Incidence of pleural effusion with dasatinib and the effect of switching therapy to a different TKI in patients with chronic phase CML.

Dasatinib is one of the second generation tyrosine kinase inhibitors (TKI) which is approved for the treatment of patients with chronic phase CML (CP-CML) both in the front line and in the second line setting. Pleural effusion (PE) is a unique toxicity associated with dasatinib use. Our aim was to study the incidence of pleural effusion in our cohort of patients who were treated with dasatinib for CP-CML and the safety upon TKI switch. A total of 390 patients were treated with dasatinib during their course of treatment for CP-CML. A total of 69 patients (17.6%) developed any grade of PE. About 33 (48%) patients developed CTCAE grade 2 PE, 34 (49%) grade 3 and only 1 patient developed grade 4 PE. Recurrence of PE was observed in 34 (49%) patients. While only 12 patients (17.3%) continued using dasatinib after development of PE, dasatinib was discontinued in the other 57 patients. Therapy was switched to bosutinib in 13 patients out of which 6 (46%) patients re-developed PE. While only 12.5% patients developed re-accumulation of pleural fluid in patients switched to imatinib, none of the patients switched to nilotinib re-developed PE. A change in TKI to bosutinib was associated with a 46% risk of recurrence of PE in patients who develop PE on dasatinib for the treatment of CP-CML. The incidence of recurrent PE was markedly lower in patient switched to imatinib or nilotinib.

Long-term follow up of the combination of ofatumumab, high-dose methylprednisolone, and lenalidomide for untreated chronic lymphocytic leukemia with biomarker analysis.

BACKGROUND: Advancements in frontline therapy and chemotherapy-sparing treatments in chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) have altered the treatment algorithms of this disease. We present a frontline alternative for treatment- naïve (TN) CLL/SLL patients. METHODS: This was a single-center, phase 2 study of high-dose methylprednisolone (HDMP) and ofatumumab with lenalidomide and ofatumumab consolidative therapy for all comers with TN CLL/SLL. Treatment was continued until disease progression or intolerable side effects. Patients were assessed for response per iwCLL 2008 criteria after completing cycles 3 and 12. RESULTS: Forty-five patients were enrolled (median age, 62.6 years). High-risk features included del17p (18%), Del11q (22%), and unmutated IGHV gene (76%). Median treatment duration was 32·2 (2·7-75·9) months. Thirty-six patients discontinued treatment due to disease progression (22%), adverse events (40%), allogeneic hematopoietic cell transplantation (allo-HCT) (7%), consent withdrawal (4%), and secondary malignancies (7%). The best overall and complete response rates were 96& and 29% respectively. At median follow-up of 61·7 (5·6-84·9) months, 9 patients remained on treatment. Median progression-free survival was 54·4 (2·9-77·6) months. Three patients underwent allo-HCT after a median of 3 (3-4) treatment cycles. Treatment was well tolerated, with a grade 3/4 infusion reaction in one patient. The most common grade 3/4 hematological adverse event was neutropenia (69%). Four patients had grade 3/4 infections. No grade 3/4 tumor flares, tumor lysis syndrome, or thrombosis were observed. CONCLUSION: The combination of ofatumumab, HDMP, and lenalidomide was effective and relatively well tolerated in treatment-naive CLL/SLL. Its role in the frontline setting remains unclear given the current available and effective treatment options. FUNDING: The funders had no role in the study.

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.

Dose modification dynamics of ponatinib in patients with chronic-phase chronic myeloid leukemia (CP-CML) from the PACE and OPTIC trials.

Ponatinib, the only approved all known-BCR::ABL1 inhibitor, is a third-generation tyrosine-kinase inhibitor (TKI) designed to inhibit BCR::ABL1 with or without any single resistance mutation, including T315I, and induced robust and durable responses at 45 mg/day in patients with CP-CML resistant to second-generation TKIs in the PACE trial. However, cardiovascular toxicities, including arterial occlusive events (AOEs), have emerged as treatment-related AEs within this class of TKIs. The OPTIC trial evaluated the efficacy and safety of ponatinib using a novel, response-based, dose-reduction strategy in patients with CP-CML whose disease is resistant to ≥2 TKIs or who harbor T315I. To assess the dose-response relationship and the effect on the safety of ponatinib, we examined the outcomes of patients with CP-CML enrolled in PACE and OPTIC who received 45 mg/day of ponatinib. A propensity score analysis was used to evaluate AOEs across both trials. Survival rates and median time to achieve ≤1% BCR::ABL1IS in OPTIC were similar or better than in PACE. The outcomes of patients with T315I mutations were robust in both trials. Patients in OPTIC had a lower exposure-adjusted incidence of AOEs compared with those in PACE. This analysis demonstrates that response-based dosing for ponatinib improves treatment tolerance and mitigates cardiovascular risk.

Estimated Savings After Stopping Tyrosine Kinase Inhibitor Treatment Among Patients With Chronic Myeloid Leukemia.

Importance: Patients with chronic myeloid leukemia (CML) who have a sustained deep molecular response using tyrosine kinase inhibitors (TKIs) can safely attempt to stop their use. As these medications are very costly, this change in treatment protocols may result in large savings. Objective: To estimate future savings from attempting to stop TKI use among patients with CML who have deep molecular response. Design, Setting, and Participants: A microsimulation model was developed for this decision analytical modeling study to estimate costs for US adults moving from using a TKI, to attempting discontinuation and then reinitiating TKI therapy, if clinically appropriate. Estimates were calculated for US patients who currently have CML and simulated newly diagnosed cohorts of patients over the next 30 years. Exposure: Attempting to stop using a TKI. Main Outcomes and Measures: Estimated savings after attempted discontinuation of TKI use. Results: A simulated population of individuals with CML in 2018 and future populations were created using estimates from the SEER*Explorer website. The median age at diagnosis was 66 years for men and 65 years for women. Between 2022 and 2052, the savings associated with eligible patients attempting discontinuation of TKI therapy was estimated at more than $30 billion among those currently diagnosed and over $15 billion among those who will develop CML in the future, for a total savings of over $54 billion by 2052 for drug treatment and polymerase chain reaction testing. The estimate is conservative as it does not account for complications and other health care-associated costs for patients continuing TKI therapy. Conclusions and Relevance: The findings of this decision analytical modeling study of patients with CML suggest that attempting discontinuation of TKI therapy could save over $54 billion during the next 30 years. Further education for patients and physicians is needed to safely increase the number of patients who can successfully attain treatment-free remission.

Melanoma and CLL co-occurrence and survival: role of KC history.

BACKGROUND: Survival following melanoma and chronic lymphocytic leukemia (CLL) have both been individually associated with previous history of non-melanoma skin cancers (specifically keratinocyte carcinomas [KC]). Furthermore, melanoma and CLL have been reported to occur within the same patients. The survival experience of patients with both cancers is understudied, and the role of history of KC is unknown. Additional research is needed to tease apart the independent associations between KC and CLL survival, KC and melanoma survival, and the co-occurrence of all three cancers. METHODS: A retrospective cohort study was conducted among patients who were diagnosed with melanoma and/or CLL at a comprehensive cancer center between 2008 and 2020. Multivariable Cox regression models were used to examine the association between history of KC and survival following melanoma and/or CLL with careful consideration of calendar year of diagnosis, treatment regimens and other risk factors. A nested case-control study comparing patients with both CLL and melanoma to those with only CLL or only melanoma was conducted to compare blood parameters across the three groups. RESULTS: A time-dependent association was observed between history of KC and favorable melanoma survival within 4 years following diagnosis and poorer survival post 7 years after melanoma diagnosis. History of KC was not significantly associated with survival following the diagnosis of CLL, after adjustment for clinical factors including historical/concurrent melanoma. Patients with co-occurring melanoma and CLL tended to be diagnosed with melanoma first and had elevated blood parameters including white blood cell and lymphocyte counts as compared with patients who were diagnosed with only melanoma. CONCLUSIONS: History of KC was an independent predictor of survival following melanoma but not of CLL. Additional studies are needed to determine if blood parameters obtained at the time of melanoma diagnosis could be used as a cost-effective way to identify those at high risk of asymptomatic CLL for the promotion of earlier CLL diagnosis.

Results of VOICE: a global survey of disease-specific knowledge and perspectives of real-world patients with CLL.

The Virtual Opinions poll Independent Centered on CLL patients' Experience (VOICE) evaluated patients' knowledge about chronic lymphocytic leukemia (CLL), their perspectives on diagnosis and treatment, and their unmet needs. Clinicians and patient advocacy group representatives developed and distributed the survey from March through December 2022 in 12 countries, and 377 patients with ≥1 line of previous CLL treatment responded from Europe, Latin America, the United States, Australia, Egypt, and Turkey. A majority of them (90%; 336/374) relied on their physicians for information regarding CLL and treatment. If at high risk, respondents prefer oral medications to intravenous (78%; 232/296), fixed duration treatment over treatment until progression (69%; 185/270), outpatient over inpatient treatments (91%; 257/283). Over three-fourths of respondents (78%; 286/368) wanted to be involved in treatment decisions, but a minority actually participated (44%; 138/313). COVID-19 vaccinations were widely available (97%; 273/281), but one-fifth (19%; 63/331) were unaware that CLL increases vulnerability to infections. Most patients' physicians explained their treatment options (84%; 297/355), and 90% (271/301) understood their treatment. Notably, >10% would continue treatment normally if they experienced cardiac problems or arrhythmias, whereas 23% would consider stopping treatment if they developed skin cancer. Treatment-associated side effects affected 27% to 43% of patients. These results in a global patient population highlight gaps in patients' knowledge of risk groups, their susceptibility to infections including COVID, and the side effects of common treatments. Such knowledge can guide the appropriate targeting of patient education initiatives by clinicians, advocates, and policymakers.

Sézary syndrome originates from heavily mutated hematopoietic progenitors.

The pathogenesis of cutaneous T-cell lymphoma (CTCL) remains unclear. Using single-cell RNA or T-cell receptor (TCR) sequencing of 32 619 CD3+CD4+ and CD26+/CD7+ and 29 932 CD3+CD4+ and CD26-/CD7- lymphocytes from the peripheral blood of 7 patients with CTCL, coupled to single-cell ATAC-sequencing of 26,411 CD3+CD4+ and CD26+/CD7+ and 33 841 CD3+CD4+ and CD26-/CD7- lymphocytes, we show that tumor cells in Sézary syndrome and mycosis fungoides (MF) exhibit different phenotypes and trajectories of differentiation. When compared to MF, Sézary cells exhibit narrower repertoires of TCRs and exhibit clonal enrichment. Surprisingly, we identified ≥200 mutations in hematopoietic stem cells from multiple patients with Sézary syndrome. Mutations in key oncogenes were also present in peripheral Sézary cells, which also showed the hallmarks of recent thymic egression. Together our data suggest that CTCL arises from mutated lymphocyte progenitors that acquire TCRs in the thymus, which complete their malignant transformation in the periphery.

Outcomes of CD19-Directed Chimeric Antigen Receptor T Cell Therapy for Transformed Nonfollicular Lymphoma.

CD19-directed chimeric antigen receptor (CAR) T cell (CAR-T) therapy with axicabtagene ciloleucel (axi-cel) or tisagenlecleucel (tisa-cel) are approved for the treatment of relapsed or refractory large B cell lymphoma (LBCL), including de novo diffuse LBCL (DLBCL), primary mediastinal B cell lymphoma (PMBCL), and transformed follicular lymphoma (tFL). Transformed nonfollicular lymphomas (tNFLs), including transformed marginal zone lymphoma (tMZL) and transformed chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) were not included in their respective pivotal studies. This study was conducted to evaluate the outcomes of axi-cel and tisa-cel in tNFL patients, including those who received ibrutinib concomitantly through apheresis, lymphodepletion, and CAR-T infusion. This single-center retrospective study included all patients with tCLL/SLL, tMZL, tFL, and DLBCL/PMBCL treated with CAR-T therapy outside of a clinical trial setting from November 2017 to May 2021 at Moffitt Cancer Center, Tampa, Florida. We analyzed and compared outcomes in patients with tCLL/SLL or tMZL and patients with DLBCL/tFL. The study included 134 patients who received a total of 136 CAR-T treatments (111 with axi-cel and 25 with tisa-cel). Ninety patients had de novo DLBCL/PMBCL, 23 had tFL, and 21 had tNFL (12 with tMZL and 9 with tCLL/SLL). The overall response and complete response rates were 66.7% and 55.6%, respectively, for tCLL/SLL and 92.9% and 71.4% for tMZL. The overall response and complete response rates were not different between tNFL and DLBCL/tFL (P = .92 and .81, respectively). At a median follow-up of 21.3 months, the median progression-free survival (PFS) for tCLL/SLL was 5.4 months (95% confidence interval [CI], .8 month to not assessable [NA]); for tMZL, the median PFS was not reached (NR) (95% CI, 2.3 months to NA); and for DLBCL/tFL, the median PFS was 14.3 months (95% CI, 5.6 months to NA) (P = .58). The estimated 1-year PFS rate was 29.6% (95% CI, 5.2% to 60.7%) for tCLL/SLL, 50.0% (95% CI, 22.9% to 72.2%) for tMZL, 42.7% (95% CI, 22.4% to 61.6%) for tNFL, and 53.0% (95% CI, 42.3% to 62.5%) for DLBCL/tFL. The median overall survival was NR (95% CI, 9.2 months to NA) for tCLL/SLL, 27.1 months (95% CI, 8.5 months to NA) for tMZL, and NR (95% CI, 17.4 months to NA) for DLBCL/tFL (P = .79). Compared to the DLBCL/tFL cohort, tNFL patients were more likely to develop immune effector cell-associated neurologic syndrome (ICANS) and to receive tocilizumab (P = .04 and .01, respectively, after controlling for CAR-T product) and with a possibly higher incidence of grade ≥3 cytokine release syndrome (CRS) (P = .07). Two patients in the tNFL cohort died of treatment-related toxicity after receiving axi-cel. Six tNFL patients received ibrutinib concurrently with tisa-cel, with 1 case of grade ≥3 CRS/ICANS that rapidly resolved and no other severe toxicities. Our case series supports the use of CD19 CAR-T therapy in relapsed/refractory tCLL/SLL and tMZL. The concurrent use of ibrutinib and tisa-cel in tNFL was associated with manageable toxicity in tNFL.

Risks and outcomes of hospitalizations in patients with chronic lymphocytic leukemia admitted with immune thrombocytopenia: an analysis of the National Inpatient Sample Database.

Immune thrombocytopenia (ITP) is a known autoimmune complication of chronic lymphocytic leukemia (CLL). Currently, there is limited data regarding the risk CLL confers on hospitalization outcomes in patients admitted with ITP.The National Inpatient Sample (NIS) database was queried using the International Classification of Diseases (ICD) codes to identify hospitalizations for ITP and then subclassified the data into hospitalizations with and without CLL. A multivariate logistic regression was designed to account for patient characteristics and comorbidities. The primary outcome was all-cause mortality. Secondary outcomes included major bleeding, gastrointestinal bleeding, intracranial bleeding, and the need for platelet transfusions, intravenous immunoglobulin, and splenectomy. Among 662,171 cases of ITP between 2005 and 2019, 15,672 had concurrent CLL. CLL patients were significantly older and had more comorbidities compared to patients without CLL. Multivariate analysis revealed CLL patients with ITP had a risk of all-cause mortality (odds ratio: 1.28, 95% CI: 1.19-1.37; p < 0.01). CLL patients also had a higher risk of complications, second-line ITP treatments, blood transfusions, and bleeding, with the exception of intracranial hemorrhage. Our study suggests CLL is an independent risk factor for increased morbidity and mortality among hospitalized patients with ITP. Prospective studies are needed to determine if refractoriness to conventional treatments for ITP can account these results.

Molecular response in newly diagnosed chronic-phase chronic myeloid leukemia: prediction modeling and pathway analysis.

Tyrosine kinase inhibitor therapy revolutionized chronic myeloid leukemia treatment and showed how targeted therapy and molecular monitoring could be used to substantially improve survival outcomes. We used chronic myeloid leukemia as a model to understand a critical question: why do some patients have an excellent response to therapy, while others have a poor response? We studied gene expression in whole blood samples from 112 patients from a large phase III randomized trial (clinicaltrials gov. Identifier: NCT00471497), dichotomizing cases into good responders (BCR::ABL1 ≤10% on the International Scale by 3 and 6 months and ≤0.1% by 12 months) and poor responders (failure to meet these criteria). Predictive models based on gene expression demonstrated the best performance (area under the curve =0.76, standard deviation =0.07). All of the top 20 pathways overexpressed in good responders involved immune regulation, a finding validated in an independent data set. This study emphasizes the importance of pretreatment adaptive immune response in treatment efficacy and suggests biological pathways that can be targeted to improve response.

The role of Th17 cells in chronic lymphocytic leukemia: friend or foe?

T helper 17 (Th17) cells have a prominent role in autoimmune diseases. In contrast, the nature of these cells in cancer is controversial, with either pro- or antitumorigenic activities depending on various cancer settings. Chronic lymphocytic leukemia (CLL), a B-cell malignancy, is characterized by an imbalance in T-cell immune responses that contributes to disease progression and increased mortality. Many clinical reports indicate an increase in Th17 cells and/or interleukin 17 serum cytokine levels in patients with CLL compared with healthy individuals, which correlates with various prognostic markers and significant changes in the tumor microenvironment. The exact mechanisms by which Th17 cells might contribute to CLL progression remain poorly investigated. In this review, we provide an updated presentation of the clinical information related to the significance of Th17 cells in CLL and their interaction with the complex leukemic microenvironment, including various mediators, immune cells, and nonimmune cells. We also address the available data regarding the effects of CLL-targeted therapies on Th17 cells and the potential of using these cells in adoptive cell therapies. Having a sound understanding of the role played by Th17 cells in CLL is crucial for designing novel therapies that can achieve immune homeostasis and maximize clinical benefits.

Pneumococcal Conjugate Vaccine Does Not Induce Humoral Response When Administrated Within the Six Months After CD19 CAR T-Cell Therapy.

CD19 targeted chimeric antigen receptor-modified T cell therapy (CAR-T) leads to B cell aplasia and low serum immunoglobulin levels. Long-lived CD19-negative plasma cells may persist through the therapy and generate antibodies. There is a paucity of data describing how CAR-T impacts the persistence of antibodies against vaccine-related antigens and the degree to which CAR-T recipients may respond to vaccines. We characterized the effect of CAR-T on pneumococcal immunoglobulin G (IgG) titers and determine whether pneumococcal conjugate vaccine (PCV13) administered after CAR-T develops long-term humoral protection against pneumococcus. A retrospective chart review was performed to identify CAR-T recipients who had serum pneumococcal IgG titers drawn before (baseline) or at days +90, +180, +270, +360, or +540 after CAR-T. We then determined whether they received PCV13 vaccination at these timepoints. IgG concentration ≥1.3 µg/mL was considered protective for that serotype, and patients with ≥6/11 tested vaccine-specific serotypes meeting this threshold were deemed to have humoral protection against pneumococcus. Absolute pneumococcal IgG titers and the proportion of patients with humoral protection, stratified by serotype, and vaccination status were compared by paired nonparametric t-tests. Absolute counts for lymphocyte, CD4 T-cell, and CD19 cell and total IgG level, along with the rate of invasive pneumococcal infections, were measured at these timepoints. A total of 148 CAR-T recipients with pneumococcal IgG titers measured for at least one of the defined time points were identified. At baseline, 25% (19/76) patients with evaluable pneumococcal IgG titers met the definition of humoral protection. Among 44 patients with paired pneumococcal IgG titers at baseline and day+90, absolute IgG titers of all serotypes decreased (geometric mean = 0.41 and 0.32 µg/mL, respectively; P < .001). Thirteen patients were vaccinated following the titer blood draw at day+90 and had paired pneumococcal IgG titers at day+90 and day180. Absolute IgG titers of all vaccine specific serotypes in these vaccinated patients decreased from day+90 to day+180 (geometric mean = 0.36 and 0.29 µg/mL, respectively; P = .03). The proportion of patients meeting the criteria of humoral protection remained the same at day+180 despite vaccination at day+90. The results were similar among 8 patients vaccinated at day+180, as well as 7 patients consecutively vaccinated at day+90 and day+180 with corresponding pneumococcal IgG titers. When all vaccine-specific pneumococcal IgG titers were pooled together by timepoint regardless of vaccination status, the proportion of patients with humoral protection decreased until day+540. Some patients developed humoral protection after vaccination at day+360, maintained seroprotective IgG titers from baseline, or developed protection after receiving intravenous immunoglobulin treatment secondary to recurrent infections. Our study demonstrated that few large B cell lymphoma patients had humoral protection against pneumococcus at baseline, and existing IgG titers decreased after CAR-T. PCV13 vaccination at day+90 or day+180 after CAR-T did not increase humoral protection against pneumococcus. Only at day+540 was there evidence of humoral protection against pneumococcus in a modest proportion of patients. Clinical trials are needed to determine the optimal timing of vaccination, before or after CAR-T, to develop protective immunity against Streptococcus pneumoniae infections.

Ponatinib after failure of second-generation tyrosine kinase inhibitor in resistant chronic-phase chronic myeloid leukemia.

Ponatinib, the only third-generation pan-BCR::ABL1 inhibitor with activity against all known BCR::ABL1 mutations including T315I, has demonstrated deep and durable responses in patients with chronic-phase chronic myeloid leukemia (CP-CML) resistant to prior second-generation (2G) TKI treatment. We present efficacy and safety outcomes from the Ponatinib Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ ALL) and CML Evaluation (PACE) and Optimizing Ponatinib Treatment in CP-CML (OPTIC) trials for this patient population. PACE (NCT01207440) evaluated ponatinib 45 mg/day in CML patients with resistance to prior TKI or T315I. In OPTIC (NCT02467270), patients with CP-CML and resistance to ≥2 prior TKIs or T315I receiving 45 or 30 mg/day reduced their doses to 15 mg/day upon achieving ≤1% BCR::ABL1IS or received 15 mg/day continuously. Efficacy and safety outcomes from patients with CP-CML treated with ≥1 2G TKI (PACE, n = 257) and OPTIC (n = 93), 45-mg starting dose cohort, were analyzed for BCR::ABL1IS response rates, overall survival (OS), progression-free survival (PFS), and safety. By 24 months, the percentages of patients with ≤1% BCR::ABL1IS response, PFS, and OS were 46%, 68%, and 85%, respectively, in PACE and 57%, 80%, and 91%, respectively, in OPTIC. Serious treatment-emergent adverse events and serious treatment-emergent arterial occlusive event rates were 63% and 18% in PACE and 34% and 4% in OPTIC. Ponatinib shows high response rates and robust survival outcomes in patients whose disease failed prior to 2G TKIs, including patients with T315I mutation. The response-based dosing in OPTIC led to improved safety and similar efficacy outcomes compared with PACE.

Loss of AID exacerbates the malignant progression of CLL.

Activation-induced cytidine deaminase (AID) has been implicated as both a positive and a negative factor in the progression of B cell chronic lymphocytic leukemia (CLL), but the role that it plays in the development and progression of this disease is still unclear. We generated an AID knockout CLL mouse model, AID-/-/Eµ-TCL1, and found that these mice die significantly earlier than their AID-proficient counterparts. AID-deficient CLL cells exhibit a higher ER stress response compared to Eµ-TCL1 controls, particularly through activation of the IRE1/XBP1s pathway. The increased production of secretory IgM in AID-deficient CLL cells contributes to their elevated expression levels of XBP1s, while secretory IgM-deficient CLL cells express less XBP1s. This increase in XBP1s in turn leads AID-deficient CLL cells to exhibit higher levels of B cell receptor signaling, supporting leukemic growth and survival. Further, AID-/-/Eµ-TCL1 CLL cells downregulate the tumor suppressive SMAD1/S1PR2 pathway and have altered homing to non-lymphoid organs. Notably, CLL cells from patients with IgHV-unmutated disease express higher levels of XBP1s mRNA compared to those from patients with IgHV-mutated CLL. Our studies thus reveal novel mechanisms by which the loss of AID leads to worsened CLL and may explain why unmutated CLL is more aggressive than mutated CLL.

Regulatory T cells (Tregs) in lymphoid malignancies and the impact of novel therapies.

Regulatory T cells (Tregs) are responsible for maintaining immune homeostasis by controlling immune responses. They can be characterized by concomitant expression of FoxP3, CD25 and inhibitory receptors such as PD-1 and CTLA-4. Tregs are key players in preventing autoimmunity and are dysregulated in cancer, where they facilitate tumor immune escape. B-cell lymphoid malignancies are a group of diseases with heterogenous molecular characteristics and clinical course. Treg levels are increased in patients with B-cell lymphoid malignancies and correlate with clinical outcomes. In this review, we discuss studies investigating Treg immunobiology in B-cell lymphoid malignancies, focusing on clinical correlations, mechanisms of accumulation, phenotype, and function. Overarching trends suggest that Tregs can be induced directly by tumor cells and recruited to the tumor microenvironment where they suppress antitumor immunity to facilitate disease progression. Further, we highlight studies showing that Tregs can be modulated by novel therapeutic agents such as immune checkpoint blockade and targeted therapies. Treg disruption by novel therapeutics may beneficially restore immune competence but has been associated with occurrence of adverse events. Strategies to achieve balance between these two outcomes will be paramount in the future to improve therapeutic efficacy and safety.

Treatment outcomes with purine nucleoside analog alone or with rituximab for hairy cell leukemia at first relapse.

INTRODUCTION: Frontline treatment of hairy cell leukemia (HCL) with a single course of the purine nucleoside analog (PNA) produces a high rate of complete remission (CR) with prolonged durations. At the time of relapse, although treatment guidelines recommend re-treatment with a PNA alone or in combination with rituximab (R), practice patterns vary and data supporting each approach are limited. METHODS: We conducted a multisite outcomes analysis of patients treated for HCL between 1995 and 2018 at six US medical centers. All patients were treated with frontline PNA and subsequently required treatment with a PNA alone (PNA) or with R (+R). RESULTS: Of the 88 patients analyzed, 56 (63.6%) received second-line PNA and 22 (36.4%) received a PNA + R. Baseline characteristics of both groups were similar. There was no difference in median PFS [67 months (95% CI 43.8 non-reached (NR)) vs. 65 months (95% CI 60-NR)] or 5-year OS [98% (95% CI 0.94-1) vs. 94% (95% CI 0.83-1), p = .104] in the PNA versus PNA + R cohorts, respectively. CONCLUSION: To our knowledge, this is the largest study evaluating the role of R in treatment of relapsed HCL and suggests that there is no advantage to the addition of R to PNA therapy at the time of first re-treatment.

Retrospective analysis of arterial occlusive events in the PACE trial by an independent adjudication committee.

BACKGROUND: The phase 2 PACE (Ponatinib Ph+ ALL and CML Evaluation) trial of ponatinib showed robust long-term benefit in relapsed Philadelphia chromosome-positive (Ph+) leukemia; arterial occlusive events (AOEs) occurred in ≥ 25% of patients based on investigator reporting. However, AOE rates vary depending on the definitions and reporting approach used. METHODS: To better understand clinically relevant AOEs with ponatinib, an independent cardiovascular adjudication committee reviewed 5-year AOE data from the PACE trial according to a charter-defined process and standardized event definitions. RESULTS: A total of 449 patients with chronic myeloid leukemia (CML) or Ph+ acute lymphoblastic leukemia (ALL) received ponatinib (median age 59 y; 47% female; 93% ≥ 2 prior tyrosine kinase inhibitors (TKIs); median follow-up, 37.3 months). The adjudicated AOE rate (17%) was lower than the non-adjudicated rate (i.e., rate before adjudication; 25%). The only adjudicated AOE in > 2% of patients was peripheral arterial occlusive disease (4%). Exposure-adjusted incidence of newly occurring adjudicated AOEs decreased over time. Patients with multiple baseline cardiovascular risk factors had higher adjudicated AOE rates than those without risk factors. CONCLUSIONS: This independent adjudication study identified lower AOE rates than previously reported, suggesting earlier overestimation that may inaccurately reflect AOE risk with ponatinib. This trial was registered under ClinicalTrials.gov identifier NCT01207440 on September 23, 2010 ( https://clinicaltrials.gov/ct2/show/NCT01207440 ).