Pembrolizumab and decitabine for refractory or relapsed acute myeloid leukemia

Background

The powerful ‘graft versus leukemia’ effect thought partly responsible for the therapeutic effect of allogeneic hematopoietic cell transplantation in acute myeloid leukemia (AML) provides rationale for investigation of immune-based therapies in this high-risk blood cancer. There is considerable preclinical evidence for potential synergy between PD-1 immune checkpoint blockade and the hypomethylating agents already commonly used for this disease.

Methods

We report here the results of 17 H-0026 (PD-AML, NCT02996474), an investigator sponsored, single-institution, single-arm open-label 10-subject pilot study to test the feasibility of the first-in-human combination of pembrolizumab and decitabine in adult patients with refractory or relapsed AML (R-AML).

Results

In this cohort of previously treated patients, this novel combination of anti-PD-1 and hypomethylating therapy was feasible and associated with a best response of stable disease or better in 6 of 10 patients. Considerable immunological changes were identified using T cell receptor β sequencing as well as single-cell immunophenotypic and RNA expression analyses on sorted CD3+ T cells in patients who developed immune-related adverse events (irAEs) during treatment. Clonal T cell expansions occurred at irAE onset; single-cell sequencing demonstrated that these expanded clones were predominately CD8+ effector memory T cells with high cell surface PD-1 expression and transcriptional profiles indicative of activation and cytotoxicity. In contrast, no such distinctive immune changes were detectable in those experiencing a measurable antileukemic response during treatment.

Conclusion

Addition of pembrolizumab to 10-day decitabine therapy was clinically feasible in patients with R-AML, with immunological changes from PD-1 blockade observed in patients experiencing irAEs.

Fostamatinib for the Treatment of Hospitalized Adults With Coronavirus Disease 2019: A Randomized Trial

BACKGROUND

Coronavirus disease 2019 (COVID-19) requiring hospitalization is characterized by robust antibody production, dysregulated immune response, and immunothrombosis. Fostamatinib is a novel spleen tyrosine kinase inhibitor that we hypothesize will ameliorate Fc activation and attenuate harmful effects of the anti-COVID-19 immune response.

METHODS

We conducted a double-blind, randomized, placebo-controlled trial in hospitalized adults requiring oxygen with COVID-19 where patients receiving standard of care were randomized to receive fostamatinib or placebo. The primary outcome was serious adverse events by day 29.

RESULTS

A total of 59 patients underwent randomization (30 to fostamatinib and 29 to placebo). Serious adverse events occurred in 10.5% of patients in the fostamatinib group compared with 22% in placebo (P = .2). Three deaths occurred by day 29, all receiving placebo. The mean change in ordinal score at day 15 was greater in the fostamatinib group (-3.6 ± 0.3 vs -2.6 ± 0.4, P = .035) and the median length in the intensive care unit was 3 days in the fostamatinib group vs 7 days in placebo (P = .07). Differences in clinical improvement were most evident in patients with severe or critical disease (median days on oxygen, 10 vs 28, P = .027). There were trends toward more rapid reductions in C-reactive protein, D-dimer, fibrinogen, and ferritin levels in the fostamatinib group.

CONCLUSION

For COVID-19 requiring hospitalization, the addition of fostamatinib to standard of care was safe and patients were observed to have improved clinical outcomes compared with placebo. These results warrant further validation in larger confirmatory trials.

CLINICAL TRIALS REGISTRATION

Clinicaltrials.gov, NCT04579393.

Personalized Single-Cell Proteogenomics to Distinguish Acute Myeloid Leukemia from Non-Malignant Clonal Hematopoiesis

Genetic mutations associated with acute myeloid leukemia (AML) also occur in age-related clonal hematopoiesis, often in the same individual. This makes confident assignment of detected variants to malignancy challenging. The issue is particularly crucial for AML post-treatment measurable residual disease monitoring, where results can be discordant between genetic sequencing and flow cytometry. We show here, that it is possible to distinguish AML from clonal hematopoiesis and to resolve the immunophenotypic identity of clonal architecture. To achieve this, we first design patient-specific DNA probes based on patient's whole-genome sequencing, and then use them for patient-personalized single-cell DNA sequencing with simultaneous single-cell antibody-oligonucleotide sequencing. Examples illustrate AML arising from DNMT3A and TET2 mutated clones as well as independently. The ability to personalize single-cell proteogenomic assessment for individual patients based on leukemia-specific genomic features has implications for ongoing AML precision medicine efforts.

Risk-adapted, ofatumumab-based chemoimmunotherapy and consolidation in treatment-naïve chronic lymphocytic leukemia: a phase 2 study

High-risk cytogenetics and minimal residual disease (MRD) after chemoimmunotherapy (CIT) predict unfavorable outcome in chronic lymphocytic leukemia (CLL). This phase 2 study investigated risk-adapted CIT in treatment-naïve CLL (NCT01145209). Patients with high-risk cytogenetics received induction with fludarabine, cyclophosphamide, and ofatumumab. Those without high-risk cytogenetics received fludarabine and ofatumumab. After induction, MRD positive (MRD+) patients received 4 doses of ofatumumab consolidation. MRD negative (MRD-) patients had no intervention. Of 28 evaluable for response, all responded to induction and 10 (36%) achieved MRD-. Two-year progression-free survival (PFS) was 71.4% (CI₉₅, 56.5-90.3%). There was no significant difference in median PFS between the high-risk and the standard-risk groups. Ofatumumab consolidation didn't convert MRD + to MRD-. In the MRD + group, we saw selective loss of CD20 antigens during therapy. In conclusion, risk-adapted CIT is feasible in treatment-naïve CLL. Ofatumumab consolidation didn't improve depth of response in MRD + patients. Loss of targetable CD20 likely reduces efficacy of consolidation therapy.

Reconstitution of humoral immunity and decreased risk of infections in patients with chronic lymphocytic leukemia treated with Bruton tyrosine kinase inhibitors

Immune dysregulation in chronic lymphocytic leukemia (CLL) contributes to a high rate of infections and morbidity. The Bruton tyrosine kinase (BTK) inhibitors ibrutinib and acalabrutinib mark major breakthroughs in the treatment of CLL, however many patients require long-term therapy with these agents. Despite receiving effective therapy for CLL, patients on BTK inhibitors remain immunocompromised and at risk of infectious complications. We previously reported that treatment of CLL with ibrutinib leads to partial reconstitution of humoral immunity and fewer infections during the first two years of therapy. It is currently unclear whether the positive effects of ibrutinib on the immune system are sustained during long-term therapy. Acalabrutinib is a newer, more selective BTK inhibitor than ibrutinib; however a detailed evaluation of the immunologic impact of acalabrutinib therapy is lacking. Herein, utilizing two independent trials, we assessed the immunological effects and infectious risk of ibrutinib and acalabrutinib treatment in patients with CLL.

Abstract 3756: Highly multiplexed proteomic assessment of the human acute myeloid leukemia bone marrow microenvironment

Acute myeloid leukemia (AML) is a genetically heterogenous and often fatal cancer of the hematopoietic system. Even after achieving an initial complete remission, more than half of such AML patients experience clinical relapse due to the persistence of “minimal” residual disease (MRD). Ex-vivo studies have hypothesized that the interactions between residual leukemic cells and the local microenvironment in the bone marrow may play a key role in their survival and chemoresistance.

Therefore, we performed for the first time a global examination of the proteomic profile of the bone marrow microenvironment in AML patients using a highly multiplexed method based on the ability of slow off-rate modified aptamers (modified small single-stranded oligonucleotides) to bind target proteins with high specificity and affinity at slow dissociation rates. Ten relapsed/refractory adult AML patients and age-matched healthy subject controls were recruited, under an IRB-approved protocol, for research bone marrow aspirate (BMA) and blood serum collection. The supernatant resulting from centrifugation of BMA and serum samples were processed and analyzed on a SOMAscan™ hybridization microarray platform for the detection and quantification of 1,305 target proteins (Somalogic, CO). Data was corrected using Hybridization Control and Median Signal Normalization methods. Significant differences were found between AML and healthy donor bone marrow, such that 133 analytes were differentially expressed in the AML group (Wilcoxon rank sum test FDR p<0.05, fold change >1.5); 85 over-expressed and 48 under-expressed. In addition to proteins already known to be elevated in AML patients (eg: Erythropoietin, Thrombopoietin, Hepcidin and Ferritin) and dysregulation of pathways previously identified as disease relevant (eg: Arginase), we also discovered multiple statistically significant differences in levels of soluble proteins that are not currently known to be associated with AML pathogenesis or treatment. Comparative analysis between blood serum and bone marrow determined that 82 of the 133 candidates have differential expression that was specifically restricted to the bone marrow. The STRING database was queried for pathway analysis of enriched protein sets in the AML group and clustered analytes with molecular functions including cytokine activity (GO:0005125, n=11, p=1.93e-08), cytokine receptor binding (GO:0005126, n=12, p=3.17e-08) and signal transducer activity (GO:0004871, n=19, p=9.23e-05).

Using a high-throughput proteomic technology we have identified an AML bone marrow microenvironment-specific profile comprised of both proteins with known implications in leukemic pathogenesis and also several novel candidates from biologically plausible pathways that, once validated, may provide mechanistic insight and opportunity for therapeutic targeting.

Citation Format: Bogdan Popescu, Katherine Lindblad, Giovanna Fantoni, Gege Gui, Janet Valdez, Meghali Goswami, Christin DeStefano, Catherine Lai, Angélique Biancotto, Julián Candia, Foo Cheung, Julie Thompson, Laura W. Dillon, Christopher S. Hourigan. Highly multiplexed proteomic assessment of the human acute myeloid leukemia bone marrow microenvironment [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3756.

Activation of Th1 Immunity within the Tumor Microenvironment Is Associated with Clinical Response to Lenalidomide in Chronic Lymphocytic Leukemia

Immune stimulation contributes to lenalidomide's antitumor activity. Chronic lymphocytic leukemia (CLL) is characterized by the accumulation of mature, autoreactive B cells in secondary lymphoid tissues, blood, and bone marrow and progressive immune dysfunction. Previous studies in CLL indicated that lenalidomide can repair defective T cell function in vitro. Whether T cell activation is required for clinical response to lenalidomide remains unclear. In this study, we report changes in the immune microenvironment in patients with CLL treated with single-agent lenalidomide and associate the immunologic effects of lenalidomide with antitumor response. Within days of starting lenalidomide, T cells increased in the tumor microenvironment and showed Th1-type polarization. Gene expression profiling of pretreatment and on-treatment lymph node biopsy specimens revealed upregulation of IFN-γ and many of its target genes in response to lenalidomide. The IFN-γ-mediated Th1 response was limited to patients achieving a clinical response defined by a reduction in lymphadenopathy. Deep sequencing of TCR genes revealed decreasing diversity of the T cell repertoire and an expansion of select clonotypes in responders. To validate our observations, we stimulated T cells and CLL cells with lenalidomide in culture and detected lenalidomide-dependent increases in T cell proliferation. Taken together, our data demonstrate that lenalidomide induced Th1 immunity in the lymph node that is associated with clinical response.

Hair and Nail Changes During Long-term Therapy With Ibrutinib for Chronic Lymphocytic Leukemia

IMPORTANCE

Ibrutinib, a Bruton tyrosine kinase inhibitor, is a new targeted agent approved by the US Food and Drug Administration for the treatment of chronic lymphocytic leukemia (CLL), mantle cell lymphoma, and Waldenström macroglobulinemia. Ibrutinib is overall well tolerated but long-term treatment is required until disease progression or intolerable toxic effects occur. Little is known regarding its cutaneous adverse effects.

OBJECTIVE

To describe the hair and nail manifestations associated with the long-term use of ibrutinib for the treatment of CLL.

DESIGN, SETTING, AND PARTICIPANTS

Prospective study of 66 patients with CLL enrolled in a single-arm phase 2 clinical trial of ibrutinib for CLL between March 2014 and October 2015 at the National Institutes of Health.

MAIN OUTCOMES AND MEASURES

The primary outcome, nail and hair changes associated with ibrutinib therapy, was assessed by an 11-question survey. In addition, the severity of nail changes was determined from a 0 to 3 rating scale for both onychoschizia and onychorrhexis.

RESULTS

Among 66 patients (43 men and 23 women with ages ranging from 55 to 85 years), 44 (67%) reported brittle fingernails at a median of 6.5 (95% CI, 6-12) months after starting ibrutinib therapy. Fifteen patients (23%) developed brittle toenails after a median of 9 (95% CI, 6-15) months of ibrutinib therapy. Textural hair changes were reported in 17 patients (26%), at a median of 9 (95% CI, 6-12) months of ibrutinib treatment.

CONCLUSIONS AND RELEVANCE

Hair and nail abnormalities are commonly associated with ibrutinib and appear several months after initiating therapy. Ibrutinib inhibits Bruton tyrosine kinase by covalently binding to cysteine 481. Whether ibrutinib affects the hair and nails by binding and altering cysteine-rich proteins of hair and nails or by means of another mechanism remains unknown.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT01500733.

Eltrombopag Added to Standard Immunosuppression for Aplastic Anemia

BACKGROUND

Acquired aplastic anemia results from immune-mediated destruction of bone marrow. Immunosuppressive therapies are effective, but reduced numbers of residual stem cells may limit their efficacy. In patients with aplastic anemia that was refractory to immunosuppression, eltrombopag, a synthetic thrombopoietin-receptor agonist, led to clinically significant increases in blood counts in almost half the patients. We combined standard immunosuppressive therapy with eltrombopag in previously untreated patients with severe aplastic anemia.

METHODS

We enrolled 92 consecutive patients in a prospective phase 1-2 study of immunosuppressive therapy plus eltrombopag. The three consecutively enrolled cohorts differed with regard to the timing of initiation and the duration of the eltrombopag regimen (cohort 1 received eltrombopag from day 14 to 6 months, cohort 2 from day 14 to 3 months, and cohort 3 from day 1 to 6 months). The cohorts were analyzed separately. The primary outcome was complete hematologic response at 6 months. Secondary end points included overall response, survival, relapse, and clonal evolution to myeloid cancer.

RESULTS

The rate of complete response at 6 months was 33% in cohort 1, 26% in cohort 2, and 58% in cohort 3. The overall response rates at 6 months were 80%, 87%, and 94%, respectively. The complete and overall response rates in the combined cohorts were higher than in our historical cohort, in which the rate of complete response was 10% and the overall response rate was 66%. At a median follow-up of 2 years, the survival rate was 97%; one patient died during the study from a nonhematologic cause. Marked increases in bone marrow cellularity, CD34+ cell number, and frequency of early hematopoietic progenitors were noted. Rates of relapse and clonal evolution were similar to our historical experience. Severe rashes occurred in two patients, resulting in the early discontinuation of eltrombopag.

CONCLUSIONS

The addition of eltrombopag to immunosuppressive therapy was associated with markedly higher rates of hematologic response among patients with severe aplastic anemia than in a historical cohort. (Funded by the National Heart, Lung, and Blood Institute; ClinicalTrials.gov number, NCT01623167 .).

Disruption of in vivo Chronic Lymphocytic Leukemia Tumor-Microenvironment Interactions by Ibrutinib--Findings from an Investigator-Initiated Phase II Study

PURPOSE

Chronic lymphocytic leukemia (CLL) cells depend on microenvironmental interactions for proliferation and survival that are at least partially mediated through B-cell receptor (BCR) signaling. Ibrutinib, a Bruton tyrosine kinase inhibitor, disrupts BCR signaling and leads to the egress of tumor cells from the microenvironment. Although the on-target effects on CLL cells are well defined, the impact on the microenvironment is less well studied. We therefore sought to characterize the in vivo effects of ibrutinib on the tumor microenvironment.

EXPERIMENTAL DESIGN

Patients received single-agent ibrutinib on an investigator-initiated phase II trial. Serial blood and tissue samples were collected pretreatment and during treatment. Changes in cytokine levels, cellular subsets, and microenvironmental interactions were assessed.

RESULTS

Serum levels of key chemokines and inflammatory cytokines decreased significantly in patients on ibrutinib. Furthermore, ibrutinib treatment decreased circulating tumor cells and overall T-cell numbers. Most notably, a reduced frequency of the Th17 subset of CD4(+)T cells was observed concurrent with reduced expression of activation markers and PD-1 on T cells. Consistent with direct inhibition of T cells, ibrutinib inhibited Th17 differentiation of murine CD4(+)T cells in vitro Finally, in the bone marrow microenvironment, we found that ibrutinib disaggregated the interactions of macrophages and CLL cells, inhibited secretion of CXCL13, and decreased the chemoattraction of CLL cells.

CONCLUSIONS

In conjunction with inhibition of BCR signaling, these changes in the tumor microenvironment likely contribute to the antitumor activity of ibrutinib and may impact the efficacy of immunotherapeutic strategies in patients with CLL. See related commentary by Bachireddy and Wu, p. 1547.

Incidence and risk factors of bleeding-related adverse events in patients with chronic lymphocytic leukemia treated with ibrutinib

Ibrutinib is associated with bleeding-related adverse events of grade ≤ 2 in severity, and infrequently with grade ≥ 3 events. To investigate the mechanisms of bleeding and identify patients at risk, we prospectively assessed platelet function and coagulation factors in our investigator-initiated trial of single-agent ibrutinib for chronic lymphocytic leukemia. At a median follow-up of 24 months we recorded grade ≤ 2 bleeding-related adverse events in 55% of 85 patients. No grade ≥ 3 events occurred. Median time to event was 49 days. The cumulative incidence of an event plateaued by 6 months, suggesting that the risk of bleeding decreases with continued therapy. At baseline, von Willebrand factor and factor VIII levels were often high and normalized on treatment. Platelet function measured via the platelet function analyzer (PFA-100™) was impaired in 22 patients at baseline and in an additional 19 patients on ibrutinib (often transiently). Collagen and adenosine diphosphate induced platelet aggregation was tested using whole blood aggregometry. Compared to normal controls, response to both agonists was decreased in all patients with chronic lymphocytic leukemia, whether on ibrutinib or not. Compared to untreated chronic lymphocytic leukemia patients, response to collagen showed a mild further decrement on ibrutinib, while response to adenosine diphosphate improved. All parameters associated with a significantly increased risk of bleeding-related events were present at baseline, including prolonged epinephrine closure time (HR 2.74, P=0.012), lower levels of von Willebrand factor activity (HR 2.73, P=0.009) and factor VIII (HR 3.73, P=0.0004). In conclusion, both disease and treatment-related factors influence the risk of bleeding. Patients at greater risk for bleeding of grade ≤ 2 can be identified by clinical laboratory tests and counseled to avoid aspirin, non-steroidal anti-inflammatory drugs and fish oils. ClinicalTrials.gov identifier NCT01500733.

Interactions between Ibrutinib and Anti-CD20 Antibodies: Competing Effects on the Outcome of Combination Therapy

PURPOSE

Clinical trials of ibrutinib combined with anti-CD20 monoclonal antibodies (mAb) for chronic lymphocytic leukemia (CLL) report encouraging results. Paradoxically, in preclinical studies, in vitro ibrutinib was reported to decrease CD20 expression and inhibit cellular effector mechanisms. We therefore set out to investigate effects of in vivo ibrutinib treatment that could explain this paradox.

EXPERIMENTAL DESIGN

Patients received single-agent ibrutinib (420 mg daily) on an investigator-initiated phase II trial. Serial blood samples were collected pretreatment and during treatment for ex vivo functional assays to examine the effects on CLL cell susceptibility to anti-CD20 mAbs.

RESULTS

We demonstrate that CD20 expression on ibrutinib was rapidly and persistently downregulated (median reduction 74%, day 28, P < 0.001) compared with baseline. Concomitantly, CD20 mRNA was decreased concurrent with reduced NF-κB signaling. An NF-κB binding site in the promoter of MS4A1 (encoding CD20) and downregulation of CD20 by NF-κB inhibitors support a direct transcriptional effect. Ex vivo, tumor cells from patients on ibrutinib were less susceptible to anti-CD20 mAb-mediated complement-dependent cytotoxicity than pretreatment cells (median reduction 75%, P < 0.001); however, opsonization by the complement protein C3d, which targets cells for phagocytosis, was relatively maintained. Expression of decay-accelerating factor (CD55) decreased on ibrutinib, providing a likely mechanism for the preserved C3d opsonization. In addition, ibrutinib significantly inhibited trogocytosis, a major contributor to antigen loss and tumor escape during mAb therapy.

CONCLUSIONS

Our data indicate that ibrutinib promotes both positive and negative interactions with anti-CD20 mAbs, suggesting that successfully harnessing maximal antitumor effects of such combinations requires further investigation.

Ibrutinib-induced lymphocytosis in patients with chronic lymphocytic leukemia: correlative analyses from a phase II study

Ibrutinib and other targeted inhibitors of B-cell receptor signaling achieve impressive clinical results for patients with chronic lymphocytic leukemia (CLL). A treatment-induced rise in absolute lymphocyte count (ALC) has emerged as a class effect of kinase inhibitors in CLL and warrants further investigation. We here report correlative studies in 64 patients with CLL treated with ibrutinib. We quantified tumor burden in blood, lymph nodes, spleen, and bone marrow, assessed phenotypic changes of circulating cells, and measured whole blood viscosity. With just one dose of ibrutinib the average increase in ALC was 66%, and in over 40% of patients the ALC peaked within 24 hours of initiating treatment. Circulating CLL cells on day 2 showed increased Ki67 and CD38 expression, indicating an efflux of tumor cells from the tissue compartments into the blood. The kinetics and degree of the treatment-induced lymphocytosis was highly variable; interestingly in patients with a high baseline ALC the relative increase was mild and resolution rapid. After two cycles of treatment the disease burden in lymph node, bone marrow, and spleen decreased irrespective of the relative change in ALC. Whole blood viscosity was dependent on both ALC and hemoglobin. No adverse events were attributed to the lymphocytosis.

Abstract LB-141: Potent single agent activity of Ibrutinib (PCI-32765) in patients with chronic lymphocytic leukemia (CLL): clinical and translational results from an ongoing phase II study

Background: B-cell receptor (BCR) activation plays a pivotal role in the pathogenesis and for progression of CLL. Ibrutinib (PCI-32765), an irreversible inhibitor of Bruton's tyrosine kinase (BTK), can disrupt BCR signaling and has durable antitumor activity in CLL. We initiated a phase II single center trial to extend this experience and assess the impact of ibrutinib on tumor cells in vivo. Methods: Treatment naïve (TN) and relapsed/refractory (R/R) pts with CLL are treated with 420 mg ibrutinib daily. Pts are enrolled in 2 cohorts: 1) deletion (del) of chromosome 17p and 2) &gt;65yo and treated until disease progression. Response is evaluated at 6 months (mo) and every 6 mo thereafter. 17p del was assessed by FISH cytogenetics. Spleen volume on computed tomography (CT) scans was computed using a General Electric Advanced Workstation Server. Results: With a median follow-up of 9 mo we report on the first 53 patients: for del 17p n=29; 15 TN, 14 R/R; and for &gt;65yo n=24; 8 TN, 16 R/R. Estimated event free survival at 12 mo is 94%. Most adverse events were mild with non hematologic toxicities (regardless of causality) grade ≥3 in &lt;13% of pts. Two deaths on study were not treatment related. At 6 mo 95% of pts (n=44 evaluable) had a nodal response (median reduction in lymph node size of 73%) and 52% of pts had a partial response (PR) by IWCLL criteria. One pt had progressive disease (presumed Richter's transformation). All pts had a decrease in splenomegaly. The median reduction of splenic volume computed from CTs was 55% (30-1716 ml). Tumor infiltration in bone marrow biopsies (n=26), decreased by a median 82% as assessed by immunohistochemistry for CD79a and the median ALC decreased from 79 k/µl (0.5-402) to 32 k/µl (0.8-167) at 6 mo for a median reduction of 62%. We evaluated the in vivo effects of ibrutinib using blood and tissue samples collected pre and during ibrutinib treatment. On treatment expression of genes known to be induced by B-cell receptor (BCR) activation (Herishanu et al 2011) was significantly reduced in CLL cells in the peripheral blood (PB) in all pts (n=15; median reduction 57%; P&lt;.001). Consistent with inhibition of BCR signaling, we found concurrent reduction in PLCγ2 phosphorylation; a direct target of BTK. Patients also donated matched lymph node (LN) core biopsies pre-treatment and within the first 4 days on treatment. Ibrutinib inhibited BCR signaling in the LN (n=8, P=.004) to a similar degree as observed in the PB. Similarly, ibrutinib decreased expression of NF-κB target genes in PB and LN. In keeping with inhibition of BCR and NF-κB signaling surface markers of cellular activation such as CD38, CD69, and CD86 were significantly reduced by ibrutinib as measured by flow cytometry (P&lt;.02). Finally, ibrutinib significantly reduced tumor proliferation as determined by the percentage of PB CLL cells expressing Ki67 (median reduction of 80%; P&lt;.001). Conclusions: Ibrutinib as a single agent is well tolerated and highly effective in both TN and R/R pts achieving rapid disease control in blood, lymph nodes, spleen and bone marrow that is durable. Correlative studies on patient samples during ibrutinib treatment provide direct evidence for on target effects of ibrutinib in vivo demonstrating effective and sustained inhibition of BCR and NF-κB signaling in both PB and LNs. Ibrutinib deserves further investigation as targeted therapy for CLL.

We thank our patients for participation and donation of blood and tissue samples. Supported by the Intramural Research Program of NIH.

Citation Format: Adrian Wiestner, Sarah Herman, Rashida Mustafa, Janet Valdez, Jade Jones, Nakhle Saba, Andrew Lipsky, Diane C. Arthur, Gerald Marti, Francine Thomas, Irina Maric, Stefania Pittaluga, Xin Tian, Susan Soto, Georg Aue, Mohammed Z. Farooqui. Potent single agent activity of Ibrutinib (PCI-32765) in patients with chronic lymphocytic leukemia (CLL): clinical and translational results from an ongoing phase II study. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr LB-141. doi:10.1158/1538-7445.AM2013-LB-141

Lenalidomide-induced upregulation of CD80 on tumor cells correlates with T-cell activation, the rapid onset of a cytokine release syndrome and leukemic cell clearance in chronic lymphocytic leukemia

BACKGROUND

In chronic lymphocytic leukemia lenalidomide causes striking immune activation, possibly leading to clearance of tumor cells. We conducted this study to investigate the mechanism of action of lenalidomide and the basis for its unique toxicities in chronic lymphocytic leukemia.

DESIGN AND METHODS

Patients with relapsed chronic lymphocytic leukemia were treated with lenalidomide 20 mg (n=10) or 10 mg (n=8) daily for 3 weeks on a 6-week cycle. Correlative studies assessed expression of co-stimulatory molecules on tumor cells, T-cell activation, cytokine levels, and changes in lymphocyte subsets.

RESULTS

Lenalidomide upregulated the co-stimulatory molecule CD80 on chronic lymphocytic leukemia and mantle cell lymphoma cells but not on normal peripheral blood B cells in vitro. T-cell activation was apparent in chronic lymphocytic leukemia, weak in mantle cell lymphoma, but absent in normal peripheral blood mononuclear cells and correlated with the upregulation of CD80 on B cells. Strong CD80 upregulation and T-cell activation predicted more severe side effects, manifesting in 83% of patients as a cytokine release syndrome within 8-72 h after the first dose of lenalidomide. Serum levels of various cytokines, including tumor necrosis factor-alpha, increased during treatment. CD80 upregulation on tumor cells correlated with rapid clearance of leukemic cells from the peripheral blood. In contrast, neither the severity of the cytokine release syndrome nor the degree of T-cell activation in vitro correlated with clinical response.

CONCLUSIONS

Upregulation of CD80 on tumor cells and T-cell activation correlate with unique toxicities of lenalidomide in chronic lymphocytic leukemia. However, T-cell activation appears to be dispensable for the drug's anti-tumor effects. This provides a rationale for combinations of lenalidomide with fludarabine or alemtuzumab.

Helicobacter pylori infection: a new cause of anorexia in peritoneal dialysis patients

OBJECTIVE

Helicobacter pylori (HP) infection has frequently been found in dialysis patients. Chronic infections induce overproduction of pro-inflammatory substances. Inflammation has been associated with cachexia and anorexia. We explored the relationship between HP infection, anorexia, and malnutrition in peritoneal dialysis (PD) patients.

PATIENTS AND METHODS

The study included 48 clinically stable PD patients divided into four groups: HP+ with anorexia (group I, n = 12); HP+ without anorexia (group II, n = 4); HP- with anorexia (group III, n = 5); and HP- without anorexia (group IV, n = 27). Infection with HP was diagnosed by breath test. Anorexia was evaluated using a personal interview and an eating motivation scale (VAS). The VAS included five questions that are answered before and after eating. The questions concern desire to eat, hunger, feeling of fullness, prospective consumption, and palatability. Biochemical markers of nutrition and inflammation were also determined.

RESULTS

At baseline, group I showed lower scores for desire to eat, hunger sensation, prospective consumption, and palatability. They also showed lower lymphocyte counts, prealbumin, transferrin, serum albumin, normalized equivalent of protein-nitrogen appearance (nPNA), and residual renal function (RRF). In addition, the same group showed higher levels of C-reactive protein (CRP) and more sensation of fullness than the remaining groups. In the entire series, we found significant linear correlations between the following markers of nutrition and certain questions on the VAS: albumin with before-lunch desire to eat (r = 0.38, p < 0.05), and prealbumin with before-lunch hunger (r = 0.41, p < 0.05) and after-lunch hunger (r = -0.35, p < 0.05). Negative linear correlations were found between albumin and fullness before lunch (r = -0.45, p < 0.01), and between prealbumin and before-lunch desire to eat (r = -0.39, p < 0.05). Negative linear correlations were also seen between CRP and albumin (r = -0.35, p < 0.05) and between CRP and prealbumin (r = -0.36, p < 0.05). Similarly, CRP showed a negative correlation with before-lunch desire to eat (r = -0.38, p < 0.05) and afterlunch desire to eat (r = -0.45, p < 0.01). After HP eradication, group I showed a significant increase in markers of nutrition and in VAS scores for almost all questions. Simultaneously, they showed a decrease in CRP level. Significant differences were also found in lymphocyte count (1105 +/- 259.4 cells/mm3 vs 1330.8 +/- 316 cells/mm3, p < 0.05), nPNA (0.9 +/- 0.16 g/kg/day vs 1.07 +/- 0.3 g/kg/day, p < 0.05), prealbumin (26.7 +/- 6.5 mg/dL vs 33.9 +/- 56.6 mg/dL, p < 0.01), albumin (3.48 +/- 0.3 g/dL vs 3.67 +/- 0.35 g/dL, p < 0.05), CRP (1.16 +/- 1.14 mg/dL vs 0.88 +/- 1.2 mg/dL, p < 0.054), before-lunch desire to eat (56.6 +/- 6.8 vs 72.2 +/- 4, p < 0.001), after-lunch desire to eat (5.4 +/- 2.6 vs 12.3 +/- 2, p < 0.01), hunger before lunch (55.4 +/- 5.4 vs 73.1 +/- 4.6, p < 0.001), hunger after lunch (5.8 +/- 2.9 vs 11 +/- 4, p < 0.01), fullness before lunch (36.6 +/- 10.3 vs 18.7 +/- 8.8, p < 0.001), consumption after lunch (5 +/- 4.7 vs 17.5 +/- 18, p < 0.05), and palatability (61 +/- 5.3 vs 74.1 +/- 4.1, p < 0.001).

CONCLUSION

Infection with HP is associated with anorexia, inflammation, and malnutrition in PD patients. Eradication of HP significantly improves this syndrome. Residual renal function seem to have a protective effect on appetite preservation. The present study supports the hypothesis of the involvement of inflammation in the pathogenesis of malnutrition in PD patients.

Role of yoghurt in the prevention of colon cancer

The beneficial effect of yoghurt consumption on health and on the improvement of the mucosal immune system is well established, as is the diet-associated risk of colon cancer. In an experimental model in BALB/c mice we demonstrated that yoghurt added to the diet for 10 consecutive days, with the procedure repeated each 10 days for 6 months, inhibited the development of a colorectal carcinoma induced by 1,2 dimethylhydrazine (DMH). The immunoregulatory mechanisms involved in the inhibition of tumour growth by yoghurt were also examined in these studies. We determined B lymphocytes IgA(+) and IgG(+), as well as CD4(+) and CD8(+) T cells in the large intestine. We measured cellular apoptosis and the cytokines TNF-alpha, IFN-gamma and IL-10. An increase in the number of IgA(+) (P<0.01) was observed, but not in IgG(+) (P<0.01), or in the CD4(+) population (P<0.01) in the mice treated with DMH and yoghurt. While in the group with the carcinogen there was an enhancement in the IgG(+) B cells (P<0.01) and CD8(+) T cells (P<0.01). Yoghurt increased the number of apoptotic cells and induced IFN-gamma and TNF-alpha cytokine release, their production being regulated by an increase in IL-10 (P<0.001). We demonstrated that yoghurt may exert antitumour activity by a decrease in the inflammatory immune response mediated by IgA(+) increase, apoptosis induction and IL-10 release.

Expression of p21Waf1/Cip1 and cyclin D1 is increased in butyrate-resistant HeLa cells

Sodium butyrate induced cell cycle arrest in mammalian cells through an increase in p21Waf1/Cip1, although another study showed that this arrest is related to pRB signaling. We isolated variants of HeLa cells adapted to growth in 5 mm butyrate. One of these variants, clone 5.1, constitutively expressed elevated levels of p21Waf1/Cip1 when incubated in regular growth medium and in the presence of butyrate. Despite this elevated level of p21Waf1/Cip1, the cells continue to proliferate, albeit at a slower rate than parental HeLa cells. Western blot analyses showed that other cell cycle regulatory proteins were not up-regulated to compensate for the elevated expression of p21Waf1/Cip1. However, cyclin D1 was down-regulated by butyrate in HeLa cells but not in clone 5.1. We conclude that continued expression of cyclin D1 allowed clone 5.1 to grow in the presence of butyrate and elevated levels of p21Waf1/Cip1.

Synthesis and antiparasitic activity of 2-(trifluoromethyl)-benzimidazole derivatives

2-(Trifluoromethyl)benzimidazole derivatives substituted at the 1-, 5-, and 6-positions have been synthesized and in vitro tested against the protozoa Giardia lamblia, Entamnoeha histolytica. and the helminth Trichinella spiralis. Results indicate that all the compounds tested are more active as antiprotozoal agents than Albendazole and Metronidazole. One compound (20) was as active as Albendazole against T. spiralis. These compounds were also tested for their effect on tubulin polymerization and none inhibited tubulin polymerization.

Penetrating eye injury in war

The percentage of penetrating eye injuries in war has increased significantly in this century compared with the total number of combat injuries. With the increasing use of fragmentation weapons and possibly laser weapons on the battle-field in the future, the rate of eye injuries may exceed the 13% of the total military injuries found in Operations Desert Storm/Shield. During the Iran-Iraq War (1980-1988), eye injuries revealed that retained foreign bodies and posterior segment injuries have an improved prognosis in future military ophthalmic surgery as a result of modern diagnostic and treatment modalities. Compared with the increasing penetrating eye injuries on the battlefield, advances in ophthalmic surgery are insignificant. Eye armor, such as visors that flip up and down and protect the eyes from laser injury, needs to be developed. Similar eye protection is being developed in civilian sportswear. Penetrating eye injury in the civilian sector is becoming much closer to the military model and is now comparable for several reasons.

Increased prevalence of cysticercosis and taeniasis among professional fried pork vendors and the general population of a village in the Peruvian highlands. Cysticercosis Working Group in Peru

Two different populations in Saylla, a Peruvian village near Cusco, known for chicharrones, a local pork dish, were surveyed by serology and stool examination to determine the prevalence and epidemiologic characteristics of Taenia solium infection. Group I (n=43), the chicharroneros, were members of families professionally devoted to the making and selling of chicharrones, and Group II (n=102) was a sample of the general population of the same village. Unlike people in Group I, general villagers only occasionally prepare or sell this food product, and then only to their neighbors or relatives. The prevalence of taeniasis was extremely high (8.6%) for the chicharroneros and 3% for the general villagers. Seroprevalence for cysticercosis by immunoblot was similarly high in both groups (23.3% and 23.8%, respectively). Being female, older than 30, and having daily contact with pork were factors strongly associated with a positive serologic result for cysticercosis in the chicharroneros, whereas males were more frequently seropositive in the general villagers group. Antibody reaction to more antigen bands in immunoblots and neurologic symptoms were more common among the chicharroneros. Also, in the general villagers group, seroprevalence increased with each exposure factor, ranging from 9.4% in individuals who did not raise pigs to 50% in the small subgroup that raised pigs, butchered their own animals, sold pork, and sold chicharrones, suggesting that these activities are related to increased risk for tapeworm or larval infection.

Chimeric purine transporters of Aspergillus nidulans define a domain critical for function and specificity conserved in bacterial, plant and metazoan homologues

In Aspergillus nidulans, purine uptake is mediated by three transporter proteins: UapA, UapC and AzgA. UapA and UapC have partially overlapping functions, are 62% identical and have nearly identical predicted topologies. Their structural similarity is associated with overlapping substrate specificities; UapA is a high-affinity, high-capacity specific xanthine/uric acid transporter. UapC is a low/moderate-capacity general purine transporter. We constructed and characterized UapA/UapC, UapC/UapA and UapA/UapC/UapA chimeric proteins and UapA point mutations. The region including residues 378-446 in UapA (336-404 in UapC) has been shown to be critical for purine recognition and transport. Within this region, we identified: (i) one amino acid residue (A404) important for transporter function but probably not for specificity and two residues (E412 and R414) important for UapA function and specificity; and (ii) a sequence, (F/Y/S)X(Q/E/P) NXGXXXXT(K/R/G), which is highly conserved in all homologues of nucleobase transporters from bacteria to man. The UapC/UapA series of chimeras behaves in a linear pattern and leads to an univocal assignment of functional domains while the analysis of the reciprocal and 'sandwich' chimeras revealed unexpected inter-domain interactions. cDNAs coding for transporters including the specificity region defined by these studies have been identified for the first time in the human and Caenorhabditis elegans databases.

[Ovum donation: a 3-year experience at the Gynecologic and Obstetric Center of Monterrey, Mexico]

OBJECTIVE

Evaluating the rate of pregnancies, neonates, implantation rate and kinds of donor in our program Assisted Reproduction with oocyte donation.

INTRODUCTION

The oocyte donation is the most important support in assisted reproduction because in patients with ovarian failure, offering the same opportunity to female without ovarian alterations to increase the rate of pregnancies.

MATERIAL AND METHOD

98 donor's procedures were included in host patients; 87 were FIV-TE and 11 GIFT between march to june 1997. The patients were divided in age group: 1) < 30 years, 2) 30 to 34 years, 3) 35 to 39 years, 4) > or = 40 years. The donors were divided in known (26) and unknown (72). The results were analysed.

RESULTS

48 pregnancies (55.17%) of the 87 FIV-TE-D group were obtained with 31 neonates The implantation rate was 17.5% to FIV-TE group and 13.8 to GIFT group, 44 (61.11%) pregnancies were from unknown donors group and 9 (34.61%) from known donors group.

CONCLUSIONS

Our results are similar to others international reports, we have observed a little and significative difference between pregnancy with oocytes from known donors and unknown donors; this is the principal motive to be selective in the suitable known donor.

Four distinct cyclin-dependent kinases phosphorylate histone H1 at all of its growth-related phosphorylation sites

In mammalian cells, up to six serines and threonines in histone H1 are phosphorylated in vivo in a cell cycle dependent manner that has long been linked with chromatin condensation. Growth-associated H1 kinases, now known as cyclin-dependent kinases (CDKs), are thought to be the enzymes responsible for this process. This paper describes the phosphorylation of histone H1 by four different purified CDKs. The four CDKs phosphorylate only the cell cycle specific phosphorylation sites of H1, indicating that they belong to the kinase class responsible for growth-related H1 phosphorylation in vivo. All four CDKs phosphorylate all of the interphase and mitotic-specific H1 sites. In addition to the (S/T)PXK consensus phosphorylation sites, these four CDKs also phosphorylate a mitotic-specific in vivo H1 phosphorylation site that lacks this sequence. There is no site selectivity among the growth-related phosphorylation sites by any of the four CDKs because all four CDKs phosphorylate all relevant sites. The results imply that the cell cycle dependent H1 phosphorylations observed in vivo must involve differential accessibility of H1 sites at different stages of the cell cycle.

Characterization of a putative helix-loop-helix motif in nucleotide excision repair endonuclease, XPG

Complementation group G of xeroderma pigmentosum (XPG) is one of the most rare and pathophysiologically heterogeneous forms of this inherited disease. XPG patients exhibit varying phenotypes, from having a very mild defect in DNA repair to being severely affected, and a few cases are also associated with the neurological degeneracy and growth retardation of Cockayne's syndrome. The XPG gene encodes a 134-kDa nuclear protein that is essential for the incision steps of nucleotide excision repair. XPG protein contains a putative helix-loop-helix (HLH) motif in the region that is most conserved among the members of structure-specific endonuclease family. To establish the functional significance of the HLH motif, we used several approaches, including theoretical modeling, functional complementation assay, structure-specific endonuclease assay, and DNA binding assay. A secondary structure of the motif was predicted by energy minimization and the Monte Carlo simulation and empirically proven using the circular dichroism to contain a high content of alpha-helix. When an XPG mutant lacking the HLH was overexpressed in UV135 cells, which have defects in the hamster homolog of XPG, the mutant gene failed to confer to the hamster cells the resistance to UV light. A recombinant XPG protein lacking the HLH motif was purified from insect cells and tested for a structure-specific endonuclease activity. The mutant protein failed to cleave the flap strand. A recombinant peptide containing the HLH (amino acids 758-871) was expressed in and purified from bacteria, tested for DNA binding activity, and found to bind to a DNA substrate with the flap structure. These results suggest that the HLH motif is required for the catalytic and DNA binding activities of XPG.

Active primary mirror support for the 2.1-m telescope at the San Pedro Mártir Observatory

We have designed and installed a new set of actuators for the suspension of the primary mirror of the 2.1-m telescope at San Pedro Mártir. This active optics system has allowed us to correct low-order aberrations identified by several wave-front analysis techniques.