Baseline Serum Inflammatory Proteins Predict Poor CAR T Outcomes in Diffuse Large B-cell Lymphoma

A subset of patients with diffuse large B-cell lymphoma (DLBCL) treated with CD19 chimeric antigen receptor (CAR) T-cell therapy have poor clinical outcomes. We report serum proteins associated with severe immune-mediated toxicities and inferior clinical responses in 146 patients with DLBCL treated with axicabtagene ciloleucel. We develop a simple stratification based on pre-lymphodepletion C reactive protein (CRP) and ferritin to classify patients into low-, intermediate-, and high-risk groups. We observe that patients in the high-risk category were more likely to develop grade ≥3 toxicities and had inferior overall and progression-free survival. We sought to validate our findings with two independent international cohorts demonstrating that patients classified as low-risk have excellent efficacy and safety outcomes. Based on routine and readily available laboratory tests that can be obtained prior to lymphodepleting chemotherapy, this simple risk stratification can inform patient selection for CAR T-cell therapy.

SIGNIFICANCE

CAR T-cell therapy has changed the treatment paradigm for patients with relapsed/refractory hematologic malignancies. Despite encouraging efficacy, a subset of patients have poor clinical outcomes. We show that a simple clinically applicable model using pre-lymphodepletion CRP and ferritin can identify patients at high risk of poor outcomes. This article is featured in Selected Articles from This Issue, p. 80.

Transplantation Outcomes of Myelofibrosis with Busulfan and Fludarabine Myeloablative Conditioning

Outcomes of myelofibrosis (MF) with allogeneic stem cell transplantation (allo-SCT) have improved over the past decade, related in part to advances in supportive treatments and conditioning regimens. Several factors are known to predict transplantation outcomes. However, most studies lack homogeneity in conditioning regimens used, limiting their ability to assess prognostic factors on transplantation outcomes. We aimed to identify the risk factors that predict transplantation outcomes in patients with MF who underwent matched or mismatched allo-SCT using a uniform myeloablative conditioning regimen consisting of busulfan and fludarabine with tacrolimus and methotrexate-based graft-versus-host disease prophylaxis. This single-center study included patients with MF who underwent allo-SCT with a matched unrelated donor (MUD), matched related donor (MRD), or mismatched unrelated donor (MMUD) and received busulfan and fludarabine conditioning with methotrexate/tacrolimus-based GVHD prophylaxis. Sixty-five patients with MF met the study criteria and were included in our analysis. At a median follow-up of 35.6 months, the 3-year cumulative incidence of relapse (CIR), nonrelapse mortality (NRM), and overall survival (OS) for all study patients were 27%, 20%, and 65%, respectively. In a multivariable analysis for CIR, prior use of JAK inhibitors was significantly associated with a decreased risk of relapse (hazard ratio [HR], .33; 95% confidence interval [CI], .11 to .99; P = .048). For NRM, Hematopoietic Cell Transplantation Comorbidity Index (≥3 versus <3; HR, 10.09; 95% CI, 2.09 to 48.76; P = .004) and donor type (MUD versus MRD: HR, 5.38; 95% CI, 1.14 to 25.30; P = .033; MMUD versus MRD: HR, 10.73; 95% CI, 1.05 to 109.4; P = .045) were associated with an increased risk of mortality. Likewise for OS, HCT-CI (≥3 versus <3; HR, 3.31; 95% CI, 1.22 to 8.99; P = .019) and donor type (MMUD versus MRD: HR, 5.20; 95% CI, 1.35 to 19.98; P = .016) were significantly associated with inferior survival. Longer time from diagnosis to allo-SCT seemed to confer worse survival, but the difference did not reach statistical significance (>12 months versus ≤12 months: NRM: HR, 7.20; 95% CI, .96 to 53.94; P = .055; OS: HR, 2.60; 95% CI, .95 to 7.14; P = .06). In a homogenous cohort of MF patients uniformly treated with busulfan/fludarabine myeloablative conditioning and methotrexate-based GVHD prophylaxis, we show that donor choice and HCT-CI are the 2 strongest predictors for improved survival after allo-SCT.

A non-antibiotic-disrupted gut microbiome is associated with clinical responses to CD19-CAR-T cell cancer immunotherapy

Increasing evidence suggests that the gut microbiome may modulate the efficacy of cancer immunotherapy. In a B cell lymphoma patient cohort from five centers in Germany and the United States (Germany, n = 66; United States, n = 106; total, n = 172), we demonstrate that wide-spectrum antibiotics treatment ('high-risk antibiotics') prior to CD19-targeted chimeric antigen receptor (CAR)-T cell therapy is associated with adverse outcomes, but this effect is likely to be confounded by an increased pretreatment tumor burden and systemic inflammation in patients pretreated with high-risk antibiotics. To resolve this confounding effect and gain insights into antibiotics-masked microbiome signals impacting CAR-T efficacy, we focused on the high-risk antibiotics non-exposed patient population. Indeed, in these patients, significant correlations were noted between pre-CAR-T infusion Bifidobacterium longum and microbiome-encoded peptidoglycan biosynthesis, and CAR-T treatment-associated 6-month survival or lymphoma progression. Furthermore, predictive pre-CAR-T treatment microbiome-based machine learning algorithms trained on the high-risk antibiotics non-exposed German cohort and validated by the respective US cohort robustly segregated long-term responders from non-responders. Bacteroides, Ruminococcus, Eubacterium and Akkermansia were most important in determining CAR-T responsiveness, with Akkermansia also being associated with pre-infusion peripheral T cell levels in these patients. Collectively, we identify conserved microbiome features across clinical and geographical variations, which may enable cross-cohort microbiome-based predictions of outcomes in CAR-T cell immunotherapy.

A polyamine-centric, blood-based metabolite panel predictive of poor response to CAR-T cell therapy in large B cell lymphoma

Anti-CD19 chimeric antigen receptor (CAR) T cell therapy for relapsed or refractory (r/r) large B cell lymphoma (LBCL) results in durable response in only a subset of patients. MYC overexpression in LBCL tumors is associated with poor response to treatment. We tested whether an MYC-driven polyamine signature, as a liquid biopsy, is predictive of response to anti-CD19 CAR-T therapy in patients with r/r LBCL. Elevated plasma acetylated polyamines were associated with non-durable response. Concordantly, increased expression of spermidine synthase, a key enzyme that regulates levels of acetylated spermidine, was prognostic for survival in r/r LBCL. A broad metabolite screen identified additional markers that resulted in a 6-marker panel (6MetP) consisting of acetylspermidine, diacetylspermidine, and lysophospholipids, which was validated in an independent set from another institution as predictive of non-durable response to CAR-T therapy. A polyamine centric metabolomics liquid biopsy panel has predictive value for response to CAR-T therapy in r/r LBCL.

Clonal Hematopoiesis Is Associated with Increased Risk of Severe Neurotoxicity in Axicabtagene Ciloleucel Therapy of Large B-Cell Lymphoma

To explore the role of clonal hematopoiesis (CH) in chimeric antigen receptor (CAR) T-cell therapy outcomes, we performed targeted deep sequencing on buffy coats collected during the 21 days before lymphodepleting chemotherapy from 114 large B-cell lymphoma patients treated with anti-CD19 CAR T cells. We detected CH in 42 (36.8%) pretreatment samples, most frequently in PPM1D (19/114) and TP53 (13/114) genes. Grade ≥3 immune effector cell-associated neurotoxicity syndrome (ICANS) incidence was higher in CH-positive patients than CH-negative patients (45.2% vs. 25.0%, P = 0.038). Higher toxicities with CH were primarily associated with DNMT3A, TET2, and ASXL1 genes (DTA mutations). Grade ≥3 ICANS (58.9% vs. 25%, P = 0.02) and ≥3 cytokine release syndrome (17.7% vs. 4.2%, P = 0.08) incidences were higher in DTA-positive than in CH-negative patients. The estimated 24-month cumulative incidence of therapy-related myeloid neoplasms after CAR T-cell therapy was higher in CH-positive than CH-negative patients [19% (95% CI, 5.5-38.7) vs. 4.2% (95% CI, 0.3-18.4), P = 0.028].

SIGNIFICANCE

Our study reveals that CH mutations, especially those associated with inflammation (DNMT3A, TET2, and ASXL1), are associated with severe-grade neurotoxicities in lymphoma patients receiving anti-CD19 CAR T-cell therapy. Further studies to investigate the mechanisms and interventions to improve toxicities in the context of CH are warranted. See related content by Uslu and June, p. 382. This article is highlighted in the In This Issue feature, p. 369.

Real-world long-term outcomes in multiple myeloma with VRD induction, Mel200-conditioned auto-HCT, and lenalidomide maintenance

Standard-of-care for newly-diagnosed, autologous hematopoietic stem cell transplantation (auto-HCT)-eligible, multiple myeloma (MM) patients includes bortezomib, lenalidomide, and dexamethasone (VRD) induction followed by melphalan 200 mg/m² (Mel200)-conditioned auto-HCT and lenalidomide maintenance. We completed a retrospective case series assessing outcomes of 187 MM patients who received this regimen at our institution. The 100-day non-relapse mortality incidence was zero. Before auto-HCT, 9.6 and 52.9% of patients achieved a complete response (CR) or ≥ very good partial response (VGPR), respectively. At day-100 post-transplant, 29.4 and 74.9% had achieved a CR/stringent-CR (sCR) or ≥ VGPR, respectively. At the last evaluation, 57.2% of patients had CR/sCR and 87.1% had ≥ VGPR. Median follow-up, progression-free survival (PFS), and overall survival (OS) were 63.2, 50, and 101.7 months, respectively. The 5-year PFS and OS were 43.1 and 79%. High-risk cytogenetics was associated with worse outcomes. This study illustrates that VRD induction, Mel200-conditioned auto-HCT, and lenalidomide maintenance are associated with good outcomes in MM.

Chimeric Antigen Receptor T-Cells in B-Acute Lymphoblastic Leukemia: State of the Art and Future Directions

Use of adoptive T-cell therapy modified with chimeric antigen receptor (CAR-T) has revolutionized treatment of patients with relapsed/refractory (r/r) B-cell acute lymphoblastic leukemia (B-ALL). CAR-T cells directed against CD19 antigen have produced response rates as high as 90% in clinical trials for r/r B-ALL. Despite high rates of complete remissions, the durability of responses has been sub-optimal with frequent relapses, especially in adult B-ALL population. Systemic toxicities from CAR-T therapy and standardization of toxicities grading and management is another major hurdle in the development of CAR-T field. In this review, we discuss the latest evidence of CAR-T therapy in B-ALL, potential mechanisms of relapse and barriers to CAR-T cell therapy in B-ALL. We also debate the role of allogeneic hematopoietic stem cell transplant (allo-HCT) post CAR-T therapy.

Impact of Donor Type and Melphalan Dose on Allogeneic Transplantation Outcomes for Patients with Lymphoma

We analyzed 186 patients with lymphoma who underwent allogeneic stem cell transplantation (ASCT) with fludarabine-melphalan (FM) conditioning and different types of donors (25 haploidentical [HD], 98 matched unrelated [MUD], and 63 matched related [MRD]) at our institution between September 2009 and January 2018. Patients received fludarabine 160 mg/m² (40 mg/m²/day for 4 days) in combination with 1 dose of melphalan 140 mg/m² (FM140) or 100 mg/m² (FM100). Engraftment was similar among the 3 groups (92%, 89%, and 98%, respectively; P = .7). The 6-month cumulative incidence of grade III-IV acute graft-versus-host disease (GVHD) was 4% in the HD group, 14% in the MUD group, and 8% in the MRD group (P not significant), and the respective 3-year cumulative incidence of chronic GVHD was 5%, 16%, and 26% (P not significant). The respective 3-year nonrelapse mortality and relapse rates were 31%, 32%, and 10% (HD versus MUD, P = .9; HD versus MRD, P = .02) and 15%, 21%, and 39% (HD versus MUD, P = .4; HD versus MRD, P = .04). At 3 years, progression-free survival (PFS) was 59%, 44%, and 46% (P not significant); overall survival (OS) was 52%, 54%, and 67% (P not significant); and GVHD-free, relapse-free survival was 39%, 31%, and 24% (P not significant). No differences in the 3-year PFS (57% versus 43%; P = .3) and OS (64% versus 58%; P = .7) were seen between patients receiving FM100 and those receiving FM140. Our data demonstrate that in patients with lymphoma, ASCT with HD transplants have similar outcomes as ASCT with HLA-matched transplants, and the FM100 conditioning regimen appears to be at least as effective as the FM140 regimen.

Elderly do benefit from induction chemotherapy: High dose mitoxantrone-based ("5 + 1") induction chemotherapy regimen in newly diagnosed acute myeloid leukemia

An intensive "5 + 1" regimen, which included bolus high dose cytarabine (HiDAC) at 3 g/m² once daily over 3 hours on days 1-5 and high dose mitoxantrone (HDM) 80 mg/m² on day 2, was evaluated in 101 consecutively treated newly diagnosed acute myeloid leukemia (AML) patients at a single center since 2009. The median age was 65 (range 18-90) years. The 4 and 8-week mortality in our cohort was 3/101 (2.9%) and 7/99 (7%), respectively. The overall response (complete remission [CR] + CRi) was 76.2% (77/101). The median overall survival (OS) stratified by age group <60, 60-69 and ≥70 years were 56, 31 and 9 months respectively (log-rank, P = 0.02). 51.7% (45/84) of patients with intermediate/adverse risk category proceeded to allogeneic stem cell transplants. Among these 84 patients, the percentage of patients able to proceed to transplant in age groups <60, 60-69, and ≥ 70 years were 75% (18/24), 60.7% (17/28), and 31.2% (10/32), respectively. In conclusion, HDM-based chemotherapy regimen produces high CR rates, is well tolerated and more patients can undergo curative postremission therapy including stem cell transplant.

Rare gene fusion rearrangement SPTNB1-PDGFRB in an atypical myeloproliferative neoplasm

The 2016 revision to the World Health Organization classification of myeloid neoplasms and acute leukemia recognizes a distinct class of myeloid and lymphoid tumors with eosinophilia-related proliferations associated with specific gene rearrangements, one of which involves rearrangements of platelet-derived growth factor receptor B (PDGFRB) gene. We report a case of a rare PDGFRB rearrangement with SPTNB1 (spectrin beta, nonerythrocytic 1) that presented as atypical myeloproliferative neoplasm.