Combined chemosensitivity and chromatin profiling prioritizes drug combinations in CLL.

The Bruton tyrosine kinase (BTK) inhibitor ibrutinib has substantially improved therapeutic options for chronic lymphocytic leukemia (CLL). Although ibrutinib is not curative, it has a profound effect on CLL cells and may create new pharmacologically exploitable vulnerabilities. To identify such vulnerabilities, we developed a systematic approach that combines epigenome profiling (charting the gene-regulatory basis of cell state) with single-cell chemosensitivity profiling (quantifying cell-type-specific drug response) and bioinformatic data integration. By applying our method to a cohort of matched patient samples collected before and during ibrutinib therapy, we identified characteristic ibrutinib-induced changes that provide a starting point for the rational design of ibrutinib combination therapies. Specifically, we observed and validated preferential sensitivity to proteasome, PLK1, and mTOR inhibitors during ibrutinib treatment. More generally, our study establishes a broadly applicable method for investigating treatment-specific vulnerabilities by integrating the complementary perspectives of epigenetic cell states and phenotypic drug responses in primary patient samples.

Aggressive B-cell lymphomas in patients with myelofibrosis receiving JAK1/2 inhibitor therapy.

Inhibition of Janus-kinase 1/2 (JAK1/2) is a mainstay to treat myeloproliferative neoplasms (MPN). Sporadic observations reported the co-incidence of B-cell non-Hodgkin lymphomas during treatment of MPN with JAK1/2 inhibitors. We assessed 626 patients with MPN, including 69 with myelofibrosis receiving JAK1/2 inhibitors for lymphoma development. B-cell lymphomas evolved in 4 (5.8%) of 69 patients receiving JAK1/2 inhibition compared with 2 (0.36%) of 557 with conventional treatment (16-fold increased risk). A similar 15-fold increase was observed in an independent cohort of 929 patients with MPN. Considering primary myelofibrosis only (N = 216), 3 lymphomas were observed in 31 inhibitor-treated patients (9.7%) vs 1 (0.54%) of 185 control patients. Lymphomas were of aggressive B-cell type, extranodal, or leukemic with high MYC expression in the absence of JAK2 V617F or other MPN-associated mutations. Median time from initiation of inhibitor therapy to lymphoma diagnosis was 25 months. Clonal immunoglobulin gene rearrangements were already detected in the bone marrow during myelofibrosis in 16.3% of patients. Lymphomas occurring during JAK1/2 inhibitor treatment were preceded by a preexisting B-cell clone in all 3 patients tested. Sequencing verified clonal identity in 2 patients. The effects of JAK1/2 inhibition were mirrored in Stat1-/- mice: 16 of 24 mice developed a spontaneous myeloid hyperplasia with the concomitant presence of aberrant B cells. Transplantations of bone marrow from diseased mice unmasked the outgrowth of a malignant B-cell clone evolving into aggressive B-cell leukemia-lymphoma. We conclude that JAK/STAT1 pathway inhibition in myelofibrosis is associated with an elevated frequency of aggressive B-cell lymphomas. Detection of a preexisting B-cell clone may identify individuals at risk.

Treatment with brentuximab vedotin plus bendamustine in unselected patients with CD30-positive aggressive lymphomas.

OBJECTIVES: A treatment regimen consisting of bendamustine and brentuximab vedotin (BV) has been described as a highly potent salvage therapy and as an effective induction therapy leading to high response rates before autologous stem cell transplantation (ASCT) in patients with classical Hodgkin lymphoma (cHL). In this retrospective analysis, we aimed to assess this therapy's efficacy in unselected patients with cHL and CD30+ peripheral T-cell lymphoma (PTCL). PATIENTS AND METHODS: Data of 28 patients with cHL and five patients with PTCL treated with a combination of bendamustine and BV at three Austrian tertiary cancer centers were analyzed. RESULTS: In patients with cHL, the ORR was 100% (78.6% CR, 21.4% PR). After 17 months median follow-up, median survival times were not reached; 1-year PFS was 81.9%, and 1-year OS was 95.7%. Thirteen eligible patients (46.4%) successfully underwent planned ASCT after salvage therapy with bendamustine and BV and subsequent high-dose chemotherapy. Three of the five PTCL patients achieved CR, while two did not respond and died during or shortly after therapy. CONCLUSION: A combination of bendamustine and BV is an effective salvage and induction therapy before ASCT in patients with relapsed/refractory cHL. Further research is warranted to evaluate the use in patients with PTCL.

Ultra-early response assessment in lymphoma treatment: [18F]FDG PET/MR captures changes in glucose metabolism and cell density within the first 72 hours of treatment.

PURPOSE: To determine whether, in patients with Hodgkin lymphoma (HL) or non-Hodgkin lymphoma (NHL), [18F]FDG PET/MR can capture treatment effects within the first week after treatment initiation, and whether changes in glucose metabolism and cell density occur simultaneously. METHODS: Patients with histologically proven HL or NHL were included in this prospective IRB-approved study. Patients underwent [18F]FDG PET/MR before, and then 48-72 h after (follow-up 1, FU-1) and 1 week after (FU-2) initiation of the first cycle of their respective standard chemotherapy (for HL) or immunochemotherapy (for NHL). Standardized [18F]FDG uptake values (SUVmax, SUVmean) and apparent diffusion coefficients (ADCmin, ADCmean) based on diffusion-weighted MRI, and metabolic and morphological tumour volumes (MTV, VOL) were assessed at each time-point. Multilevel analyses with an unstructured covariance matrix, and pair-wise post-hoc tests were used to test for significant changes in SUVs, ADCs, MTVs and VOLs between the three time-points. RESULTS: A total of 58 patients (11 with HL and 47 with NHL) with 166 lesions were analysed. Lesion-based mean rates of change in SUVmax, SUVmean, ADCmin, ADCmean, MTV and VOL between baseline and FU-1 were -46.8%, -33.3%, +20.3%, +14%, -46% and -12.8%, respectively, and between baseline and FU-2 were -65.1%, -49%, +50.7%, +32.4%, -61.1% and -24.2%, respectively. These changes were statistically significant (P < 0.01) except for the change in VOL between baseline and FU-1 (P = 0.079). CONCLUSION: In lymphoma patients, [18F]FDG PET/MR can capture treatment-induced changes in glucose metabolism and cell density as early as 48-72 h after treatment initiation.

Overexpression of uridine diphospho glucuronosyltransferase 2B17 in high-risk chronic lymphocytic leukemia.

Uridine diphospho glucuronosyltransferase 2B17 (UGT2B17) glucuronidates androgens and xenobiotics including certain drugs. The UGT2B17 gene shows a remarkable copy number variation (CNV), which predisposes for solid tumors and influences drug response. Here, we identify a yet undescribed UGT2B17 mRNA overexpression in poor-risk chronic lymphocytic leukemia (CLL). In total, 320 CLL patients and 449 healthy donors were analyzed. High (above median) UGT2B17 expression was associated with established CLL poor prognostic factors and resulted in shorter treatment-free and overall survival (hazard ratio ([death] 2.18; 95% CI 1.18-4.01; P = .013). The prognostic impact of mRNA expression was more significant than that of UGT2B17 CNV. UGT2B17 mRNA levels in primary CLL samples directly correlated with functional glucuronidation activity toward androgens and the anticancer drug vorinostat (R > 0.9, P < .001). After treatment with fludarabine containing regimens UGT2B17 was up-regulated particularly in poor responders (P = .030). We observed an exclusive involvement of the 2B17 isoform within the UGT protein family. Gene expression profiling of a stable UGT2B17 knockdown in the CLL cell line MEC-1 demonstrated a significant involvement in key cellular processes. These findings establish a relevant role of UGT2B17 in CLL with functional consequences and potential therapeutic implications.

Rituximab maintenance for patients with aggressive B-cell lymphoma in first remission: results of the randomized NHL13 trial.

We investigated rituximab maintenance therapy in patients with diffuse large B-cell lymphoma (n=662) or follicular lymphoma grade 3b (n=21) in first complete remission. Patients were randomized to rituximab maintenance (n=338) or observation (n=345). At a median follow-up of 45 months, the event-free survival rate (the primary endpoint) at 3 years was 80.1% for rituximab maintenance versus 76.5% for observation. This difference was not statistically significant for the intent-to-treat population (likelihood ratio P=0.0670). The hazard ratio by treatment arm was 0.79 (95% confidence interval 0.57-1.08; P=0.1433). The secondary endpoint, progression-free survival was also not met for the whole statistical model (likelihood ratio P=0.3646). Of note, rituximab maintenance was superior to observation when treatment arms only were compared (hazard ratio: 0.62; 95% confidence interval 0.43-0.90; P=0.0120). Overall survival remained unchanged (92.0 versus 90.3%). In subgroup analysis male patients benefited from rituximab maintenance with regards to both event-free survival (84.1% versus 74.4%) (hazard ratio: 0.58; 95% confidence interval 0.36-0.94; P=0.0267) and progression-free survival (89.0% versus 77.6%) (hazard ratio: 0.45; 95% confidence interval 0.25-0.79; P=0.0058). Women had more grade 3/4 adverse events (P=0.0297) and infections (P=0.0341). Men with a low International Prognostic Index treated with rituximab had the best outcome. In summary, rituximab maintenance in first remission after R-CHOP-like treatment did not prolong event-free, progression-free or overall survival of patients with aggressive B-non-Hodgkin lymphoma. The significantly better outcome of men warrants further studies prior to the routine use of rituximab maintenance in men with low International Prognostic Index. This trial is registered under EUDRACT #2005-005187-90 and www.clinicaltrials.gov as #NCT00400478.

Disappearance of Antiphospholipid Antibodies after anti-CD19 CAR T-Cell Therapy of B-Cell Lymphoma in a Patient with Systemic Lupus Erythematosus and Antiphospholipid Syndrome.

Antiphospholipid syndrome is an autoimmune disorder characterized by the development of spontaneous venous, arterial, or microvascular thrombosis and/or pregnancy-related complications (e.g. miscarriages, fetal loss) in the presence of persistent antiphospholipid antibodies (aPL). Current state-of-the-art treatment consists of indefinite anticoagulation with vitamin K antagonists to prevent recurrence of thrombotic events. This, however, only represents a symptom-control oriented treatment approach. Until today, no curative option eradicating aPL permanently or addressing the underlying pathomechanism has been established. Here, we report the case of a woman with systemic lupus erythematosus and antiphospholipid syndrome with triple aPL-positivity who developed recurrent deep veinous thrombosis. After receiving CAR T-Cell therapy for aggressive B-Cell lymphoma, sustained eradication of all three aPL subtypes was observed, suggesting a promising role of immunotherapies targeting anti-CD19 for the treatment of pro-thrombotic autoimmune disorders.

Rituximab serum concentrations during immuno-chemotherapy of follicular lymphoma correlate with patient gender, bone marrow infiltration and clinical response.

BACKGROUND: Treatment of follicular lymphoma with rituximab is currently recommended at a dose of 375 mg/m(2). We aimed to provide a rationale for optimal dosing and scheduling of this anti-CD20 antibody based on pharmacokinetics. DESIGN AND METHODS: Clinical efficacy of immunochemotherapy with rituximab, fludarabine and mitoxantrone followed by 2-monthly rituximab maintenance was evaluated in 29 patients with previously untreated follicular lymphoma in a prospective phase II trial (AGMT-NHL9). Pharmacokinetic analysis was assessed in 17 patients. RESULTS: Induction treatment resulted in high clinical response rates (complete remission 66%; ORR 100%). Significantly higher complete remission rates were observed in female patients (86 vs. 47%; Odds Ratio 6.8, 95% CI: 1.12; 41.82; P=0.05). Rituximab pharmacokinetic analysis showed a high variability ranging over almost 1 order of magnitude at maintenance cycle 1 (area under the curve 1,540-12,025 g/L*days). Median area under the curve was lower in men (81%) and in patients with initial bone marrow infiltration (76%). Higher rituximab serum concentrations before next therapy (C(trough)) were associated with female sex (P=0.04) as well as with absence of initial bone marrow infiltration (P=0.001). C(trough) correlated with remission quality (complete vs. partial remission; P=0.005) and progression-free survival (P=0.03). A decline in rituximab C(trough) below 25,000 ng/mL was observed 9.5 to 62 months before clinical relapse (P=0.008). CONCLUSIONS: The results of this pilot trial suggest that more differentiated dosing schedules based on gender and bone marrow infiltration should be explored for rituximab therapy for lymphoma. This study was registered in ClinicalTrials.gov (Identifier: NCT01560117).

The frequency of differentiated CD3+CD27-CD28- T cells predicts response to CART cell therapy in diffuse large B-cell lymphoma.

Background: Chimeric antigen receptor T (CART) cell therapy targeting the B cell specific differentiation antigen CD19 has shown clinical efficacy in a subset of relapsed/refractory (r/r) diffuse large B cell lymphoma (DLBCL) patients. Despite this heterogeneous response, blood pre-infusion biomarkers predicting responsiveness to CART cell therapy are currently understudied. Methods: Blood cell and serum markers, along with clinical data of DLBCL patients who were scheduled for CART cell therapy were evaluated to search for biomarkers predicting CART cell responsiveness. Findings: Compared to healthy controls (n=24), DLBCL patients (n=33) showed significant lymphopenia, due to low CD3+CD4+ T helper and CD3-CD56+ NK cell counts, while cytotoxic CD3+CD8+ T cell counts were similar. Although lymphopenic, DLBCL patients had significantly more activated HLA-DR+ (P=0.005) blood T cells and a higher frequency of differentiated CD3+CD27-CD28- (28.7 ± 19.0% versus 6.6 ± 5.8%; P<0.001) T cells. Twenty-six patients were infused with CART cells (median 81 days after leukapheresis) and were analyzed for the overall response (OR) 3 months later. Univariate and multivariate regression analyses showed that low levels of differentiated CD3+CD27-CD28- T cells (23.3 ± 19.3% versus 35.1 ± 18.0%) were independently associated with OR. This association was even more pronounced when patients were stratified for complete remission (CR versus non-CR: 13.7 ± 11.7% versus 37.7 ± 17.4%, P=0.001). A cut-off value of ≤ 18% of CD3+CD27-CD28- T cells predicted CR at 12 months with high accuracy (P<0.001). In vitro, CD3+CD8+CD27-CD28- compared to CD3+CD8+CD27+CD28+ CART cells displayed similar CD19+ target cell-specific cytotoxicity, but were hypoproliferative and produced less cytotoxic cytokines (IFN-γ and TNF-α). CD3+CD8+ T cells outperformed CD3+CD4+ T cells 3- to 6-fold in terms of their ability to kill CD19+ target cells. Interpretation: Low frequency of differentiated CD3+CD27-CD28- T cells at leukapheresis represents a novel pre-infusion blood biomarker predicting a favorable response to CART cell treatment in r/r DLBCL patients.

The cancer survival index-A prognostic score integrating psychosocial and biological factors in patients diagnosed with cancer or haematologic malignancies.

OBJECTIVE: We aimed to investigate whether (1) psychological and social indicators influence survival in patients diagnosed with cancer or haematologic malignancies when important biological aspects are controlled for, (2) psychological, social and biological indicators can be utilised to design one collated index for survival, usable in clinical practice to identify patients at risk of shorter survival and to improve personalised healthcare provision. METHODS: In this cross-sectional study, 2263 patients with cancer or haematologic malignancies participated. We analysed 15 biological, psychological and social indicators as risk factors for survival with a Cox proportional hazards model. Indicators significantly associated with survival were combined to compute models for the identification of patient groups with different risks of death. The training sample contained 1122 patients. Validation samples included the remaining 1141 patients, the total sample, as well as groups with different cancer entities. RESULTS: Five indicators were found to significantly impact survival: Cancer site (HR: 3.56), metastatic disease (HR: 1.88), symptoms of depression (HR: 1.34), female sex (HR: 0.73) and anaemia (HR: 0.48). Combining these indicators to a model, we developed the Cancer Survival Index, identifying three distinct groups of patients with estimated survival times of 47.2 months, 141 months and 198.2 months (p < 0.001). Post hoc analysis of the influence of depression on survival showed a mediating effect of the following four factors, related to both depression and survival: previous psychiatric conditions, employment status, metastatic disease and haemoglobin levels. CONCLUSIONS: Psychosocial and biological factors impact survival in various malignancies and can be utilised jointly to compute an index for estimating the survival of each patient individually-the Cancer Survival Index.

Prolonged progression-free survival in patients with chronic lymphocytic leukemia receiving granulocyte colony-stimulating factor during treatment with fludarabine, cyclophosphamide, and rituximab.

The clinical benefit of the addition of granulocyte colony-stimulating factor (G-CSF) to standard immunochemotherapy of chronic lymphocytic leukemia (CLL) with fludarabine, cyclophosphamide, and rituximab (FCR) is still unclear. In this retrospective study we analyzed the outcome of 32 consecutive patients with CLL during treatment with FCR. Sixteen patients received G-CSF for treatment of CTC grade 3 or 4 neutropenia or febrile neutropenia at some point during therapy and 16 did not. Both groups were well balanced for clinical and biological risk factors. Overall response rates were not significantly different (94% vs. 75%; p=0.144). Interestingly, a significantly better progression-free survival (100% vs. 35.4% at 24 months; p<0.001) and even overall survival (100% vs. 77.8% at 24 months; p=0.022) was observed in patients receiving G-CSF. While the underlying cause remains to be elucidated, these data strongly suggest an association of the addition of G-CSF to FCR therapy with final patient outcome.

Prevalence and clinical impact of autoimmune diseases and chronic infections in malignant lymphomas at diagnosis.

There is increasing evidence for the role of chronic antigenic stimulation (CS) in the development of cancer. Clinical data, however, are rare as is the information on outcome. In this study, the occurrence of chronic infections (CI) and autoimmune diseases (AI) in patients with malignant lymphoma at diagnosis was assessed. Of 367 patients [non-Hodgkin's lymphoma (NHL) N = 297, Hodgkin's lymphoma N = 70], 9.8% (N = 36) had a history of chronic antigenic stimulation (4.4% AI, 5.4% CI) at diagnosis. After a median observation time of 74.7 months, 118 patients have died. There were more male patients in this cohort. However, sex ratio among patients with chronic antigenic stimulation was skewed in favor of women (p = 0.018), in particular among lymphoma patients with AI (p = 0.001). NHL patients with autoimmune diseases showed a tendency to develop diffuse large B cell lymphoma [8 of 12 AI + NHL patients (66.7%) vs. 100 of 266 non-CS NHL (37.6%); p = 0.066]. No significant difference in overall survival (OS) between CS and non-CS patients could be observed (median OS after 48 months was: CS 77.7% vs. non-CS 71.8%). In conclusion, chronic antigenic stimulation at diagnosis appears to be associated with a higher prevalence in women, in particular among patients with autoimmune disease. However, no difference in overall survival was observed. This suggests that the presence of chronic inflammatory conditions does not decisively influence the outcome of lymphoma patients.

Influence of TP53 Mutation on Survival of Diffuse Large B-Cell Lymphoma in the CAR T-Cell Era.

Refractory/relapsed diffuse large B-cell lymphoma (DLBCL) is associated with poor outcome. The clinical behavior and genetic landscape of DLBCL is heterogeneous and still not fully understood. TP53 mutations in DLBCL have been identified as markers of poor prognosis and are often associated with therapeutic resistance. Chimeric antigen receptor T-cell therapy is an innovative therapeutic concept and represents a game-changing therapeutic option by supporting the patient's own immune system to kill the tumor cells. We investigated the impact of TP53 mutations on the overall survival of refractory/relapsed DLBCL patients treated with comparable numbers of therapy lines. The minimum number of therapy lines was 2 (median 4), including either anti-CD19 CAR T-cell therapy or conventional salvage therapy. A total of 170 patients with DLBCL and high-grade B-cell lymphoma with MYC, BCL2, and/or BCL6 rearrangements (DHL/THL), diagnosed and treated in our hospital between 2000 and 2021, were included. Twenty-nine of them received CAR T-cell therapy. TP53 mutations were found in 10/29 (35%) and 31/141 (22%) of patients in the CAR T-cell and conventional groups, respectively. Among the 141 patients not treated with CAR T cells, TP53 mutation was an independent prognostic factor for overall survival (OS) (median 12 months with TP53 vs. not reached without TP53 mutation, p < 0.005), but in the CAR T cell treated group, this significance could not be shown (median OS 30 vs. 120 months, p = 0.263). The findings from this monocentric retrospective study indicate that TP53 mutation status does not seem to affect outcomes in DLBCL patients treated with CAR T-cell therapy. Detailed evaluation in large cohorts is warranted.

Nonpegylated liposomal doxorubicin is highly active in patients with B and T/NK cell lymphomas with cardiac comorbidity or higher age.

We used nonpegylated liposomal doxorubicin (NPLD) in cytostatic drug combinations to treat 37 patients with non-Hodgkin's lymphoma and pre-existing cardiac disorder or elderly patients with reduced physical state who were ineligible for conventional anthracycline-containing therapy. High remission rates were observed in this poor-risk population: Complete remission rates were 75% for diffuse large B cell lymphoma (DLBCL) and 55% for T/NK cell neoplasm (overall response rate of 80% and 89%, respectively). Twenty-seven patients (73%) are still alive after a median observation time of 14 months. No major cardiac or gastrointestinal toxicity was observed. Extravasation of NPLD in two patients resulted in mild inflammation without tissue damage. Hematologic toxicity was comparable to that of conventional anthracycline-containing regimens. We conclude that NPLD is highly active in combination chemotherapy for lymphoma with low cardiac toxicity in patients with pre-existing cardiac disorders or higher age. Moreover, we also observed remarkable efficacy in T/NK cell lymphomas.

Autoimmune thrombocytopenia in non-Hodgkin's lymphomas.

Autoimmune thrombocytopenia is a common immunehematologic complication in non-Hodgkin's lymphomas and may complicate the treatment. We analyzed an original series from our institute as well as published cases of non-Hodgkin's lymphomas (excluding chronic lymphocytic leukemia) associated with autoimmune thrombocytopenia with regard to demographic factors, prevalence in non-Hodgkin's lymphoma subtypes and treatment outcome. The male/female ratio is 1.75. Half of the cases occurred prior to diagnosis of lymphoma. Chemotherapy is the best treatment in many non-Hodgkin's lymphomas patients with autoimmune thrombocytopenia compared with standard treatment of autoimmune thrombocytopenia. Splenectomy is effective in splenic marginal zone lymphoma. Autoimmune thrombocytopenia in patients with non-Hodgkin's lymphomas is potentially life-threatening and difficult to treat.

Autoimmune conditions and chronic infections in chronic lymphocytic leukemia patients at diagnosis are associated with unmutated IgVH genes.

Few data are available concerning the prevalence of autoimmune disease or chronic infections in chronic lymphocytic leukemia patients at diagnosis as well as their clinical outcome. We studied the frequency of such chronic conditions in relation to prognostic markers. A history of autoimmune disease or chronic infection was found in 21% of 186 chronic lymphocytic leukemia patients (12% in autoimmune diseases, 9% in chronic infections). Patients with a history of chronic stimulation were more likely to have unmutated IgV(H) genes (p<0.002), unfavorable or intermediate risk cytogenetics (11q, 17p deletions, trisomy 12) (p<0.001), and higher CD38 expression (p=0.004). Autoimmune conditions (n=22) were characterized by female predominance (55.0%) with a high frequency of unmutated IgV(H) (53,8%). Median time to first treatment was 83 months for the chronic stimulation group compared to 128 months for the non-chronic stimulation group (n.s.). Patients suffering from chronic conditions at chronic lymphocytic leukemia diagnosis are likely to have poor prognostic markers, particularly unmutated IgV(H) genes.

[68Ga]Ga-Pentixafor PET/MRI for CXCR4 Imaging of Chronic Lymphocytic Leukemia: Preliminary Results.

OBJECTIVES: This prospective proof-of-principle study aimed to determine whether [Ga]Ga-Pentixafor uptake, which reflects CXCR4 expression, is higher in the bone marrow of chronic lymphocytic leukemia (CLL) than in other oncological diseases without bone marrow infiltration and can therefore be used for CLL imaging. MATERIALS AND METHODS: Thirteen CLL patients and 20 controls (10 with pancreatic adenocarcinoma and 10 with mucosa-associated lymphoid tissue lymphoma) with histologically proven cancer underwent [Ga]Ga-Pentixafor positron emission tomography/magnetic resonance imaging. Standardized [Ga]Ga-Pentixafor uptake values (SUVmax, SUVmean) were measured in the bone marrow of the pelvis, the lumbar vertebra L4, and the bony structure with the visually highest tracer uptake ("hottest lesion"). Mean apparent diffusion coefficient values were also measured in the pelvis. Serum leukocyte count (gram per liter), lymphocyte percentage (percent), lactate dehydrogenase (unit per liter), ß2-microglobulin (milligram per deciliter), and C-reactive protein (milligram per deciliter) were measured. Statistical analyses comprised analysis of variance with Games-Howell post hoc tests and Spearman correlation coefficients. RESULTS: SUVmax and SUVmean differed significantly between CLL and pancreatic adenocarcinoma in the pelvis (P = 0.032 and P = 0.008) and lumbar vertebra L4 (both P < 0.001). SUVmean also differed in the pelvis (P = 0.020) and L4 (P = 0.041), and SUVmax in L4 (P = 0.019), between CLL and mucosa-associated lymphoid tissue lymphoma. Receiver operating characteristic-based areas under the curve for separation of CLL from the control groups were greatest for the SUVmax of the bony structure with the strongest [Ga]Ga-Pentixafor uptake (0.94) and the SUVmax of L4 (0.92). There was no significant correlation between [Ga]Ga-Pentixafor uptake and pelvic apparent diffusion coefficients or serum parameters. CONCLUSIONS: [Ga]Ga-Pentixafor positron emission tomography/magnetic resonance imaging may possibly be useful for CXCR4-based CLL imaging.