A subgroup of patients with severe COVID-19 suffers from progression to acute respiratory distress syndrome and multiorgan failure. These patients present with progressive hyperinflammation governed by proinflammatory cytokines. An interdisciplinary COVID-19 work flow was established to detect patients with imminent or full blown hyperinflammation. Using a newly developed COVID-19 Inflammation Score (CIS), patients were prospectively stratified for targeted inhibition of cytokine signalling by the Janus Kinase 1/2 inhibitor ruxolitinib (Rux). Patients were treated with efficacy/toxicity guided step up dosing up to 14 days. Retrospective analysis of CIS reduction and clinical outcome was performed. Out of 105 patients treated between March 30th and April 15th, 2020, 14 patients with a CIS ≥ 10 out of 16 points received Rux over a median of 9 days with a median cumulative dose of 135 mg. A total of 12/14 patients achieved significant reduction of CIS by ≥25% on day 7 with sustained clinical improvement in 11/14 patients without short term red flag warnings of Rux-induced toxicity. Rux treatment for COVID-19 in patients with hyperinflammation is shown to be safe with signals of efficacy in this pilot case series for CRS-intervention to prevent or overcome multiorgan failure. A multicenter phase-II clinical trial has been initiated (NCT04338958).

We have demonstrated that targeting lef-1 is a new and selective therapeutic approach in CLL. CGP049090 or PKF115-584 may be attractive compounds for CLL and other malignancies that deserve further (pre)clinical evaluation.

In a significant proportion of acute myeloid leukemia (AML) cases the canonical WNT pathway is upregulated and targeting the WNT/LEF1 signaling cascade in AML may be a promising approach to develop new treatments for this entity. Recently two compounds (CGP049090 and PFK115-584) have been identified, which specifically inhibit complexation of beta-catenin (CTNNB1) and lymphoid enhancer-binding factor 1 (LEF1) leading to transcriptional inactivation of LEF1 in colon carcinoma cell lines. To evaluate the effect of WNT inhibition utilizing theses compounds with regard to their effectivity in AML we treated the AML cell lines Kasumi-1 and HL-60, primary AML blasts and healthy peripheral blood mononuclear cells (PBMCs) with varying concentrations of both substances. Treatment with both compounds for 24 h resulted in a significant killing of AML cell lines and primary AML blasts with 50% effective concentration doses (EC(50)) within the submicromolar range. PBMCs were not significantly affected as indicated by EC(50)-values 100-fold higher than for AML cells. Cell kill was mediated by apoptosis as indicated by induction of caspases 3 and 7 and cleavage of poly(ADP-ribose) polymerase (PARP) upon treatment. Furthermore, we could show that both compounds substantially decrease expression of CTNNB1/LEF1 target genes c-myc, cyclin D1 and survivin, proofing the specificity of the substances. This was shown in both, AML cell lines and most of the tested primary samples. Our data demonstrate that targeting this pathway seems to be an innovative approach in the treatment of AML.

Purpose: Chronic lymphocytic leukemia (CLL) remains incurable despite advances in therapy. In this study, we characterize the effect of nicotinamide phosphoribosyltransferase (NAMPT) inhibition by FK866 in primary CLL cells from patients with various clinical prognostic markers.Experimental Design: CLL cells were treated with FK866 to assess viability by Annexin V/PI staining. Functional analysis of FK866 included time-and concentration-dependent evaluation of cellular NAD, ATP, mitochondrial membrane potential (MMP), reactive oxygen species (ROS), and apoptotic signaling. Chemosensitization potential by FK866 to fludarabine was also assessed. Prognostic markers were correlated with drug response.Results: FK866 induced CLL cell death by depleting cellular NAD content by day 1, followed by a drop in ATP on day 2. We observed loss of MMP, ROS increase, and induction of apoptotic signaling at day 3. Ontarget activity of FK866 was confirmed by NAD-mediated rescue of NAD and ATP loss, apoptotic signaling, and viability. The response to FK866 was independent of most prognostic markers. Higher doses were required with short lymphocyte doubling time and positive CD38 status, whereas CLL cells resistant to fludarabine in vitro and from patients with del17p13.1 were equally sensitive to FK866. FK866 did not upregulate the p53-target p21, nor did the p53 activator Nutlin improve FK866-mediated cell death. Furthermore, fludarabine and FK866 were synergistic at clinically relevant concentrations.Conclusions: NAMPT inhibition by FK866 may be a potential treatment for CLL, including patients with del17p13

No abstract

Purpose: There is evidence that vascular endothelial growth factor (VEGF) is a critical microenvironmental factor that exerts angiogenesis-independent effects on the survival of chronic lymphocytic leukemia (CLL) cells. Vatalanib and pazopanib are potent orally available VEGF receptor tyrosine kinase inhibitors. We investigated the efficacy and selectivity of both compounds in CLL cells, simulated potential combination with conventional cytostatics, and tested the effect of both substances on CLL-like tumor xenografts.Experimental Design: Primary CLL and normal peripheral blood cells were tested for viability after incubation with varying concentrations of both inhibitors. Further, phosphorylation status of VEGF receptor on treatment, caspase activation, and poly(ADP-ribose) polymerase cleavage were assessed. Combinations of each inhibitor with fludarabine, vincristine, and doxorubicin were analyzed for possible synergistic effects in vitro. For in vivo testing, mice grafted with the CLL-like cell line JVM-3 were treated orally with each inhibitor.Results: Vatalanib and pazopanib decreased phosphorylation of the VEGF receptor, along with induction of apoptosis in CLL cells in clinically achievable concentrations. Healthy B cells were only mildly affected. Immunoblots showed downregulation of the antiapoptotic proteins XIAP and MCL1, whereas poly(ADP-ribose) polymerase cleavage was increased. Combinations with conventional cytostatic agents resulted in synergistic effects. Treatment of xenografted mice with 100 mg/kg of body weight for 21 days resulted in tumor inhibition rates of 76% (vatalanib) and 77% (pazopanib). In two mice, a total tumor eradication could be observed. No gross systemic toxicity occurred.Conclusion: We conclude that VEGF inhibition is a promising new therapeutic approach in CLL. Vatalanib and pazopanib seem to be effective and safe candidates to be further evaluated for this purpose.

No abstract

Gene amplification, over-expression, and mutation of growth factors, or the receptors themselves, causes increased signaling through receptor kinases, which has been implicated in many human cancers and is associated with poor prognosis. Tumor growth has been shown to be decreased by interrupting this process of extensive growth factor-mediated signaling by directly targeting either the surface receptor or the ligand and thereby preventing cell survival and promoting apoptosis. Monoclonal antibodies have long been eyed as a potential new class of therapeutics targeting cancer and other diseases. Antibody-based therapy initially entered clinical practice when trastuzumab/Herceptin became the first clinically approved drug against an oncogene product as a well-established blocking reagent for tumors with hyperactivity of epidermal growth factor signaling pathways. In the first part of this review we explain basic terms related to the development of antibody-based drugs, give a brief historic perspective of the field, and also touch on topics such as the "humanization of antibodie" or creation of hybrid antibodies. The second part of the review gives an overview of the clinical usage of bispecific antibodies and antibodies "armed" with cytotoxic agents or enzymes. Further within this section, cancer-specific, site-specific, or signaling pathway-specific therapies are discussed in detail. Among other antibody-based therapeutic products, we discuss: Avastin (bevacizumab), CG76030, Theragyn (pemtumomab), daclizumab (Zenapax), TriAb, MDX-210, Herceptin (trastuzumab), panitumumab (ABX-EGF), mastuzimab (EMD-72000), Erbitux (certuximab, IMC225), Panorex (edrecolomab), STI571, CeaVac, Campath (alemtuizumab), Mylotarg (gemtuzumab, ozogamicin), and many others. The end of the review deliberates upon potential problems associated with cancer immunotherapy.