Sensitizing protective tumor microenvironments to antibody-mediated therapy.

Therapy-resistant microenvironments represent a major barrier toward effective elimination of disseminated malignancies. Here, we show that select microenvironments can underlie resistance to antibody-based therapy. Using a humanized model of treatment refractory B cell leukemia, we find that infiltration of leukemia cells into the bone marrow rewires the tumor microenvironment to inhibit engulfment of antibody-targeted tumor cells. Resistance to macrophage-mediated killing can be overcome by combination regimens involving therapeutic antibodies and chemotherapy. Specifically, the nitrogen mustard cyclophosphamide induces an acute secretory activating phenotype (ASAP), releasing CCL4, IL8, VEGF, and TNFα from treated tumor cells. These factors induce macrophage infiltration and phagocytic activity in the bone marrow. Thus, the acute induction of stress-related cytokines can effectively target cancer cells for removal by the innate immune system. This synergistic chemoimmunotherapeutic regimen represents a potent strategy for using conventional anticancer agents to alter the tumor microenvironment and promote the efficacy of targeted therapeutics.

Entirely noninvasive outcome prediction in central nervous system lymphomas using circulating tumor DNA.

ABSTRACT: State-of-the-art response assessment of central nervous system lymphoma (CNSL) by magnetic resonance imaging is challenging and an insufficient predictor of treatment outcomes. Accordingly, the development of novel risk stratification strategies in CNSL is a high unmet medical need. We applied ultrasensitive circulating tumor DNA (ctDNA) sequencing to 146 plasma and cerebrospinal fluid (CSF) samples from 67 patients, aiming to develop an entirely noninvasive dynamic risk model considering clinical and molecular features of CNSL. Our ultrasensitive method allowed for the detection of CNSL-derived mutations in plasma ctDNA with high concordance to CSF and tumor tissue. Undetectable plasma ctDNA at baseline was associated with favorable outcomes. We tracked tumor-specific mutations in plasma-derived ctDNA over time and developed a novel CNSL biomarker based on this information: peripheral residual disease (PRD). Persistence of PRD after treatment was highly predictive of relapse. Integrating established baseline clinical risk factors with assessment of radiographic response and PRD during treatment resulted in the development and independent validation of a novel tool for risk stratification: molecular prognostic index for CNSL (MOP-C). MOP-C proved to be highly predictive of outcomes in patients with CNSL (failure-free survival hazard ratio per risk group of 6.60; 95% confidence interval, 3.12-13.97; P < .0001) and is publicly available at www.mop-c.com. Our results highlight the role of ctDNA sequencing in CNSL. MOP-C has the potential to improve the current standard of clinical risk stratification and radiographic response assessment in patients with CNSL, ultimately paving the way toward individualized treatment.

Reassessing the chronic lymphocytic leukemia International Prognostic Index in the era of targeted therapies.

ABSTRACT: We evaluated the chronic lymphocytic leukemia International Prognostic Index (CLL-IPI) in patients with CLL treated first line with targeted drugs (n = 991) or chemoimmunotherapy (n = 1256). With a median observation time of 40.5 months, the 3-year progression-free survival (PFS) rates for targeted drug-treated patients varied by CLL-IPI risk group: 96.5% (low), 87.6% (intermediate), 82.4% (high), and 78.7% (very high). Differences between consecutive CLL-IPI risk groups were observed for intermediate vs low and high vs intermediate, but not very high vs high. CLL-IPI factors ß2-microglobulin, immunoglobulin heavy variable (IGHV) status, and TP53 status each retained prognostic value for PFS. The 3-year overall survival (OS) rates by CLL-IPI risk groups were 100%, 96%, 93.9%, and 89.4%, respectively, with no differences between consecutive risk groups. Age, Binet stage, ß2-microglobulin, and TP53 status each retained prognostic value for OS. In chemoimmunotherapy patients (median observation time, 66.9 months), 3-year PFS rates for CLL-IPI risk groups were 78.1%, 51.4%, 40.1%, and 16.5%, respectively; corresponding 3-year OS rates were 97.4%, 93.1%, 81.8%, and 57.3%. In a matched-pair analysis, PFS differences in targeted therapies (n = 812) vs chemoimmunotherapy (n = 812) across all risk groups and OS differences in all but patients at low risk were demonstrated. The CLL-IPI maintains its prognostic value in predicting PFS outcomes with targeted drugs, but its impact in predicting survival appears diminished. Targeted therapies showed enhanced outcomes over chemoimmunotherapy, highlighting their effectiveness across various risk groups. Our findings support ongoing assessment of prognostic tools in CLL treatment evolution. These trials were registered at www.ClinicalTrials.gov as #NCT02345863, #NCT02401503, #NCT02689141, #NCT02445131, #NCT02758665, #NCT02950051, #NCT02242942, #NCT00262782, #NCT00281918, and #NCT01010061.

First-line venetoclax combinations versus chemoimmunotherapy in fit patients with chronic lymphocytic leukaemia (GAIA/CLL13): 4-year follow-up from a multicentre, open-label, randomised, phase 3 trial.

BACKGROUND: In the primary analysis report of the GAIA/CLL13 trial, we found that venetoclax-obinutuzumab and venetoclax-obinutuzumab-ibrutinib improved undetectable measurable residual disease (MRD) rates and progression-free survival compared with chemoimmunotherapy in patients with previously untreated chronic lymphocytic leukaemia. However, to our knowledge, no data on direct comparisons of different venetoclax-based combinations are available. METHODS: GAIA/CLL13 is an open-label, randomised, phase 3 study conducted at 159 sites in ten countries in Europe and the Middle East. Eligible patients were aged 18 years or older, with a life expectancy of at least 6 months, an Eastern Cooperative Oncology group performance status of 0-2, a cumulative illness rating scale score of 6 or lower or a single score of 4 or lower, and no TP53 aberrations. Patients were randomly assigned (1:1:1:1), with a computer-generated list stratified by age, Binet stage, and regional study group, to either chemoimmunotherapy, venetoclax-rituximab, venetoclax-obinutuzumab, or venetoclax-obinutuzumab-ibrutinib. All treatments were administered in 28-day cycles. Patients in the chemoimmunotherapy group received six cycles of treatment, with patients older than 65 years receiving intravenous bendamustine (90 mg/m2, days 1-2), whereas patients aged 65 years or younger received intravenous fludarabine (25 mg/m2, days 1-3) and intravenous cyclophosphamide (250 mg/m2, days 1-3). Intravenous rituximab (375 mg/m2, day 1 of cycle 1; 500 mg/m2, day 1 of cycles 2-6) was added to chemotherapy. In the experimental groups, patients received daily venetoclax (400 mg orally) for ten cycles after a 5-week ramp-up phase starting on day 22 of cycle 1. In the venetoclax-rituximab group, intravenous rituximab (375 mg/m2, day 1 of cycle 1; 500 mg/m2, day 1 of cycles 2-6) was added. In the obinutuzumab-containing groups, obinutuzumab was added (cycle 1: 100 mg on day 1, 900 mg on day 2, and 1000 mg on days 8 and 15; cycles 2-6: 1000 mg on day 1). In the venetoclax-obinutuzumab-ibrutinib group, daily ibrutinib (420 mg orally, from day 1 of cycle 1) was added until undetectable MRD was reached in two consecutive measurements (3 months apart) or until cycle 36. The planned treatment duration was six cycles in the chemoimmunotherapy group, 12 cycles in the venetoclax-rituximab and the venetoclax-obinutuzumab group and between 12 and 36 cycles in the venetoclax-obinutuzumab-ibrutinib group. Coprimary endpoints were the undetectable MRD rate in peripheral blood at month 15 for the comparison of venetoclax-obinutuzumab versus standard chemoimmunotherapy and investigator-assessed progression-free survival for the comparison of venetoclax-obinutuzumab-ibrutinib versus standard chemoimmunotherapy, both analysed in the intention-to-treat population (ie, all patients randomly assigned to treatment) with a split α of 0·025 for each coprimary endpoint. Both coprimary endpoints have been reported elsewhere. Here we report a post-hoc exploratory analysis of updated progression-free survival results after a 4-year follow-up of our study population. Safety analyses included all patients who received at least one dose of study treatment. This study is registered with ClinicalTrials.gov, NCT02950051, recruitment is complete, and all patients are off study treatment. FINDINGS: Between Dec 13, 2016, and Oct 13, 2019, 1080 patients were screened and 926 were randomly assigned to treatment (chemoimmunotherapy group n=229; venetoclax-rituximab group n=237; venetoclax-obinutuzumab group n=229; and venetoclax-obinutuzumab-ibrutinib group n=231); mean age 60·8 years (SD 10·2), 259 (28%) of 926 patients were female, and 667 (72%) were male (data on race and ethnicity are not reported). At data cutoff for this exploratory follow-up analysis (Jan 31, 2023; median follow-up 50·7 months [IQR 44·6-57·9]), patients in the venetoclax-obinutuzumab group had significantly longer progression-free survival than those in the chemoimmunotherapy group (hazard ratio [HR] 0·47 [97·5% CI 0·32-0·69], p<0·0001) and the venetoclax-rituximab group (0·57 [0·38-0·84], p=0·0011). The venetoclax-obinutuzumab-ibrutinib group also had a significantly longer progression-free survival than the chemoimmunotherapy group (0·30 [0·19-0·47]; p<0·0001) and the venetoclax-rituximab group (0·38 [0·24-0·59]; p<0·0001). There was no difference in progression-free survival between the venetoclax-obinutuzumab-ibrutinib and venetoclax-obinutuzumab groups (0·63 [0·39-1·02]; p=0·031), and the proportional hazards assumption was not met for the comparison between the venetoclax-rituximab group versus the chemoimmunotherapy group (log-rank p=0·10). The estimated 4-year progression-free survival rate was 85·5% (97·5% CI 79·9-91·1; 37 [16%] events) in the venetoclax-obinutuzumab-ibrutinib group, 81·8% (75·8-87·8; 55 [24%] events) in the venetoclax-obinutuzumab group, 70·1% (63·0-77·3; 84 [35%] events) in the venetoclax-rituximab group, and 62·0% (54·4-69·7; 90 [39%] events) in the chemoimmunotherapy group. The most common grade 3 or worse treatment-related adverse event was neutropenia (114 [53%] of 216 patients in the chemoimmunotherapy group, 109 [46%] of 237 in the venetoclax-rituximab group, 127 [56%] of 228 in the venetoclax-obinutuzumab group, and 112 [48%] of 231 in the venetoclax-obinutuzumab-ibrutinib group). Deaths determined to be associated with study treatment by the investigator occurred in three (1%) patients in the chemoimmunotherapy group (n=1 due to each of sepsis, metastatic squamous cell carcinoma, and Richter's syndrome), none in the venetoclax-rituximab and venetoclax-obinutuzumab groups, and four (2%) in the venetoclax-obinutuzumab-ibrutinib group (n=1 due to each of acute myeloid leukaemia, fungal encephalitis, small-cell lung cancer, and toxic leukoencephalopathy). INTERPRETATION: With more than 4 years of follow-up, venetoclax-obinutuzumab and venetoclax-obinutuzumab-ibrutinib significantly extended progression-free survival compared with both chemoimmunotherapy and venetoclax-rituximab in previously untreated, fit patients with chronic lymphocytic leukaemia, thereby supporting their use and further evaluation in this patient group, while still considering the higher toxicities observed with the triple combination. FUNDING: AbbVie, Janssen, and F Hoffmann-La Roche.

Multicenter development of a PET-based risk assessment tool for product-specific outcome prediction in large B-cell lymphoma patients undergoing CAR T-cell therapy.

PURPOSE: The emergence of chimeric antigen receptor (CAR) T-cell therapy fundamentally changed the management of individuals with relapsed and refractory large B-cell lymphoma (LBCL). However, real-world data have shown divergent outcomes for the approved products. The present study therefore set out to evaluate potential risk factors in a larger cohort. METHODS: Our analysis set included 88 patients, treated in four German university hospitals and one Italian center, who had undergone 2-[18F]fluoro-2-deoxy-D-glucose positron emission tomography (PET) before CAR T-cell therapy with tisagenlecleucel or axicabtagene ciloleucel. We first determined the predictive value of conventional risk factors, treatment lines, and response to bridging therapy for progression-free survival (PFS) through forward selection based on Cox regression. In a second step, the additive potential of two common PET parameters was assessed. Their optimal dichotomizing thresholds were calculated individually for each CAR T-cell product. RESULTS: Extra-nodal involvement emerged as the most relevant of the conventional tumor and patient characteristics. Moreover, we found that inclusion of metabolic tumor volume (MTV) further improves outcome prediction. The hazard ratio for a PFS event was 1.68 per unit increase of our proposed risk score (95% confidence interval [1.20, 2.35], P = 0.003), which comprised both extra-nodal disease and lymphoma burden. While the most suitable MTV cut-off among patients receiving tisagenlecleucel was 11 mL, a markedly higher threshold of 259 mL showed optimal predictive performance in those undergoing axicabtagene ciloleucel treatment. CONCLUSION: Our analysis demonstrates that the presence of more than one extra-nodal lesion and higher MTV in LBCL are associated with inferior outcome after CAR T-cell treatment. Based on an assessment tool including these two factors, patients can be assigned to one of three risk groups. Importantly, as shown by our study, metabolic tumor burden might facilitate CAR T-cell product selection and reflect the individual need for bridging therapy.

Long-term remission in a patient with relapsed Richter's transformation treated with CD19-directed chimeric antigen-receptor T-cells after allogeneic stem cell transplantation.

Patients with Richter's transformation of chronic lymphocytic leukemia (CLL) to diffuse large B-cell lymphoma (DLBCL-RT) face a dismal prognosis. A 51-year-old female patient diagnosed with CLL with deletion (17p) in 2009. CLL treatment included chemoimmunotherapy and targeted substances. DLBCL-RT was diagnosed in November 2016. After receiving an allogeneic hematopoietic stem cell transplantation, she relapsed in September 2019 and tisagenlecleucel was infused in December 2019. Cytokine release syndrome grade 2 was treated with two doses of tocilizumab and the patient was started on 140 mg ibrutinib in February 2020. Our patient remains in remission up to 4 years after CAR T-cell treatment.

Fludarabine, cyclophosphamide, and rituximab as first-line treatment in patients with chronic lymphocytic leukemia: A long-term analysis of the German CLL Study Group (GCLLSG) registry.

Long-term data of chronic lymphocytic leukemia (CLL) patients with favorable risk who were treated with fludarabine, cyclophosphamide, and rituximab (FCR) within clinical trials show good efficacy. We here report long-term data collected within the GCLLSG registry. Altogether, 417 CLL patients who received first-line treatment with FCR were analyzed, of which 293 (70.3%) were treated outside of clinical trials. The median observation time from first-line was 95.8 (interquartile range 58.7-126.8) months. Focusing on data of 194 (46.5%) patients who received FCR first-line treatment after 2013 (start of data collection within GCLLSG registry), responses were documented in 85% of the patients, non-responses in 15%, and for 3.6% the assessment was missing. Median event-free survival (EFS, time until disease progression, subsequent treatment, or death) was 60.2 months with a 5-year EFS-rate of 50.6%. Patients with higher-risk disease, characterized by unmutated IGHV (N = 78), had a median EFS of 45.4 months with a 5-year EFS rate of 36.3%, while the median EFS was 77.5 months with a 5-year EFS rate of 60.3% in patients with mutated IGHV (N = 40). Median overall survival was not reached with a 5-year survival rate of 92.7%. In summary, first-line FCR was associated with long EFS, especially in patients exhibiting a mutated IGHV status.

Management of front line chronic lymphocytic leukemia.

Treatment options with targeted agents have changed the treatment landscape of CLL profoundly. Besides chemoimmunotherapy, treatment regimen approved for frontline therapy include continuous treatment with BTK inhibitors like ibrutinib and acalabrutinib or fixed-duration regimen like venetoclax-obinutuzumab with the approval of venetoclax-ibrutinib to be awaited. Although these agents have usually manageable side effects, toxicities might limit choices for the individual patient. We here discuss latest trial data and propose a treatment algorithm for frontline treatment of CLL according to fitness and relevant genetic risk factors like IGHV mutational status and TP53 aberrations.

Health-related quality of life with fixed-duration venetoclax-obinutuzumab for previously untreated chronic lymphocytic leukemia: Results from the randomized, phase 3 CLL14 trial.

Chronic lymphocytic leukemia (CLL)-related symptoms impair the well-being of patients, making improvement of health-related quality of life (QoL) a goal of treatment. The CLL14 trial demonstrated higher efficacy of fixed-duration venetoclax-obinutuzumab (Ven-Obi) compared to chlorambucil-obinutuzumab (Clb-Obi) in patients with previously untreated CLL. To assess patients' QoL, the following patient-reported outcomes (PRO) measures were assessed: the M.D. Anderson Symptom Inventory (MDASI) core instrument and CLL module and the EORTC Quality of Life Questionnaire Core 30 (EORTC QLQ-C30). At treatment start, physical functioning (mean 75.9 [standard deviation (SD) ± 20.1] in the Clb-Obi arm and 76.9 [±19.4] in the Ven-Obi arm), role functioning (73.6 [±27.86] and 72.6 [±26.9]) and GHS/QoL (63.6 [±21.0] and 60.3 [±20.5]) were comparable between treatment arms per EORTC QLQ-C30 scale scores. Baseline levels of physical and role functioning were maintained throughout treatment and follow-up, with no relevant improvement or deterioration. On average, patients treated with Ven-Obi showed a meaningful improvement of GHS/QoL during treatment and follow-up by at least eight points at cycle three, whereas improvement was delayed until cycle eight with Clb-Obi. According to MDASI scores, CLL symptoms (1.5 [±1.2] and 1.6 [±1.3]), core cancer symptoms (1.5 [±1.4] and 1.8 [±1.7]) and symptom interference (2.1 [±2.3] and 2.3 [±2.3]) were generally low and comparable between treatment arms at baseline and were maintained throughout treatment and follow-up. This analysis demonstrates that the higher efficacy of Ven-Obi is not associated with QoL impairment and that Ven-Obi achieves early relief of CLL-related symptoms in elderly unfit patients.

Mode of progression after first line treatment correlates with outcome of chronic lymphocytic leukemia (CLL).

In CLL, progressive disease (PD) following remission after first line treatment can present with varying phenotypes. We hypothesized that the mode of PD correlates with clinical outcomes. Data from three phase III trials of the German CLL Study Group (GCLLSG) (CLL8, CLL10, CLL11) including a total of 2159 patients receiving first line (immuno)-chemotherapy (FCR, FC, CLB, CLB-R, CLB-Ob) were analyzed. Patients were categorized as "ALC" if PD was due to increasing absolute lymphocyte count, or as "Ly" if due to lymphadenopathy. A group of 241 patients progressed with ALC, and 727 progressed with Ly, including 329 who progressed on both modalities. In fit patients, median TTNT after PD in the Ly group was 12.3 months vs 17.0 months in the ALC group (HR 1.299 [1.036-1.628]; P = .024). Median OS after PD was 45.1 months in the Ly group and 42.4 months in the ALC group (HR=1.023 [0.753-1.389]; P = .885). For unfit patients, median TTNT in the Ly group was 11.7 months vs 21.4 months in the ALC group (HR 1.357 [1.051-1.753]; P = .019). Median OS was 42.8 months in the Ly group and not reached in the ALC group (HR 1.851 [1.280-2.677]; P = .001). Patients in the Ly group more frequently showed impairment of quality of life (QoL). This analysis demonstrates that patients with progressive lymphadenopathy have a significantly shorter TTNT, OS and less favorable QoL. Our findings might help physicians to better estimate the clinical course of a progressing CLL patient.

Economic evaluation of chronic lymphocytic leukemia from a hospital management perspective.

OBJECTIVES: Treatment of chronic lymphocytic leukemia (CLL) is currently undergoing dramatic changes. We analyzed economic risks in hospitalized patients with CLL from a management perspective. METHODS: One hundred and twelve patients with CLL hospitalized in 2013 and 2014 at the University Hospital of Cologne were analyzed. To assess profit margins (PMs) per case, diagnosis-related group (DRG) reimbursement data were merged with an internal cost accounting scheme depending on age, prognostic factors, and DRG key performance indicators. RESULTS: In 112 patients, 284 cases coded by 19 different DRG with strongly fluctuating cost revenue ratios were found with an overall negative PM of €137 147. The DRG R61H was identified as the one most commonly coded (174 cases, 61.3%) with a deficit per case of €814. Subanalysis demonstrated that the payments were not cost covering due to excessive length of stay and staff costs. Significant differences in PM per case concerning age, length of stay and number of operation and procedure key (OPS) codes (P < 0.05) were found. CONCLUSION: In our research-driven tertiary care hospital, inpatient treatment of patients with CLL is not cost covering. This analysis demonstrates the need for novel care/reimbursement structures in CLL. From a hospital management perspective, cost revenue controlling is crucial to avoid major economic risks.

Outcome Prediction in Patients With Large B-cell Lymphoma Undergoing Chimeric Antigen Receptor T-cell Therapy.

The introduction of chimeric antigen receptor (CAR) T-cell therapy has led to a fundamental shift in the management of relapsed and refractory large B-cell lymphoma. However, our understanding of risk factors associated with non-response is still insufficient and the search for predictive biomarkers continues. Some parameters measurable on 18F-fluorodeoxyglucose positron emission tomography (PET) may be of additional value in this context. A total of 47 individuals from three German university centers who underwent re-staging with PET prior to CAR T-cell therapy were enrolled into the present study. After multivariable analysis considering tumor characteristics and patient factors that might affect progression-free survival (PFS), we investigated whether metabolic tumor volume (MTV) or maximum standardized uptake value (SUVmax) further improve risk stratification. Their most suitable cut-offs were determined by Cox and logistic regression. Forward selection identified extra-nodal disease as the most predictive factor of those routinely available, and we found it to be associated with significantly inferior overall survival after CAR T-cell treatment (P = 0.012). Furthermore, patients with MTV and SUVmax higher than the optimal threshold of 11 mL and 16.7, respectively, experienced shorter PFS (P = 0.016 and 0.002, respectively). Hence, these risk factors might be useful for selection of individuals likely to benefit from CAR T-cell therapy and their management.

Potential synergy between radiotherapy and CAR T-cells - a multicentric analysis of the role of radiotherapy in the combination of CAR T cell therapy.

BACKGROUND: Chimeric antigen receptor (CAR) T-cell therapy has improved the limited overall survival (OS) of patients with intensively pretreated diffuse large B-cell lymphoma (DLBCL). However, the potentially life-threatening toxicities of CAR T-cells and early relapses remain a challenge. As suggested by smaller monocentric analyses, radiotherapy (RT) in combination with CAR T-cells may have an immunomodulatory effect. METHOD/ RESULTS: In this multicentric retrospective analysis, we investigated potentially synergistic effects of RT and CAR T-cells. Of 78 patients from four centers who received CAR T-cell therapy for DLBCL, 37 patients underwent bridging RT or received salvage RT. RTs (median 36 gray) were well tolerated. Therapy response and disease control of CAR T-cell therapy were comparable after bridging RT or bridging systemic therapy. High-grade neurotoxicity tended to occur less frequently after bridging RT. After further disease progression, patients with localized relapses showed better outcomes, compared to those in advanced stage. In the subgroup with localized relapse, patients receiving salvage RT had an increased OS, vs. those without salvage RT (1-year OS rate 89% vs. 38%, p = 0.03). CONCLUSION: Our analysis demonstrated that RT in combination with CAR T-cells led neither to high-grade toxicities, nor to a decreased response rate. We observed better outcomes of salvage therapies in patients with localized relapses vs. those with advanced stage relapses. Especially the patients who received salvage RTs for localized relapses seem to benefit more. Further analyses are necessary to clarify whether specific synergistic effects exist, such as an enhanced anti-tumor effect of CAR T-cells from RT sensitizing.

CLDN6-specific CAR-T cells plus amplifying RNA vaccine in relapsed or refractory solid tumors: the phase 1 BNT211-01 trial.

The oncofetal antigen Claudin 6 (CLDN6) is highly and specifically expressed in many solid tumors, and could be a promising treatment target. We report dose escalation results from the ongoing phase 1/2 BNT211-01 trial evaluating the safety and feasibility of chimeric antigen receptor (CAR) T cells targeting the CLDN6 with or without a CAR-T cell-amplifying RNA vaccine (CARVac) at two dose levels (DLs) in relapsed/refractory CLDN6-positive solid tumors. The primary endpoints were safety and tolerability, maximum tolerated dose and recommended phase 2 dose (RP2D). Secondary endpoints included objective response rate (ORR) and disease control rate. We observed manageable toxicity, with 10 out of 22 patients (46%) experiencing cytokine release syndrome including one grade 3 event and 1 out of 22 (5%) with grade 1 immune effector cell-associated neurotoxicity syndrome. Dose-limiting toxicities occurred in two patients at the higher DL, resolving without sequelae. CAR-T cell engraftment was robust, and the addition of CARVac was well tolerated. The unconfirmed ORR in 21 evaluable patients was 33% (7 of 21), including one complete response. The disease control rate was 67% (14 of 21), with stable disease in seven patients. Patients with germ cell tumors treated at the higher DL exhibited the highest response rate (ORR 57% (4 of 7)). The maximum tolerated dose and RP2D were not established as the trial has been amended to utilize an automated manufacturing process. A repeat of the dose escalation is ongoing and will identify a RP2D for pivotal trials. ClinicalTrials.gov Identifier: NCT04503278 .

Salvage High-dose Melphalan With Autologous Stem cell Transplantation as Bridge to Consolidation Therapy for Chemoresistant Aggressive B-cell Lymphoma.

BACKGROUND: Patients suffering from refractory aggressive B-cell lymphoma not responding to salvage chemotherapy have a dismal prognosis. CAR T-cells or allogeneic stem cell transplantation (SCT) are potentially curative approaches. However, obtaining a remission, and lowering tumor burden before consolidation seems crucial for long-term efficacy of both treatment modalities. MATERIALS AND METHODS: In this retrospective analysis, we reviewed patients with chemoresistant aggressive B-cell lymphoma, defined as being refractory or progressive to at least second line salvage chemotherapy including the regimen immediately preceding autologous stem cell transplantation (ASCT), treated at 2 tertiary centers, who were eligible for intensive treatment using single agent high-dose (HD) melphalan to obtain a remission before consolidating therapy. RESULTS: We identified 36 patients that received single agent HD melphalan and ASCT as remission induction followed by CAR T-cells or allogeneic stem cell transplantation (SCT). Thirteen of the evaluable patients (39.4%) achieved a partial remission and 9 patients (27.73%) a complete remission, resulting in an overall response rate (ORR) of 66.7%. High remission rates were seen across all subgroups including patients with primary refractory lymphoma (ORR 58.3%), uncontrolled disease and high tumor burden as indicated by increased LDH levels (ORR 66.7% for patients with elevated LDH above 2 times upper limit of norm). 22 patients proceeded to allogeneic SCT and 5 to CAR T-cell therapy. Treatment related mortality of ASCT was 5.5% (2 patients, both due to infections). Two-year overall survival of all patients was 15.8%, primarily due to a high non-relapse mortality (45.5%) of allogeneic SCT patients treated with myeloablative conditioning chemotherapy. CONCLUSION: Single agent HD melphalan produces high remission rates in patients with chemoresistant, uncontrolled aggressive B-cell lymphoma and provides a window of opportunity for consolidation therapy. MICROABSTRACT: Patient with refractory/relapsed aggressive B-cell lymphoma after salvage therapy are an unmet medical need because of their very poor prognosis. In our retrospective analysis of 36 patients we showed that single agent high-dose melphalan can achieve high response rates (ORR 66.7%) even in uncontrolled disease enabling consolidation therapy e.g. with allogeneic stem cell transplantation or CAR T-cell therapy.

miRNA deregulation by epigenetic silencing disrupts suppression of the oncogene PLAG1 in chronic lymphocytic leukemia.

MicroRNAs (miRNA) play a key role in cellular regulation and, if deregulated, in the development of neoplastic disorders including chronic lymphocytic leukemia (CLL). RNAs from primary cells of 50 treatment-naive CLL patients and peripheral B cells of 14 healthy donors were applied to miRNA expression profiling using bead chip technology. In CLL cells, a set of 7 up- and 19 down-regulated miRNAs was identified. Among the miRNAs down-regulated in CLL cells, 6 of 10 miRNA promoters examined showed gain of methylation compared with normal B-cell controls. Subsequent target prediction of deregulated miRNAs revealed a highly significant binding prediction at the 3' untranslated region of the pleomorphic adenoma gene 1 (PLAG1) oncogene. Luciferase reporter assays including site-directed mutagenesis of binding sites revealed a significant regulation of PLAG1 by miR-181a, miR-181b, miR-107, and miR-424. Although expression of PLAG1 mRNA was not affected, PLAG1 protein expression was shown to be significantly elevated in CLL cells compared with the levels in healthy donor B cells. In summary, we could demonstrate disruption of miRNA-mediated translational control, partly due to epigenetic transcriptional silencing of miRNAs, with subsequent overexpression of the oncogenic transcription factor PLAG1 as a putative novel mechanism of CLL pathogenesis.

Overexpression of TOSO in CLL is triggered by B-cell receptor signaling and associated with progressive disease.

Resistance toward apoptotic stimuli mediated by overexpression of antiapoptotic factors or extracellular survival signals is considered to be responsible for accumulation of malignant B cells in chronic lymphocytic leukemia (CLL). TOSO was identified as overexpressed candidate gene in CLL, applying unit-transformation assays of publicly available microarray datasets. Based on CLL samples from 106 patients, TOSO was identified to exhibit elevated relative expression (RE) of 6.8 compared with healthy donor B cells using quantitative real-time polymerase chain reaction (PCR; P = .004). High levels of TOSO expression in CLL correlated with high leukocyte count, advanced Binet stage, previous need for chemotherapy, and unmutated IgV(H) status. CD38(+) CLL subsets harboring proliferative activity showed enhanced TOSO expression. We evaluated functional mechanisms of aberrant TOSO expression and identified TOSO expression significantly induced by B-cell receptor (BCR) stimulation compared with control cells (RE; 8.25 vs 4.86; P = .01). In contrast, CD40L signaling significantly reduced TOSO expression (RE, 2.60; P = .01). In summary, we show that the antiapoptotic factor TOSO is associated with progressive disease and enhanced in the proliferative CD38(+) CLL subset. Both association with unmutated IgV(H) and the specific induction of TOSO via the BCR suggest autoreactive BCR signaling as a key mediator of apoptosis resistance in CLL.

Long Term Follow-up Data and Health-Related Quality of Life in Frontline Therapy of Fit Patients Treated With FCR Versus BR (CLL10 Trial of the GCLLSG).

Fludarabine, cyclophosphamide and rituximab (FCR) was compared to bendamustine and rituximab (BR) in an international, randomized, open label, phase 3 trial in 561 previously untreated, fit patients with chronic lymphocytic leukemia (CLL) without del (17p). Primary endpoint was progression free survival (PFS). The final primary endpoint analysis after 37.1 months median follow up failed to show the non-inferiority of BR as compared with FCR. With extended median follow up of 58.2 months, median PFS was 42.3 months in BR-treated patients versus 57.6 months for FCR-treated patients (Hazard Ratio [HR] 1.593; 95% CI 1.271-1.996; p < 0.0001). For patients > 65 years, median PFS was 48.5 months with BR versus 57.9 months with FCR without reaching statistical significance (HR 1.352; 95% CI 0.912-2.006; p = 0.134). Median OS was not reached for both arms with 5-year OS rates of 80.1% vs 80.9%, respectively (HR 1.108; 95% CI 0.755-1.627; p = 0.599). No statistically significant difference was found in the time to secondary malignancy between the 2 groups (at 5 years, 86.6% free from secondary malignancies in the BR group vs 83.8% in the FCR group [HR 0.801; 95% CI 0.507-1.267; p = 0.344]). In patients >65 years secondary neoplasia occurred more frequently after FCR treatment [28 of 86 (32.6%) patients] as compared with BR [18 of 107 (16.8%) patients; p = 0.011]. Health-related quality of life was similar in both treatments. Despite the improved PFS for FCR, OS did not differ. These results also suggest an increase in secondary neoplasia associated with FCR in elderly fit CLL patients.