHOP-like IC who underwent salvage therapy and ASCT at Mayo Clinic between July 2000 and December 2017 and University of Iowa between April 2003 and April 2020 from institutional lymphoma and transplantation databases. Clinical characteristics, treatment information, and outcome data were abstracted. PFS, OS, and post-ASCT relapse survival (PRS) were analyzed using Kaplan-Meier method, and cumulative incidences of relapse versus nonrelapse mortality and different causes of death were compared accounting for competing events. A total of 437 patients were identified. Median age at ASCT was 61 years (range 19-78), and 280 (64%) were male. After a median post-ASCT follow-up of 8.0 years (95% confidence interval [CI], 7.2-8.7), 215 patients had a relapse (or disease progression), 180 within 2 years and 35 after 2 years. For the entire cohort, the post-ASCT relapse rate was much higher than the nonrelapse mortality rate (48.1% versus 9.1% at 5 years). Median PFS and OS after ASCT was 2.7 and 5.4 years, respectively. Lymphoma was the primary cause of death after ASCT. In contrast, for patients who had achieved PFS24 (n = 220), rates of post-PFS24 relapse and nonrelapse mortality were similar (14.8% and 12.3% at 5 years). Median PFS and OS after achieving PFS24 was 10.0 and 11.5 years, respectively. Lymphoma-related and -unrelated death rates were similar after achieving PFS24. For all patients who had a post-ASCT relapse, median PRS was 0.7 (95% CI, 0.5-0.9) year, and late relapse (>2 versus ≤2 years after ASCT) was associated with better PRS (median 2.3 [1.7-4.8] versus 0.5 [0.3-0.7] years, P< .001). The study establishes PFS24 as an important landmark associated with post-ASCT outcomes in patients with RR DLBCL after frontline IC.

Incidence of thrombosis in relapsed/refractory B-cell lymphoma treated with axicabtagene ciloleucel: Mayo Clinic experience.

Chimeric antigen receptor (CAR) T-cell therapy is effective in relapsed/refractory large B-cell lymphoma and results in a unique toxicity profile, namely cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome. The hyper-inflammatory state associated with these toxicities has been suggested to increase the risk of thrombosis. We conducted a retrospective analysis of patients treated with axicabtagene ciloleucel (axi-cel) to assess the rate of thrombosis with axi-cel therapy from the time of CAR T-cell infusion until the end of hospitalization, when performed in the inpatient setting, or up to day +30 when performed in the outpatient setting. Ninety-two (95%) of 97 patients were hospitalized during axi-cel therapy and 85 (88%) developed CRS. Fifty-five patients (57%) received concurrent anticoagulation (53 as prophylaxis). Patients with prior VTE did not have progression or evidence of new VTE. Only 2 (2.1%) patients developed VTE. These results demonstrate a low-risk for thrombosis in axi-cel recipients.