S. de Vos

Ibrutinib versus ofatumumab in previously treated chronic lymphoid leukemia

BACKGROUND In patients with chronic lymphoid leukemia (CLL) or small lymphocytic lymphoma (SLL), a short duration of response to therapy or adverse cytogenetic abnormalities are associated with a poor outcome. We evaluated the efficacy of ibrutinib, a covalent inhibitor of Brutons tyrosine kinase, in patients at risk for a poor outcome. METHODS In this multicenter, open-label, phase 3 study, we randomly assigned 391 patients with relapsed or refractory CLL or SLL to receive daily ibrutinib or the anti-CD20 antibody ofatumumab. The primary end point was the duration of progression-free survival, with the duration of overall survival and the overall response rate as secondary end points. RESULTS At a median follow-up of 9.4 months, ibrutinib significantly improved progression-free survival; the median duration was not reached in the ibrutinib group (with a rate of progression-free survival of 88% at 6 months), as compared with a median of 8.1 months in the ofatumumab group (hazard ratio for progression or death in the ibrutinib group, 0.22; P<0.001). Ibrutinib also significantly improved overall survival (hazard ratio for death, 0.43; P=0.005). At 12 months, the overall survival rate was 90% in the ibrutinib group and 81% in the ofatumumab group. The overall response rate was significantly higher in the ibrutinib group than in the ofatumumab group (42.6% vs. 4.1%, P<0.001). An additional 20% of ibrutinib-treated patients had a partial response with lymphocytosis. Similar effects were observed regardless of whether patients had a chromosome 17p13.1 deletion or resistance to purine analogues. The most frequent nonhematologic adverse events were diarrhea, fatigue, pyrexia, and nausea in the ibrutinib group and fatigue, infusion-related reactions, and cough in the ofatumumab group. CONCLUSIONS Ibrutinib, as compared with ofatumumab, significantly improved progression-free survival, overall survival, and response rate among patients with previously treated CLL or SLL. (Funded by Pharmacyclics and Janssen; RESONATE ClinicalTrials.gov number, NCT01578707.).

Bortezomib in patients with relapsed or refractory mantle cell lymphoma: updated time-to-event analyses of the multicenter phase 2 PINNACLE study

BACKGROUND We previously reported results of the phase 2, multicenter PINNACLE study, which confirmed the substantial single-agent activity of bortezomib in patients with relapsed or refractory mantle cell lymphoma (MCL). MATERIALS AND METHODS We report updated time-to-event data, in all patients and by response to treatment, after extended follow-up (median 26.4 months). RESULTS Median time to progression (TTP) was 6.7 months. Median time to next therapy (TTNT) was 7.4 months. Median overall survival (OS) was 23.5 months. In responding patients, median TTP was 12.4 months, median duration of response (DOR) was 9.2 months, median TTNT was 14.3 months, and median OS was 35.4 months. Patients achieving complete response had heterogeneous disease characteristics; among these patients, median TTP and DOR were not reached, and median OS was 36.0 months. One-year survival rate was 69% overall and 91% in responding patients. Median OS from diagnosis was 61.1 months, after median follow-up of 63.7 months. Activity was seen in patients with refractory disease and patients relapsing following high-intensity treatment. Toxicity was generally manageable. CONCLUSIONS Single-agent bortezomib is associated with lengthy responses and notable survival in patients with relapsed or refractory MCL, with considerable TTP and TTNT in responding patients, suggesting substantial clinical benefit.

International Working Group consensus response evaluation criteria in lymphoma (RECIL 2017).

Abstract In recent years, the number of approved and investigational agents that can be safely administered for the treatment of lymphoma patients for a prolonged period of time has substantially increased. Many of these novel agents are evaluated in early-phase clinical trials in patients with a wide range of malignancies, including solid tumors and lymphoma. Furthermore, with the advances in genome sequencing, new “basket” clinical trial designs have emerged that select patients based on the presence of specific genetic alterations across different types of solid tumors and lymphoma. The standard response criteria currently in use for lymphoma are the Lugano Criteria which are based on [18F]2-fluoro-2-deoxy-D-glucose positron emission tomography or bidimensional tumor measurements on computerized tomography scans. These differ from the RECIST criteria used in solid tumors, which use unidimensional measurements. The RECIL group hypothesized that single-dimension measurement could be used to assess response to therapy in lymphoma patients, producing results similar to the standard criteria. We tested this hypothesis by analyzing 47 828 imaging measurements from 2983 individual adult and pediatric lymphoma patients enrolled on 10 multicenter clinical trials and developed new lymphoma response criteria (RECIL 2017). We demonstrate that assessment of tumor burden in lymphoma clinical trials can use the sum of longest diameters of a maximum of three target lesions. Furthermore, we introduced a new provisional category of a minor response. We also clarified response assessment in patients receiving novel immune therapy and targeted agents that generate unique imaging situations.

Distinct gene signature revealed in white blood cells, CD4 + and CD8 + T cells in (NZBx NZW) F1 lupus mice after tolerization with anti-DNA Ig peptide

Tolerizing mice polygenically predisposed to lupus-like disease (NZB/NZW F1 females) with a peptide mimicking anti-DNA IgG sequences containing MHC class I and class II T cell determinants (pConsensus, pCons) results in protection from full-blown disease attributable in part to the induction of CD4+CD25+Foxp3+ and CD8+Foxp3+ regulatory T cells. We compared 45 000 murine genes in total white blood cells (WBC), CD4+ T cells, and CD8+ T cells from splenocytes of (NZBxNZW) F1 lupus-prone mice tolerized with pCons vs untreated naïve mice and found two-fold or greater differential expression for 448 WBC, 174 CD4, and 60 CD8 genes. We identified differentially expressed genes that played roles in the immune response and apoptosis. Using real-time PCR, we validated differential expression of selected genes (IFI202B, Bcl2, Foxp3, Trp-53, CCR7 and IFNar1) in the CD8+T cell microarray and determined expression of selected highly upregulated genes in different immune cell subsets. We also determined Smads expression in different immune cell subsets, including CD4+ T cells and CD8+ T cells, to detect the effects of TGF-β, known to be the major cytokine that accounts for the suppressive capacity of CD8+ Treg in this system. Silencing of anti-apoptotic gene Bcl2 or interferon genes (IFI202b and IFNar1 in combination) in CD8+ T cells from tolerized mice did not affect the expression of the other selected genes. However, silencing of Foxp3 reduced expression of Foxp3, Ifi202b and PD1—all of which are involved in the suppressive capacity of CD8+ Treg in this model.

Identification of marker genes including RUNX3 ( AML2 ) that discriminate between different myeloproliferative neoplasms and normal individuals

Identification of marker genes including RUNX3 ( AML2 ) that discriminate between different myeloproliferative neoplasms and normal individuals

Venetoclax, bendamustine, and rituximab in patients with relapsed or refractory NHL: a phase Ib dose-finding study

Abstract Background Venetoclax is a selective, potent inhibitor of the anti-apoptotic B-cell leukemia/lymphoma-2 protein approved for treatment of chronic lymphocytic leukemia. We conducted a dose-finding study of venetoclax in combination with bendamustine–rituximab (BR) in patients with relapsed/refractory non-Hodgkin’s lymphoma (NHL). Patients and methods BR was given for six cycles at standard doses. Intermittent and continuous oral venetoclax administration was explored at 50–1200 mg daily doses. Co-primary objectives included safety, pharmacokinetics (PKs), maximum-tolerated dose (MTD), and recommended phase II dose (RP2D); secondary objective was preliminary efficacy. Results Sixty patients were enrolled: 32 with follicular lymphoma, 22 with diffuse large B-cell lymphoma, and 6 with marginal zone lymphoma. Nausea (70%), neutropenia (68%), diarrhea (55%), and thrombocytopenia (52%) were the most frequent adverse events (AEs). Most common grade 3/4 AEs were neutropenia (60%) and lymphopenia (38%). Serious AEs were reported in 24 patients; the most frequent were febrile neutropenia and disease progression (8% each). Five patients died from either disease progression (n = 4) or respiratory failure (n = 1). MTD was not reached; RP2D for venetoclax-BR combination was established as 800 mg daily continuously. Venetoclax PK exposure with and without BR was comparable. For all patients, overall response rate was 65%. Median duration of overall response, overall survival, and progression-free survival was 38.3 months [95% confidence interval (CI) 10.4–NR], not yet reached, and 10.7 months (95% CI 4.3–21.0), respectively. Conclusions This study established the safety profile of venetoclax in combination with BR, and results demonstrated tolerability and preliminary efficacy of the combination. Additional follow-up is needed to better determine the future role of BR plus venetoclax in the treatment of relapsed/refractory B-cell NHL. Trial registered Clinicaltrials.gov, NCT01594229.

Myeloid Differentiation Mediated Through New Potent Retinoids and Vitamin D3 Analogs

A focus of our investigations is to identify and study the biological activities and mechanism of action of novel vitamin D3 analogs and retinoids. Our model system is clonal proliferation and differentiation of hematopoietic cells in vitro. All-trans-retinoic acid and 9-cis-retinoic acid are naturally occurring ligands of the nuclear retinoic receptors (RARs). In concert with binding of ligand, these receptors form heterodimers with the retinoic × receptor (RXR), and transactivate RAR/RXR-responsive genes. Synthetic ligands to the RAR and RXR receptors have been developed that selectively bind and activate RAR/RXR (TTAB) and RXR/RXR dimers (SR11217). We investigated the effect of these ligands either alone or in combination on clonal growth and differentiation of leukemic promyelocitic cell line HL-60 and AML blasts from patients. TTAB inhibited 50% clonal growth at an effective dose (ED50) of 5 × 10−9 M for HL-60 and 8 × 10−8 M for AML blasts. SR11217 at 9 × 10−6 M was necessary to achieve an ED50 for HL-60 cells and an ED50 for AML blasts was not reached. Combinations of both ligands showed no synergistic effects. Parameters of differentiation were also examined. Results paralleled those of clonal growth, showing that ligands selective for RXR-homodimers have little effect on either induction of differentiation or inhibition of clonal growth of leukemic cells. The differentiative and antiproliferative effects of retinoids on hematopoietic cells are mainly induced through RAR/RXR heterodimers, and development of therapeutic analogs should focus on this category of retinoids.

Safety and efficacy of single-agent ibrutinib in patients with relapsed/refractory (R/R) marginal zone lymphoma (MZL): A multicenter, open-label, phase 2 study

1 (Th1) cells (Dubovsky, et al. Blood 2013). We describe the effect of ibr treatment on T‐cells and cytokines in pts in the DAWN study. Methods: This was a multicenter, single‐arm, phase 2 study of ibr in FL pts with ≥2 prior lines of therapy and progressive disease (PD) ≤ 12 months after CIT regimen. Pts received ibr (560 mg QD) on a 21‐day cycle until PD or toxicity. A protocol amendment allowed continued ibr treatment in clinically stable/improving pts with radiological evidence of PD (new lesion/increase ≥50%) to account for “pseudo‐PD”. The primary end point was the overall response rate (ORR) (complete response [CR] + partial response). Flow cytometry assessed T‐cell subsets in peripheral blood at baseline (C1D1) and at cycle 3 (C3D1) for 57 pts (14 responders, 43 nonresponders); cytokine and chemokine analyses were performed at C1D1 and at cycle 2 (C2D1) for 50 pts (21 responders, 29 nonresponders). Results: The DAWN study results have been presented (Gopal A, et al. ASH 2016); ibr achieved an ORR of 20.9% (CR rate, 10.9%). Flow cytometry analysis revealed CD4 + CD25 + CD127− Tregs were downregulated at C3D1 in responders (CR + PR, mean decrease 17 to 12.9% CD4, p = 0.02) but not in nonresponders (11.5 to 10.4% CD4, p = 0.17). There were no differences between responders and nonresponders in a large panel of inflammation‐related cytokines and chemokines at C1D1, confirmed by gene expression profiling in the tumor. After 21 days, Th1 cytokines interferon (IFN)‐γ and interleukin (IL)‐12 were increased in responders but decreased in nonresponders (p = 0.0025 and p = 0.035, respectively; Figure). The chemokines IFN‐γ‐induced protein 10 and monocyte‐chemotactic protein 3 were decreased in responders but increased in nonresponders (p = 0.022 and 0.016, respectively). Available data in pseudo‐PD pts showed a similar trend of decreased Tregs at C3D1 as responders, but the cytokines showed a similar trend as nonresponders. Conclusions: In ibr‐responding pts at early time points, Tregs were downregulated and Th1‐associated cytokines IFN‐γ and IL‐12 were increased. This shift inT‐cell population may be linked to the antitumor response; in nonresponders, these cytokines were decreased but Tregs were not. Chemokine changes suggest variation in chemoattraction. These data suggest that immunomodulatory effects of ibr could play a role in its antitumor activity in FL; combinations with other therapies may prove beneficial.

Induction of Immunity Against Leukemia

Great strides have been made in the chemotherapeutic treatment of acute lymphocytic leukemia (ALL) and moderate success has been made in treatment of acute myelogenous leukemia (AML). At this time, progress using chemotherapy has plateaued. Novel approaches to these diseases are required. Recent experiments have shown that several poorly immunogenic solid tumors can be recognized by MHC-class I restricted CD8+ cytotoxic T lymphocytes (CTL) if the tumors are engineered by genetransfer to produce one of several cytokines, including IL-2, IL-4, IL-6, IL-7, GM-CSF, TNF-α, IFN-α and -γ, or B7/BB1. The local secretion of lymphokines, critical for CTL activation, appears to bypass a deficient helper T-cell arm of the immune system. In addition, secretion of cytokines by the tumor cells stimulates the host immune system to identify and kill the untransduced parental cells upon subsequent reimplantation; and even of potential more importance, a rejection of established cancer can occur by inducing a systemic anticancer immune response by vaccination with cytokine transduced tumor cells. We studied two different murine myeloid leukemia models using WEHI3 and C1498 cell lines, transduced with a retroviral vector coding for human IL-7 (JZEN hIL/tk neo), resulting in cytokine production up to 13 ng/106 cells/24 hrs. NIH-3T3-fibroblasts, transduced with a vector coding for human IL-2 (G1Na CV hIL-2), producing up to 21 ng/106 cells/24 hrs, mixed with parental WEHI3 leukemia were used for vaccination-studies as well. Vaccination with IL-7 producing WEHI3 clones (weekly s.c. injections of 106 cells over a period of one month) resulted in a 43% survival of mice, subsequently challenged with a lethal dose of parental leukemic cells (5]104 i.v.). Vaccination with a mixture of IL-2 producing NIH-3T3-fibroblasts and parental WEHI3 cells resulted in a systemic protection of 60% of lethally challenged mice. The same experiments performed with the C1498-model showed a strong inherent immunogenicity of irradiated parental cells, as 4 out of 5 mice survived in this group. Surprisingly, all mice died in the group vaccinated with an IL-7 producing subclone. This illustrates that the process of selecting a high-cytokine producing subclone can result in clones that no longer represent the antigenic spectrum of the parental cells.