Fixed-duration venetoclax plus obinutuzumab improves quality of life and geriatric impairments in FCR-unfit patients with CLL.

Chronic lymphocytic leukemia (CLL)-related symptoms and morbidity related to the advanced age at diagnosis impairs the well-being of older adult patients. Therefore, it is essential to tailor treatment according to geriatric characteristics and aim for an improvement in health-related quality of life (HRQoL) as a primary treatment goal. In the HOVON139/GiVe trial, 12 cycles of fixed-duration venetoclax plus obinutuzumab (Ven-O) were shown to be effective and tolerable in FCR (fludarabine, cyclophosphamide, rituximab)-unfit patients with CLL (n = 67). However, prolonged venetoclax exposure as consolidation treatment led to increased toxicity with limited effect on minimal residual disease. To assess the impact of geriatric assessment on treatment outcomes and the patients' HRQoL, patient-reported outcomes (PROs), including function, depression, cognition, nutrition, physical performance, muscle parameters, comorbidities, and the European Organization for Research and Treatment of Cancer C30 and CLL17 questionnaires were assessed. At baseline, geriatric impairments were present in >90% of patients and ≥2 impairments present in 60% of patients predicted grade ≥3 nonhematological toxicity. During treatment, the number of geriatric impairments diminished significantly and clinically relevant improvements in HRQoL subscales were reached for global health status, physical functioning, role functioning, emotional functioning, fatigue, dyspnea, physical condition or fatigue, and worries or fears related to health and functioning. These improvements were comparable for patients receiving venetoclax consolidation and patients in whom treatment could mostly be discontinued. Collectively, frontline fixed-duration Ven-O improves overall PROs in older, unfit patients with CLL with and without geriatric impairments. This study was registered at EudraCT as 2015-004985-27 and the Netherlands Trial Register as NTR6043.

Venetoclax consolidation after fixed-duration venetoclax plus obinutuzumab for previously untreated chronic lymphocytic leukaemia (HOVON 139/GiVe): primary endpoint analysis of a multicentre, open-label, randomised, parallel-group, phase 2 trial.

BACKGROUND: Fixed-duration 12 cycles of venetoclax plus obinutuzumab is established as first-line treatment for patients with chronic lymphocytic leukaemia. We aimed to determine the activity and safety of 12 cycles of venetoclax consolidation after fixed-duration venetoclax plus obinutuzumab for previously untreated patients with chronic lymphocytic leukaemia who were unfit for fludarabine-based treatment, and whether this could be guided by minimal residual disease status. METHODS: We conducted an open-label, randomised, parallel-group, phase 2 trial (HOVON 139/GiVe) at 25 hospitals in the Netherlands. Eligible patients were aged 18 years or older with previously untreated chronic lymphocytic leukaemia, had an ECOG performance status of 0-2, and were unfit for fludarabine-based treatment. All patients received two debulking cycles of intravenous obinutuzumab (100 mg on day 1, 900 mg on day 2, and 1000 mg on days 8, 15, and day 1 of cycle two), followed by fixed-duration venetoclax plus obinutuzumab for 12 cycles (six cycles of intravenous obinutuzumab 1000 mg on day 1 and 12 during 28-day cycles of oral venetoclax, starting with a 5-week ramp-up and then 400 mg once daily until completion of cycle 12). Patients were then randomly assigned (1:1) by minimal residual disease status in peripheral blood, to receive either 12 cycles of venetoclax consolidation irrespective of minimal residual disease or venetoclax consolidation only if minimal residual disease was detected at randomisation. The primary endpoint was undetectable minimal residual disease in bone marrow and no progressive disease 3 months after end of consolidation treatment (or corresponding timepoint) by intention-to-treat. Safety was assessed in all patients who received at least one dose of any study drug. This is the primary endpoint analysis of this trial, which is ongoing and is registered with EudraCT (2015-004985-27). FINDINGS: Between Oct 28, 2016, and May 31, 2018, 70 patients were enrolled, of whom 67 (47 [70%] men and 20 [30%] women) received fixed-duration treatment and 62 were randomly assigned to receive 12 cycles of venetoclax consolidation (n=32) or minimal residual disease-guided venetoclax consolidation (n=30; one of whom was minimal residual disease positive at randomisation). Median follow-up was 35·2 months (IQR 31·5-41·3). 16 (50% [95% CI 32-68]) of 32 patients in the consolidation group and 16 (53% [34-72]) of 30 in the minimal residual disease-guided consolidation group met the primary endpoint of undetectable minimal residual disease in bone marrow and no progressive disease. 22 (69%) of 32 patients in the venetoclax consolidation group and 11 (37%) of 30 in the minimal residual disease-guided consolidation group had any adverse event (grade 2-4; mainly infections). The most common grade 3 or worse adverse events were infection (two [6%] of 32 patients in the consolidation group and one [3%] of 30 in the minimal residual disease-guided consolidation group) and neutropenia (two [6%] and two [7%]). There were no treatment-related deaths. INTERPRETATION: Consolidation with venetoclax 12-cycle treatment increases the duration of known side-effects and does not prevent the loss of minimal residual disease response and subsequent risk of disease relapse. FUNDING: F Hoffmann-La Roche.

Obinutuzumab pretreatment abrogates tumor lysis risk while maintaining undetectable MRD for venetoclax + obinutuzumab in CLL.

Early data on venetoclax-containing regimens for the treatment of chronic lymphocytic leukemia (CLL) show promising results with deep remissions, but are hampered by potential risk for tumor lysis syndrome (TLS). Whether optimal duration of venetoclax treatment can be guided by minimal residual disease (MRD) is currently unknown. To study whether TLS risk can be mitigated in an unfit population by introducing preinduction, and whether MRD-guided duration of venetoclax treatment is a feasible and efficacious approach, we performed the Dutch-Belgian Cooperative Trial Group for Hemato-oncology (HOVON) 139/GIVE trial. The study treatment consists of 4 treatment phases: preinduction (2 cycles obinutuzumab), induction I (6 cycles obinutuzumab and venetoclax), induction II (6 cycles venetoclax), and a randomization phase (group A: maintenance with 12 additional cycles of venetoclax irrespective of MRD; group B: MRD guided venetoclax maintenance with a maximum of 12 cycles). Here we report on a planned interim safety analysis as well as preliminary efficacy and MRD data of the first 30 patients enrolled. Downgrading of TLS risk after preinduction occurred in 25 patients: 3 from high to medium, 3 from high to low, and 19 from medium to low risk. No patient remained high risk. From these 30 patients, peripheral blood MRD data were obtained for 28 patients at the end of induction II (6 months after the last obinutuzumab dose), of whom 26 had undetectable MRD levels, and for 18 patients who reached the 3-month after-randomization point, of whom 16 had undetectable MRD levels. Obinutuzumab preinduction is tolerated well in these unfit patients and results in abrogating high TLS risk in all patients. Preliminary data indicate that efficacy is maintained with a high proportion of patients with undetectable MRD levels after combination treatment.

N-acetylcysteine reduces oxidative stress in sickle cell patients.

Oxidative stress is of importance in the pathophysiology of sickle cell disease (SCD). In this open label randomized pilot study the effects of oral N-acetylcysteine (NAC) on phosphatidylserine (PS) expression as marker of cellular oxidative damage (primary end point), and markers of hemolysis, coagulation and endothelial activation and NAC tolerability (secondary end points) were studied. Eleven consecutive patients (ten homozygous [HbSS] sickle cell patients, one HbSß(0)-thalassemia patient) were randomly assigned to treatment with either 1,200 or 2,400 mg NAC daily during 6 weeks. The data indicate an increment in whole blood glutathione levels and a decrease in erythrocyte outer membrane phosphatidylserine exposure, plasma levels of advanced glycation end-products (AGEs) and cell-free hemoglobin after 6 weeks of NAC treatment in both dose groups. One patient did not tolerate the 2,400 mg dose and continued with the 1,200 mg dose. During the study period, none of the patients experienced painful crises or other significant SCD or NAC related complications. These data indicate that N-acetylcysteine treatment of sickle cell patients may reduce SCD related oxidative stress.

Sickle cell patients are characterized by a reduced glycocalyx volume.

The glycocalyx is an important anti-inflammatory and anti-adhesive barrier at the luminal side of endothelial cells. Glycocalyx volume was significantly reduced in sickle cell patients (HbSS/HbSbeta(0)-thalassemia median 0.47L, IQR 0.27-0.66, HbSC/HbSbeta(+)-thalassemia 0.23L, 0.0-0.58) compared with controls (1 x 10(9)L, 0.52-1.77) (p=0.03). Reduced glycocalyx may be a new factor in the pathophysiology of sickle cell disease.

CD40 stimulation of B-cell chronic lymphocytic leukaemia cells enhances the anti-apoptotic profile, but also Bid expression and cells remain susceptible to autologous cytotoxic T-lymphocyte attack.

To enhance the poor antigen-presenting capacity of B-cell chronic lymphocytic leukaemia (B-CLL), CD40 triggering has been considered as an active immunotherapy. However, CD40 stimulation also has an anti-apoptotic effect and may further impair the dysregulated response of B-CLL to apoptotic stimuli. Therefore, we measured the expression of virtually all regulators of apoptosis before and after CD40 stimulation. These findings were correlated with sensitivity for chemotherapy- and death-receptor-induced apoptosis and T-cell-mediated killing. CD40 stimulation enhanced the constitutive anti-apoptotic profile of B-CLL cells by upregulation of Bcl-xL and Bfl-1 and downregulation of the BH3-only protein Harakiri. Unexpectedly, the BH3-only protein Bid was strongly induced. Functionally, CD40-stimulated B-CLL cells became resistant to drug-induced apoptosis and, despite upregulation of CD95 and Bid, were not sensitive to CD95L. In contrast, autologous T cell killing, triggered by loading CLL cells with viral (CMV) peptides, was very efficient both before and after CD40 stimulation. Upon CTL interaction, CLL targets underwent mitochondrial depolarization and caspase-3 activation. Thus, despite an increased anti-apoptotic profile, CD40 triggered B-CLL cells remain excellent targets for resident cytotoxic T cells. These data support therapeutic exploitation of CD40 stimulation in B-CLL, provided that a strong CTL component is induced.

Apoptosis via the B cell antigen receptor requires Bax translocation and involves mitochondrial depolarization, cytochrome C release, and caspase-9 activation.

Various routes to apoptosis can be active during B cell development. In a model system of mature B cells, differences in caspase-3 processing have suggested that antigen receptor (BCR)-mediated apoptosis may involve a zVAD-insensitive initiator protease(s). In search of the events leading to caspase-3 activation, we now establish that both CD95- and BCR-mediated apoptosis depend on Bax activation and cytochrome C (cytC) release. Nevertheless, the timing and caspase-dependence of mitochondrial membrane depolarization differed considerably after CD95- or BCR-triggering. To delineate events subsequent to cytC release, we compared apoptosis induced via BCR triggering and via direct mitochondrial depolarization by CCCP. In both cases, partial processing of caspase-3 was observed in the presence of zVAD. By expression in 293 cells we addressed the potential of candidate initiator caspases to function in the presence of zVAD, and found that caspase-9 efficiently processed caspase-3, while caspase-2 or -8 were inactive. Finally, retroviral expression of dominant-negative caspase-9 inhibited both CD95- and BCR-mediated apoptosis. In conclusion, we obtained no evidence for involvement of a BCR-specific protease. Instead, our data show for the first time that the BCR-signal causes Bax translocation, followed by mitochondrial depolarization, and cytC release. Subsequent caspase-9 activation can solely account for events further downstream.

Prevention of B cell antigen receptor-induced apoptosis by ligation of CD40 occurs downstream of cell cycle regulation.

Cross-linking of the B cell antigen receptor (BCR) on germinal center B cells can induce growth arrest and apoptosis, thereby eliminating potentially autoreactive B cells. Using the Burkitt lymphoma cell line Ramos as a model, we studied the commitment to apoptosis following growth arrest, as well as how triggering of CD40 or addition of tumor necrosis factor (TNF)-alpha can interfere to block cell death. Both BCR triggering and direct induction of growth arrest by sodium butyrate (n-But) caused hypophosphorylation of the retinoblastoma protein (pRb), followed by apoptosis. Interestingly, although CD40 ligation or TNF-alpha efficiently prevented BCR-induced and n-But-induced apoptosis, these co-stimuli did not inhibit, but rather augmented, growth arrest. Analysis of cell cycle regulators showed that each apoptotic and T(h) stimulus distinctly affected cyclins or cyclin-dependent kinase inhibitors, indicating that growth arrest can be uncoupled from apoptosis. BCR ligation and growth arrest activated the intrinsic or mitochondrial route of apoptosis. CD40 ligation and TNF-alpha prevented release of cytochrome c and activation of caspase-3, which could not be explained by effects on the expression of Bcl-2, Bcl-x(L) or Bax. Finally, the onset of BCR-induced apoptosis occurred after 10-12 h and addition of CD40 mAb or TNF-alpha at that point still prevented further execution of apoptosis. We conclude that in mature B cells apoptosis is not an obligatory event following growth arrest. Instead, commitment to apoptosis can be rapidly controlled by T cells via CD40 ligand and TNF-alpha, downstream of the pRb-regulated restriction point of the cell cycle, but prior to mitochondrial cytochrome c release.

Cell surface proteoglycan syndecan-1 mediates hepatocyte growth factor binding and promotes Met signaling in multiple myeloma.

Heparan sulfate proteoglycans (HSPGs) play a crucial role in growth regulation by assembling signaling complexes and presenting growth factors to their cognate receptors. Within the immune system, expression of the HSPG syndecan-1 (CD138) is characteristic of terminally differentiated B cells, ie, plasma cells, and their malignant counterpart, multiple myeloma (MM). This study explored the hypothesis that syndecan-1 might promote growth factor signaling and tumor growth in MM. For this purpose, the interaction was studied between syndecan-1 and hepatocyte growth factor (HGF), a putative paracrine and autocrine regulator of MM growth. The study demonstrates that syndecan-1 is capable of binding HGF and that this growth factor is indeed a potent stimulator of MM survival and proliferation. Importantly, the interaction of HGF with heparan sulfate moieties on syndecan-1 strongly promotes HGF-mediated signaling, resulting in enhanced activation of Met, the receptor tyrosine kinase for HGF. Moreover, HGF binding to syndecan-1 promotes activation of the phosphatidylinositol 3-kinase/protein kinase B and RAS/mitogen-activated protein kinase pathways, signaling routes that have been implicated in the regulation of cell survival and proliferation, respectively. These results identify syndecan-1 as a functional coreceptor for HGF that promotes HGF/Met signaling in MM cells, thus suggesting a novel function for syndecan-1 in MM tumorigenesis.