Pre-treatment peripheral blood immunophenotyping and response to neoadjuvant chemotherapy in operable breast cancer.

BACKGROUND: Tumor immune infiltration and peripheral blood immune signatures have prognostic and predictive value in breast cancer. Whether distinct peripheral blood immune phenotypes are associated with response to neoadjuvant chemotherapy (NAC) remains understudied. METHODS: Peripheral blood mononuclear cells from 126 breast cancer patients enrolled in a prospective clinical trial (NCT02022202) were analyzed using Cytometry by time-of-flight with a panel of 29 immune cell surface protein markers. Kruskal-Wallis tests or Wilcoxon rank-sum tests were used to evaluate differences in immune cell subpopulations according to breast cancer subtype and response to NAC. RESULTS: There were 122 evaluable samples: 47 (38.5%) from patients with hormone receptor-positive, 39 (32%) triple-negative (TNBC), and 36 (29.5%) HER2-positive breast cancer. The relative abundances of pre-treatment peripheral blood T, B, myeloid, NK, and unclassified cells did not differ according to breast cancer subtype. In TNBC, higher pre-treatment myeloid cells were associated with lower pathologic complete response (pCR) rates. In hormone receptor-positive breast cancer, lower pre-treatment CD8 + naïve and CD4 + effector memory cells re-expressing CD45RA (TEMRA) T cells were associated with more extensive residual disease after NAC. In HER2 + breast cancer, the peripheral blood immune phenotype did not differ according to NAC response. CONCLUSIONS: Pre-treatment peripheral blood immune cell populations (myeloid in TNBC; CD8 + naïve T cells and CD4 + TEMRA cells in luminal breast cancer) were associated with response to NAC in early-stage TNBC and hormone receptor-positive breast cancers, but not in HER2 + breast cancer. TRIAL REGISTRATION: NCT02022202 . Registered 20 December 2013.

Serial Evaluation of Preimmunization Antibody Titers in Lymphoma Patients Receiving Chimeric Antigen Receptor T Cell Therapy.

Antibody titers and the potential need for immunization have not been formally studied in recipients of chimeric antigen receptor T cell therapy (CAR-T). Prior studies have shown that CD19-targeted CAR-T can induce persistent B cell aplasia but preserve plasma cells for humoral response. Aiming to assess the immune repertoire and antibody titer status of CAR-T recipients, we conducted a retrospective study of immune cell recovery and antibody titers to vaccines in anti-CD19 CAR-T recipients at Mayo Clinic, Rochester. In our cohort of 95 CAR-T recipients, almost one-half had low CD4 T and B cell counts prior to CAR-T that remained persistently low post-CAR-T. Prior to CAR-T, the seronegative rate was lowest for tetanus and highest for pneumococcus irrespective of prior transplantation status (within 2 years of CAR-T). At 3 months post-CAR-T, overall seronegativity rates were similar to pre-CAR-T rates for the prior transplantation and no prior transplantation groups. For patients who received IVIG, loss of seropositivity was seen for hepatitis A (1 of 7; 14%). No seroconversion was noted for pneumococcus. For patients who did not receive IVIG, loss of seropositivity was seen for pneumococcus (2 of 5; 40%) and hepatitis A (1 of 4; 25%). CAR-T recipients commonly experience T cell and B cell lymphopenia and might not have adequate antibody titers against vaccine-preventable diseases despite IVIG supplementation. Loss of antibody titers post-CAR-T is possible, highlighting the need for revaccination. Additional studies with long-term follow-up are needed to inform the optimal timing of immunization post-CAR-T.

Day 100 Natural Killer Cell/CD14+HLA-DRDIM ratio and survival in lymphoma post-autologous peripheral blood hematopoietic stem cell transplantation.

INTRODUCTION: The infusion of autograft Natural Killer Cells (NKC)/CD14+ HLA-DRDIM ratio is a predictor of survival in lymphoma patients undergoing autologous peripheral blood hematopoietic stem cell transplantation (APBHSCT). This study evaluated if the Day 100 NKC/CD14+ HLA-DRDIM ratio still functions as a prognostic immune-biomarker. METHODS: This was a retrospective, single-institution, cohort analysis including 107 patients in this study that had clinical assessment at Day 100 post-APBHSCT from our prior phase III trial. We evaluated the prognostic ability of the Day 100 NKC/CD14+ HLA-DRDIM ratio to predict overall survival (OS) and progression-free survival (PFS) using Cox regression model for outcome analysis and survival by Kaplan-Meier method. RESULTS: The median follow-up from day 100 was 94.7 months (range 4.83-158.1 months) for the entire cohort. Patients with a Day 100 NKC/CD14+ HLA-DRDIM ratio ≥1.67 experienced better OS and PFS versus those with a Day 100 NKC/CD14+ HLA-DRDIM ratio <1.67: median OS was not reached versus 49.7 months, the 5-year OS rates were 91% (95% CI, 81%-96%) versus 40% (95% CI, 27%-55%), p < .0001, respectively; and median PFS was not reached versus 23.5 months, the 5-year PFS rates were 66% (95% CI, 55%-81%) versus 21% (95% CI, 15%-40%), p < .0001, respectively. Day 100 NKC/CD14+ HLA-DRDIM ratio was an independent predictor for OS and PFS in the multivariate analysis. CONCLUSIONS: Day 100 NKC/CD14+ HLA-DRDIM ratio is a prognostic immune-biomarker in lymphoma patients post- APBHSCT.

T-cell phenotype including CD57+ T follicular helper cells in the tumor microenvironment correlate with a poor outcome in follicular lymphoma.

T-lymphocytes are prevalent in the tumor microenvironment of follicular lymphoma (FL). However, the phenotype of T-cells may vary, and the prevalence of certain T-cell subsets may influence tumor biology and patient survival. We therefore analyzed a cohort of 82 FL patients using CyTOF to determine whether specific T-cell phenotypes were associated with distinct tumor microenvironments and patient outcome. We identified four immune subgroups with differing T-cell phenotypes and the prevalence of certain T-cell subsets was associated with patient survival. Patients with increased T cells with early differentiation stage tended to have a significantly better survival than patients with increased T-cells of late differentiation stage. Specifically, CD57+ TFH cells, with a late-stage differentiation phenotype, were significantly more abundant in FL patients who had early disease progression and therefore correlated with an inferior survival. Single cell analysis (CITE-seq) revealed that CD57+ TFH cells exhibited a substantially different transcriptome from CD57- TFH cells with upregulation of inflammatory pathways, evidence of immune exhaustion and susceptibility to apoptosis. Taken together, our results show that different tumor microenvironments among FL patients are associated with variable T-cell phenotypes and an increased prevalence of CD57+ TFH cells is associated with poor patient survival.

Consolidative radiotherapy for residual fluorodeoxyglucose activity on day +30 post CAR T-cell therapy in non-Hodgkin lymphoma.

Majority of non-Hodgkin lymphoma (NHL) patients who achieve partial response (PR) or stable disease (SD) to CAR T-cell therapy (CAR T) on day +30 progress and only 30% achieve spontaneous complete response (CR). This study is the first to evaluate the role of consolidative radiotherapy (cRT) for residual fluorodeoxyglucose (FDG) activity on day +30 post- CAR T in NHL. We retrospectively reviewed 61 patients with NHL who received CAR T and achieved PR or SD on day +30. Progression-free survival (PFS), overall survival (OS), and local relapse-free survival (LRFS) were assessed from CAR T infusion. cRT was defined as comprehensive - treated all FDG-avid sites - or focal. Following day +30 positron emission tomography scan, 45 patients were observed and 16 received cRT. Fifteen (33%) observed patients achieved spontaneous CR, and 27 (60%) progressed with all relapses involving initial sites of residual FDG activity. Ten (63%) cRT patients achieved CR, and four (25%) progressed with no relapses in the irradiated sites. The 2-year LRFS was 100% in the cRT sites and 31% in the observed sites (P<0.001). The 2-year PFS was 73% and 37% (P=0.025) and the 2-year OS was 78% and 43% (P=0.12) in the cRT and observation groups, respectively. Patients receiving comprehensive cRT (n=13) had superior 2- year PFS (83% vs. 37%; P=0.008) and 2-year OS (86% vs. 43%; P=0.047) compared to observed or focal cRT patients (n=48). NHL patients with residual FDG activity following CAR T are at high risk of local progression. cRT for residual FDG activity on day +30 post-CAR T appears to alter the pattern of relapse and improve LRFS and PFS.

Response to COVID-19 Vaccination Post-CAR T Therapy in Patients With Non-Hodgkin Lymphoma and Multiple Myeloma.

COVID-19 adversely affects individuals with cancer. Several studies have found that seroconversion rates among patients with hematologic malignancies are suboptimal when compared to patients without cancer. Patients with non-Hodgkin lymphoma (NHL) and multiple myeloma (MM) are immunocompromised due to impaired humoral and cellular immunity in addition to prescribed immunosuppressive therapy. Chimeric antigen receptor T-cell (CAR T) therapy is now widely used for NHL and MM, but little is known about seroconversion rates after COVID-19 vaccination among these populations. We evaluated SARS-CoV-2 spike-binding IgG antibody levels following COVID-19 vaccination among NHL and MM CAR T therapy recipients. Out of 104 CAR T infusions, 19 patients developed known COVID-19 infection post-CAR T. We tested 17 patients that received CAR T for antibody spike titers post COVID-19 vaccination, only 29 % (n = 5) were able to mount a clinically relevant antibody response (>250 IU/mL).

Cytokines and Immune Cell Phenotype in Acute Kidney Injury Associated With Immune Checkpoint Inhibitors.

Introduction: Immune checkpoint inhibitors (ICIs) induce impressive antitumor responses but may lead to acute kidney injury (AKI) associated with ICI therapy (AKI-ICI). Biomarkers distinguishing AKI-ICI from AKI because of other causes (AKI-other) are currently lacking. Because ICIs block immunoregulatory pathways, we hypothesized that biomarkers related to immune cell dysregulation, including tumor necrosis factor alpha (TNF-α) and other markers of B and T cell activation in the systemic circulation and kidney tissue, may aid with the diagnosis of AKI-ICI. Methods: This is a prospective study consisting of 24 participants who presented with AKI during ICI therapy, adjudicated to either have AKI-ICI (n = 14) or AKI-other (n = 10). We compared markers of kidney inflammation and injury (neutrophil gelatinase-associated lipocalin, kidney injury molecule-1) as well as plasma and urine levels of T cell-associated cytokines (TNF-α, interferon-γ, interleukin (IL)-2, IL-4, IL-6, IL-8, IL-9, and IL-10) between groups. We also compared T-cell responses in the systemic circulation and in kidney tissue across groups, using mass cytometry systems. Results: We observed increase in several specific immune cells, including CD4 memory, T helper cells, and dendritic cells in the kidney tissue, as well as in the urine cytokines IL-2, IL-10, and TNF-α, in patients who developed AKI-ICI compared to patients with AKI-other (P < 0.05 for all). The discriminatory ability of TNF-α on AKI cause was strong (area under the curve = 0.814, 95% confidence interval: 0.623-1.00. The CD4+ T cells with memory phenotype formed the dominant subset. Conclusion: These results suggest that specific T-cell responses and their respective cytokines may be indicative of AKI associated with ICI therapy and may help to differentiate AKI-ICI from AKI-other. Urine TNF-α is a promising biomarker for AKI-ICI, which is most often caused by acute interstitial nephritis (AIN), and TNF-α pathway may serve as a potential target for therapeutic intervention.

Outcomes of Older Adults with Non-Hodgkin Lymphoma Undergoing Autologous Stem Cell Transplantation: A Mayo Clinic Cohort Analysis.

Autologous stem cell transplantation (ASCT) is an important treatment that can offer a cure for patients with lymphoma. However, advanced age is an important factor that determines eligibility and outcomes after ASCT. Over the past decade, attributed to improved supportive care, ASCT for older patients has become more feasible. In this study, we report the single-center outcomes of older patients with lymphoma undergoing ASCT at Mayo Clinic Rochester to highlight its interval improvement over time and to help redefine the implications of ASCT in the chimeric antigen receptor T cell therapy era. This single-center retrospective study evaluated the characteristics and outcomes of older patients with lymphoma who underwent ASCT between 2000 and 2021. We report various relevant transplantation-related outcomes, including progression-free survival, overall survival (OS), relapse incidence, and nonrelapse mortality (NRM) in older patients with various lymphoma histologic subtypes. The main outcome was NRM, defined as the time from ASCT to non-lymphoma-related death, with relapse as a competing event. Of 492 patients age ≥65 years were analyzed. The median age at ASCT was 68.8 years. The most common indication for ASCT was diffuse large B cell lymphoma, accounting for 59.3% of cases. In multivariate analyses, patients undergoing ASCT in 2009 to 2021, an Eastern Cooperative Oncology Group Performance Status of 0, and low Hematopoietic Cell Transplantation Comorbidity Index (HCT-CI) (0 to 3) had a significantly lower NRM. Factors associated with OS included age, lactate dehydrogenase level, and HCT-CI. The 1-year NRM in older patients was low at 6.0%, in concordance with previous reports. Age should not be the sole factor determining a patient's ASCT eligibility. With the proper patient selection, ASCT remains a reasonable option for older patients with lymphoma.

Don't Put the CART Before the Horse: The Role of Radiation Therapy in Peri-CAR T-cell Therapy for Aggressive B-cell Non-Hodgkin Lymphoma.

PURPOSE: The optimal approach to incorporate radiation therapy (RT) in conjunction with chimeric antigen receptor (CAR) T-cell therapy (CART) for relapsed/refractory (r/r) B-cell non-Hodgkin lymphoma (bNHL) remains unclear. This study documented the RT local control rate among patients who received bridging radiation therapy (BRT) before CART and compares it with those who received salvage radiation therapy (SRT) after CART. This article further reports on a promising way to use SRT for post-CART disease and identifies predictors for RT in-field recurrence. METHODS AND MATERIALS: We retrospectively reviewed 83 patients with r/r bNHL who received CART and RT, either as BRT pre-CART infusion (n = 35) or as SRT post-CART infusion (n = 48), between 2018 and 2021. RT was defined as comprehensive (compRT; ie, treated all sites of active disease) or focal (focRT). Limited disease was defined as disease amenable to compRT, involving <5 active disease sites. RESULTS: At time of RT, patients who received BRT before CART had bulkier disease sites (median diameter, 8.7 vs 5.5 cm; P = .01) and were treated to significantly lower doses (median equivalent 2-Gy dose, 23.3 vs 34.5 Gy; P = .002), compared with SRT post-CART. Among 124 total irradiated sites identified, 8 of 59 (13%) bridged sites and 21 of 65 (32%) salvaged sites experienced in-field recurrence, translating to 1-year local control rates (LC) of 84% and 62%, respectively (P = .009). Patients with limited post-CART disease (n = 37) who received compSRT (n = 26) had better overall survival (51% vs 12%; P = .028), freedom from subsequent progression (31% vs 0%; P < .001), and freedom from subsequent event (19% vs 0%; P = .011) compared with patients with limited disease who received focSRT (n = 11). CONCLUSIONS: BRT followed by CART appears to be associated with improved LC compared with SRT in r/r bNHL. Nonetheless, SRT offers a promising salvage intervention for limited (<5 sites) relapsed post-CART disease if given comprehensively.

Central nervous system involvement by mantle cell lymphoma.

Involvement of the central nervous system (CNS) is a rare complication of mantle cell lymphoma (MCL) with limited treatment options. We report the outcomes of 36 patients with CNS involvement compared to 72 matched control MCL patients without CNS involvement. Four patients (11%) with CNS MCL were diagnosed with CNS involvement at time of MCL diagnosis. Median OS from MCL diagnosis was 50.3 months (95% CI: 22.8-79.6) for the CNS MCL group compared to 97.1 months (95% CI: 82.8-NR; p= <0.001) for the control group. Median OS from CNS involvement was 4.7 months (95% CI: 2.3-6.7). CNS involvement by MCL has dismal outcomes as evident by a short median OS and PFS after CNS involvement. Advanced stage, blastoid variant, elevated LDH, and elevated Ki67 at MCL diagnosis were features more commonly seen in the CNS MCL cohort.

High-Dose Methotrexate in Patients With Lymphoma: Predictors of a Complicated Course.

PURPOSE: High-dose methotrexate (HDMTX; > 500 mg/m2) is an important component of lymphoma therapy. Serum MTX monitoring at 48 hours is the standard approach to identify those at increased risk of developing MTX toxicity. Our aim was to characterize the incidence of complications and their association with MTX levels. METHODS: A retrospective review of our institutional electronic medical record was conducted to identify patients with lymphoma who received HDMTX between January 1, 2002, and December 31, 2018. We characterized the incidence of acute kidney injury (AKI), intensive care unit (ICU) admission, length of hospital stay (LOS), and 30-day mortality across 48-hour MTX levels. To establish an association between 48-hour MTX levels and the complications listed, we performed chi-square analysis for dichotomous variables and Kruskal-Wallis for nonparametric data. Receiver operator characteristic curve analysis was performed to identify the MTX level where AKI grade ≥ 2 was more likely. Multivariate logistic regression analysis was performed to identify risk factors for this MTX level. RESULTS: We identified 642 patients with 2,804 cycles of HDMTX. The incidence of AKI was 19.1% with AKI grade ≥ 2 making up 21% of cases. Rates of AKI, ICU admission, and 30-day mortality are associated with elevated 48-hour MTX levels. There was a significant increase in median LOS with elevated MTX levels (P < .001). Receiver operator characteristic curve analysis for AKI grade ≥ 2 demonstrated a 48-hour MTX level threshold of 1.28 µmol/L. Multivariate logistic regression analysis revealed age, male sex, elevated body surface area, higher MTX dose, monotherapy, and first cycle as independent factors. CONCLUSION: Elevated MTX levels are associated with a significant increased rate of AKI, ICU admission, prolonged LOS, and 30-day mortality. Elevated 48-hour MTX levels, particularly > 1.28 µmol/L, should alert clinicians for complications and to initiate measures to reduce MTX levels.

Incidence and Risk Factors for Acute Kidney Injury After Chimeric Antigen Receptor T-Cell Therapy.

OBJECTIVE: To evaluate the association of baseline and postinfusion patient characteristics with acute kidney injury (AKI) in the month after chimeric antigen receptor T-cell (CAR-T) therapy. METHODS: We retrospectively reviewed records of 83 patients with non-Hodgkin lymphoma undergoing CAR-T therapy (axicabtagene ciloleucel) between June 2016 and November 2020. Patients were followed up to 1 month after treatment. Post-CAR-T AKI was defined as a more than 1.5-fold increase in serum creatinine concentration from baseline (on the day of CAR-T infusion) at any time up to 1 month after CAR-T therapy. RESULTS: Of 83 patients, 14 (17%) developed AKI during follow-up. At 1 month after CAR-T infusion, 10 of 14 (71%) AKI events had resolved. Lower baseline estimated glomerular filtration rate, use of intravenous contrast material, tumor lysis prophylaxis, higher peak uric acid and creatine kinase levels during follow-up, and change in lactate dehydrogenase from baseline to peak level within 1 month after initiation of CAR-T therapy were significantly associated with AKI incidence during follow-up. Incidence of AKI was also higher in patients who received higher doses of corticosteroids and tocilizumab. CONCLUSION: Acute kidney injury occurred in approximately 1 in 6 patients who received axicabtagene ciloleucel for non-Hodgkin lymphoma. Patients with high tumor burden receiving higher total doses of corticosteroids or tocilizumab should be closely monitored for development of AKI. Lower baseline kidney function at CAR-T initiation, exposure to contrast material, and progressive increase in levels of tumor lysis markers (uric acid, lactate dehydrogenase, creatine kinase) after CAR-T infusion may predict risk of AKI during the 1 month after infusion.

Long-term outcome of immunologic autograft engineering.

Our phase III trial reported that autograft-absolute lymphocyte count (A-ALC) improved survival post-autologous peripheral blood hematopoietic stem cell transplantation (APBHSCT) for a short-term follow-up of 2 years. We evaluated retrospectively in our phase III trial patients that the A-ALC still confers survival benefit with a longer follow-up. With a median follow-up of 127.6 months, patients infused with an A-ALC ≥ 0.5 × 109 cells/kg experienced better overall survival (HR = 0.392, 95% confidence of interval [CI]: 0.224-0.687, p < 0.001) and progression-free survival (HR = 0.413, 95% CI: 0.253-0.677), p < 0.0004). This study supports that A-ALC provides long-term survival benefit post APBHSCT.

Causes of death in low-grade B-cell lymphomas in the rituximab era: a prospective cohort study.

Low-grade B-cell lymphomas other than follicular and small lymphocytic lymphoma (LGBCL) account for 10% of all B-cell non-Hodgkin lymphomas. Despite improvements in survival outcomes for these patients, little is known about cause of death (COD) in the rituximab era. For a better understanding, we studied 822 newly diagnosed patients with marginal zone, lymphoplasmacytic, and unclassifiable low-grade B-cell lymphoma prospectively enrolled in the University of Iowa/Mayo Clinic Specialized Program of Research Excellence Molecular Epidemiology Resource from 2002 to 2015. COD was assigned based on medical record review using a standard protocol. At a median follow-up of 107 months, 219 (27%) patients had died. The incidence of lymphoma-related deaths when pooling across subtypes was lower than non-lymphoma-related deaths (10-year incidence, 8.0%; 95% confidence interval [CI]: 6.2-10.4 vs 13.6%; 95% CI: 11.2-16.6). The incidence of lymphoma-related deaths varied by subtype, ranging from 3.7% at 10 years in extranodal marginal zone lymphoma to 19.3% in lymphoplasmacytic lymphoma/Waldenström macroglobulinemia. Patients with early progression or retreatment events, defined using event-free survival at 24 months from diagnosis, had significantly higher likelihood of lymphoma-related death compared with patients without early events (10-year estimate: 19.1% vs 5.1%, respectively; P < .001), whereas the rates for non-lymphoma-related death were comparable in patients with or without early events (10-year estimates: 11.0% vs 15.3%, respectively). In conclusion, the most common COD in LGBCLs in the first decade after diagnosis was for causes other than lymphoma. Progression or retreatment within the first 2 years of diagnosis was a strong predictor for risk of lymphoma-related death.

Impact of autograft-absolute lymphocyte count on survival in double/triple hit lymphomas post-autologous stem cell transplantation.

The autograft absolute lymphocyte count (A-ALC) ≥0.5 × 109 cells/kg is a survival prognostic factor for lymphoma patients undergoing autologous peripheral blood hematopoietic stem cell transplantation (APBHSCT). However, the A-ALC has not be tested as prognostic factor against double hit/triple hit lymphomas (DHL/THL). Thus, we set up to investigate if A-ALC is a prognostic factor for overall survival (OS) and progression-free survival (PFS) for DHL/THL post-APBHSCT. From January 2012 until December 2020, we identified 77 DHL/THL patients treated with APBHSCT. All patients required to have the diagnosis of DHL/THL by FISH for rearrangements of MYC, BCL2, and BCL6. With a median follow-up of 20.4 months (range, 0.4-94.5 months), DHL/THL patients infused with A-ALC ≥0.5 x 109 cells/kg experienced superior OS (HR = 0.251, 95%CI 0.117-0.539, p < 0.0004) and PFS (HR = 0.347, 95%CI 0.160-0.753, p < 0.007). Multivariate analysis showed that A-ALC was an independent predictor for OS (HR =0.119, 95%CI 0.030-0.473, p < 0.003) and PFS (HR = 0.400, 95%CI 0.189-0.850, p < 0.02). Our study showed that A-ALC is a prognostic factor for survival in DHL/THL. Our current practice for lymphoma patients is to collect enough stem cell but also A-ALC to improve clinical outcomes post-APBHSCT.

Clinical activity of single-dose systemic oncolytic VSV virotherapy in patients with relapsed refractory T-cell lymphoma.

Clinical success with intravenous (IV) oncolytic virotherapy (OV) has to-date been anecdotal. We conducted a phase 1 clinical trial of systemic OV and investigated the mechanisms of action in responding patients. A single IV dose of vesicular stomatitis virus (VSV) interferon-ß (IFN-ß) with sodium iodide symporter (NIS) was administered to patients with relapsed/refractory hematologic malignancies to determine safety and efficacy across 4 dose levels (DLs). Correlative studies were undertaken to evaluate viremia, virus shedding, virus replication, and immune responses. Fifteen patients received VSV-IFNß-NIS. Three patients were treated at DL1 through DL3 (0.05, 0.17, and 0.5 × 1011 TCID50), and 6 were treated at DL4 (1.7 × 1011 TCID50) with no dose-limiting toxicities. Three of 7 patients with T-cell lymphoma (TCL) had responses: a 3-month partial response (PR) at DL2, a 6-month PR, and a complete response (CR) ongoing at 20 months at DL4. Viremia peaked at the end of infusion, g was detected. Plasma IFN-ß, a biomarker of VSV-IFNß-NIS replication, peaked between 4 hours and 48 hours after infusion. The patient with CR had robust viral replication with increased plasma cell-free DNA, high peak IFN-ß of 18 213 pg/mL, a strong anti-VSV neutralizing antibody response, and increased numbers of tumor reactive T-cells. VSV-IFNß-NIS as a single agent was effective in patients with TCL, resulting in durable disease remissions in heavily pretreated patients. Correlative analyses suggest that responses may be due to a combination of direct oncolytic tumor destruction and immune-mediated tumor control. This trial is registered at www.clinicaltrials.gov as #NCT03017820.