POS0400 MODULATION OF HUMAN EARLY B CELL DEVELOPMENT THROUGH TARGETED DEGRADATION OF IKAROS AND AIOLOS WITH IBERDOMIDE

Background

B differentiation in the bone marrow (BM) is impaired in patients carrying mutation in the IKFZ1 gene, coding for Ikaros a zinc-finger transcription factor. High Ikaros expression is on the contrary associated with systemic lupus erythematosus[1] and multiple myeloma[2]. Targeted treatment with iberdomide, a cereblon modulator which enhances degradation of Ikaros and Aiolos, is under clinical investigation in multiple myeloma patients and systemic lupus erythematosus. However, consequences of the treatment on human early B cell development remain elusive. Immature B cells develop in the BM from hematopoietic stem cells. An intricate network of transcription factors regulates the maturation process. Ikaros and Aiolos regulate gene expression during B cell development. As reported in mice, Ikaros is essential for the commitment to the lymphoid lineage and later, together with Aiolos, ensures the transition from pre-BII large to pre-BII small cells.

Objectives

Investigate the effect of iberdomide (CC-220) on human early B cell development simulated in vitro.

Methods

We tested the impact of iberdomide on short term culture of BM-derived lymphocytes and in a unique in vitro modeling of early B cell development starting from cord blood (CB)- CD34+ progenitors [3, 4]. We used multi-dimensional spectra flow cytometry (17-color pan-el) to dissect early B cell subpopulations.

Results

Iberdomide treatment led to enhanced degradation of Ikaros and Aiolos in both BM- and CB-derived cultures. Addition of iberdomide early (day 7) to the CB-derived culture impaired the specification to the lymphoid lineage and later also the commitment to the B cell lineage. These observations were confirmed by reduced E2A and PAX5 gene expression, respectively. Treatment with iberdomide on B cell precursors (pro- and pre-B cells, day 28 of culture) on one side it enhanced the proliferation of early progenitors resulting in increased amount of CD10+CD38+ lymphoid-committed cells. On the other side, it resulted in a accumulation of pre-B cells and inefficient development of immature B cells.

Conclusion

Iberdomide impairs the commitment to the lymphoid lineage by enhancing Ikaros’ degrada-tion. When targeting already committed B cells, iberdomide treatment undermines the transition of pre-BII large to pre-BII small cells due to increased Aiolos’ degradation, conse-quently impairing the development of immature B cells. Our data can instruct immunologi-cal monitoring of patients treated with iberdomide, and provide insights in the mechanisms of therapeutic efficacy.

References

[1]Rivellese, F., et al., Effects of targeting the transcription factors Ikaros and Aiolos on B cell activation and differentiation in systemic lupus erythematosus. Lupus Sci Med, 2021. 8(1).

[2]Thakurta, A., et al., Developing next generation immunomodulatory drugs and their combinations in multiple myeloma. Oncotarget, 2021. 12(15): p. 1555-1563.

[3]Kraus, H., et al., A Feeder-Free Differentiation System Identifies Autonomously Proliferating B Cell Precursors in Human Bone Marrow. The Journal of Immunology, 2014. 192(3): p. 1044-1054.

[4]Troilo, A., et al., Nonpermissive bone marrow environment impairs early B-cell development in common variable immunodeficiency. Blood, 2020. 135(17): p. 1452-1457.

Disclosure of Interests

Iga Janowska: None declared, Jakov Korzhenevich: None declared, Julian Staniek: None declared, Raquel Lorenzetti: None declared, Lukas Konstantinidis: None declared, Miriam Erlacher: None declared, Peter Schafer Employee of: BMS, Reinhard Voll: None declared, Jens Thiel Grant/research support from: BMS (former Cellgene), Nils Venhoff: None declared, Marta Rizzi Grant/research support from: BMS (former Cellgene)

POS0051 DIFFERENTIAL PHARMACODYNAMIC ALTERATIONS AFTER TREATMENT WITH ABATACEPT OR ADALIMUMAB IN MTX-INADEQUATE RESPONDER PATIENTS WITH EARLY RA: WHOLE BLOOD RNA-SEQ ANALYSIS OF THE EARLY AMPLE STUDY

Background

Despite advances in available novel pharmacologic agents for RA,1 the dearth of effective response predictors for specific therapies remains an unmet need. To inform clinical decision making, it is critical to define molecular signatures of these therapeutic agents by investigating their mechanisms of action (MoAs) and differential impacts on patients’ immune systems. Adalimumab and abatacept are biologic DMARDs with distinct MoAs used to treat RA. A better understanding of the differential pharmacodynamic (PD) changes of these 2 agents may provide guidance for the selection of treatment options.2 The Early AMPLE (Abatacept versus adaliMumab comParison in bioLogic-naïvE RA subjects with background MTX) study compared treatment with abatacept or adalimumab in a population of patients with early RA to explore differential PD effects; abatacept treatment resulted in numerically higher efficacy responses vs adalimumab after 24 weeks of treatment.3

Objectives

To investigate PD changes in response to treatment with abatacept or adalimumab, and to identify and differentiate the impact of each drug on modulation of immune cells at the molecular level.

Methods

The phase 4 Early AMPLE trial (NCT02557100) was a head-to-head comparison of treatment response to either abatacept or adalimumab in patients with early RA with an inadequate response to MTX, high anti-citrullinated protein antibody titers, and RF positivity, with or without shared epitope. Whole blood RNA sequencing (RNA-Seq) was conducted on samples collected from patients at different visits (day 1; weeks 4, 8, 16, 24, 28, 32, 40, 48). Differential gene expression analyses were performed using Limma-voom pipeline in R, adjusting for batch effect and sex. Over-representation tests were used to identify enriched Gene Ontology pathways. xCell, a gene signatures–based method learned from thousands of pure cell types, was applied for immune cell type deconvolution and enrichment analysis.

Results

PD and association analyses were performed for 14,540 protein-coding genes in 664 RNA-Seq samples (79 patients with RA at 9 visits). Baseline association analysis showed that 248 differentially expressed genes and 6 cell cycle–related pathways were significantly associated with baseline SDAI score. After treatment, gene-enrichment analysis demonstrated that twice as many genes and pathways were significantly altered in the adalimumab- vs abatacept-treated arm. Abatacept treatment decreased immune cell cycle gene expression while adalimumab treatment increased expression of these genes. The increases due to adalimumab were reversed after switching to abatacept (open-label period). Using gene signatures to identify key immune cell subsets (Figure 1), adalimumab therapy increased expression of genes defining several key immune cell types involved in RA disease development, including dendritic cells, T cells, and B cells; these effects were also reversed after switching to abatacept.

Conclusion

The differential gene expression seen after treatment with abatacept or adalimumab was noted in genes identified as correlating with RA disease activity. These findings may inform on the mechanism for the relatively greater clinical improvements seen with abatacept vs adalimumab in the Early AMPLE study. Abatacept treatment may selectively modulate genes that are relevant to disease pathology/progression, with the potential to restore the immune homeostasis dysregulated in RA. Our findings warrant further studies to investigate the potential positive correlation between RA-relevant PD effects and better therapeutic outcomes.

References

[1]Mysler E, et al. Open Access Rheumatol 2021;13:139–52.

[2]van Vollenhoven R. Nat Rev Rheumatol 2019;15:180–6.

[3]Rigby W, et al. Arthritis Res Ther 2021;23:245.

Acknowledgements

This study was sponsored by Bristol Myers Squibb. Medical writing and editorial assistance were provided by Joanna Wright, DPhil, of Caudex, and was funded by Bristol Myers Squibb.

Disclosure of Interests

Chun Wu Shareholder of: Bristol Myers Squibb, Employee of: Bristol Myers Squibb, Yicong Li Consultant of: Bristol Myers Squibb, Employee of: Parexel International, Neelanjana Ray Shareholder of: Bristol Myers Squibb, Employee of: Bristol Myers Squibb, Michael A Maldonado Employee of: Bristol Myers Squibb, Peter Schafer Shareholder of: Bristol Myers Squibb, Employee of: Bristol Myers Squibb, S. Louis Bridges Grant/research support from: Bristol Myers Squibb, William Rigby Consultant of: AbbVie, Bristol Myers Squibb, Grant/research support from: AbbVie, Bristol Myers Squibb, Vivian Bykerk Consultant of: Amgen, Bristol Myers Squibb, Genzyme Corporation, Gilead, Regeneron, UCB, Grant/research support from: Amgen, Bristol Myers Squibb, Genzyme Corporation, Pfizer, Regeneron, Sanofi Aventis, UCB, Jane Buckner Consultant of: Bristol Myers Squibb, Hotspot Therapeutics, Janssen, Grant/research support from: Current: Bristol Myers Squibb, GentiBio; past: Amgen, Janssen, Novo Nordisk, Pfizer, Jinqi Liu Shareholder of: Bristol Myers Squibb, Employee of: Bristol Myers Squibb

OP0132 EFFECT OF IBERDOMIDE ON CUTANEOUS MANIFESTATIONS IN SYSTEMIC LUPUS ERYTHEMATOSUS: RESULTS OF A 24-WEEK, PLACEBO-CONTROLLED, PHASE 2 STUDY

Background:

Iberdomide is a high-affinity cereblon ligand that promotes proteasomal degradation of Ikaros (IKZF1) and Aiolos (IKZF3), transcription factors involved in innate and adaptive immune cell development and homeostasis, and linked to the genetic risk for systemic lupus erythematosus (SLE). A phase 2, placebo-controlled study evaluated the efficacy and safety of iberdomide in patients (pts) with moderate to severe SLE.

Objectives:

To examine the effect of iberdomide on cutaneous manifestations in SLE pts.

Methods:

Adult autoantibody-positive SLE pts with a SLE Disease Activity Index 2000 (SLEDAI 2K) score ≥6 were randomized (2:2:1:2) to oral iberdomide (0.45, 0.3, 0.15 mg) or placebo once daily (QD) for 24 weeks while continuing standard background lupus medications. The Cutaneous Lupus Area and Severity Index Activity score (CLASI-A) was assessed every 4 weeks through week 24. As prespecified, exploratory analyses, change from baseline and the proportion of pts who achieved ≥50% reduction from baseline (CLASI-50) were evaluated for all pts, pts with baseline CLASI-A ≥8, and by cutaneous lupus subtypes (acute [ACLE], subacute [SCLE], chronic [CCLE]). CLASI-A outcomes were also evaluated post hoc for subgroups with high baseline expression of IKZF3 or the type 1 interferon (IFN) gene signatures in the blood.

Results:

Of 288 randomized pts, the mean and median (range) baseline CLASI-A scores were 6.9 and 5.0 (0-49), with 28% of pts having a score ≥8. 56% of pts had ACLE, 29% CCLE, and 16% SCLE. CLASI-50 responses were not significantly different comparing iberdomide to placebo in all pts and pts with baseline CLASI-A ≥8 at week 24, where high placebo response rates were observed (Table). Numerically greater mean improvement from baseline in CLASI-A scores in pts with baseline CLASI-A ≥8 was observed for iberdomide 0.45 mg vs placebo beginning at week 4, with continuous improvement through week 24. For pts with SCLE or CCLE, CLASI-50 response rates were significantly higher with iberdomide 0.45 mg vs placebo (P<0.04; Table). SCLE pts had significantly greater mean change and median percent improvement in CLASI-A from baseline with iberdomide 0.45 mg vs placebo at week 24 (P<0.03). Treatment differences in CLASI-A between iberdomide 0.45 mg and placebo were larger for SCLE and CCLE subgroups with high baseline IKZF3 or type 1 IFN gene signatures, with statistical significance achieved for SCLE pts but not CCLE pts (Figure).

Table 1.

CLASI-50 Response Rates by Subgroups at Week 24

0.15 mg QD0.3 mg QD0.45 mg QD(n=42)(n=82)(n=81)PlaceboSubgroup(n=83)0.15 mg QD vs Placebo0.3 mg QD vs Placebo0.45 mg QD vs Placebon/m (%)n/m (%)Str Diff in % (95% CI)P valuen/m (%)Str Diff in % (95% CI)P valuen/m (%)Str Diff in % (95% CI)P valueAll pts37/83 (44.6)19/42 (45.2)0.4 (-17.33, 18.55) P=0.96141/82 (50.0)5.3 (-9.93, 20.11) P=0.49945/81 (55.6)10.9 (-4.30, 25.51) P=0.163CLASI-A ≥810/20 (50.0)8/13 (61.5)15.9 (-17.42, 45.45) P=0.39913/24 (54.2)12.1 (-17.57, 39.97) P=0.45816/24 (66.7)15.1 (-15.51, 42.49) P=0.368ACLE23/50 (46.0)15/30 (50.0)4.8 (-17.22, 26.31) P=0.66220/43 (46.5)-3.3 (-22.95, 16.67) P=0.73817/38 (44.7)-3.0 (-23.20, 17.65) P=0.782SCLE9/17 (52.9)5/9 (55.6)2.6a (-33.04, 36.33) P=0.9663/9 (33.3)-6.6 (-38.98, 31.86) P>0.99911/12 (91.7)38.7a(4.54, 61.75) P=0.035CCLE5/18 (27.8)7/14 (50.0)22.2a (-10.51, 50.00) P=0.19810/23 (43.5)23.8 (-6.89, 48.88) P=0.12918/29 (62.1)34.1 (4.43, 56.16) P=0.029

CI, confidence interval; Str Diff, stratified difference.

aUnstratified difference.

Conclusion:

Iberdomide showed beneficial effects on skin manifestations in pts with SLE. Efficacy appears to be more pronounced in pts with SCLE and CCLE skin subtypes, and in pts with high IKZF3 or IFN gene expression signatures.

Δ, treatment difference of adjusted means; CCLE, chronic cutaneous lupus erythematosus; CLASI-A, Cutaneous Lupus Erythematosus Disease Area and Severity Index-activity score; IFN, interferon; SCLE, subacute cutaneous lupus erythematosus.

Acknowledgements:

This study was sponsored by Bristol Myers Squibb. Professional medical writing assistance was provided by Peloton Advantage, LLC, an OPEN Health company, and funded by Bristol Myers Squibb.

Disclosure of Interests:

Victoria Werth Consultant of: Bristol Myers Squibb, Grant/research support from: Bristol Myers Squibb, Joan Merrill Consultant of: UCB, GlaxoSmithKline, AbbVie, EMD Serono, Remegen, Celgene/Bristol Myers Squibb, AstraZeneca, Lilly, Immupharma, Amgen, Janssen, Resolve, Alpine, Aurinia, Astellas, Alexion, and Provention, Grant/research support from: GlaxoSmithKline and AstraZeneca, Richard Furie Consultant of: Bristol Myers Squibb, Grant/research support from: Bristol Myers Squibb, Thomas Dörner Consultant of: support for clinical studies and honoraria for scientific advice: AbbVie, Bristol Myers Squibb Company, Celgene, Eli Lilly, Janssen, Novartis, Roche, Employee of: Charite Universitätsmedizin, Berlin and DRFZ Berlin, Germany, Ronald van Vollenhoven Speakers bureau: UCB, AbbVie, Galapagos, Janssen, Pfizer, Paid instructor for: support for educational programs: Pfizer, Roche, Consultant of: AstraZeneca, Biogen, Biotest, Celgene, Gilead, Servier, UCB, AbbVie, Galapagos, Janssen, Pfizer, Grant/research support from: Bristol Myers Squibb, GlaxoSmithKline, Eli Lilly, UCB, Peter Lipsky Employee of: RILITE Foundation, Michael Weiswasser Shareholder of: Bristol Myers Squibb, Employee of: Bristol Myers Squibb, Shimon Korish Shareholder of: Bristol Myers Squibb, Employee of: Bristol Myers Squibb, Peter Schafer Shareholder of: Bristol Myers Squibb, Employee of: Bristol Myers Squibb, Mark Stern Shareholder of: Bristol Myers Squibb, Employee of: Bristol Myers Squibb, Zhaohui Liu Shareholder of: Bristol Myers Squibb, Employee of: Bristol Myers Squibb, Shaojun Tang Shareholder of: Bristol Myers Squibb, Employee of: Bristol Myers Squibb, Nikolay Delev Shareholder of: Bristol Myers Squibb, Employee of: Bristol Myers Squibb

AB0527 PHARMACOGENETICS AND PHARMACODYNAMICS OF RESPONSE TO APREMILAST IN A PHASE 3 CLINICAL STUDY IN SUBJECTS WITH ACTIVE BEHÇET’S DISEASE

Background:

Apremilast (APR), an oral phosphodiesterase 4 (PDE4) inhibitor, modulates inflammatory mediators1and has demonstrated efficacy in treating oral ulcers in a phase III Behçet’s syndrome study (BCT-002 [RELIEF]).2

Objectives:

To conduct an exploratory analysis of genetic polymorphisms, plasma biomarkers, and blood leukocytes with clinical response in RELIEF.

Methods:

Subjects with active Behçet’s disease (BD) were randomized (1:1) to APR 30 mg twice daily or placebo (PBO). The primary clinical efficacy endpoint was the area under the curve for the number of oral ulcers through Week 12 (AUCWk0-12). Among the 207 subjects enrolled, 140 provided consent for DNA genotyping, 116 for plasma biomarker testing, and 96 for leukocyte subset testing. Genotyping was performed on the Illumina Omni2.5 BeadChip (Covance Genomics Laboratory). TNF-α, IL-6, interferon-γ, and IL-17A levels were measured using Simoa Single Molecule Array; IL-8 and IL-23 were measured using the Human DiscoveryMAP multiplex panel (Myriad RBM). Th17, Treg, and CD3 T cells were counted using bisulfite-specific RT-PCR (Epiontis Gmbh). A rank ANCOVA model was used to estimate between-treatment differences (APR vs. PBO) in percent change from baseline for each biomarker/leukocyte subtype over the 12 weeks of treatment. Within each treatment group, the correlation of percent change from baseline at Week 12 in biomarker/leukocyte subtype with the primary efficacy endpoint AUCWk0-12was examined using a univariate regression model. A separate regression model was used to assess the interaction between treatment and the biomarker/leukocyte subtype clinical response.

Results:

Pharmacogenetic analysis of BD risk variants in HLA-B, IL-10, TLR2, ACE, TNF, GIMAP, PDGFRL, and UBAC2 + 55 genes associated with PDE4 biology yielded no candidate variants that were significantly associated with response to APR or PBO at a Bonferroni-correctedPvalue of 2 x 10−6. Clinical response to APR with respect to HLA-B51 yielded an odds ratio (OR) of 1.21 (95% CI, 0.53-2.75), indicating no significant relationship (Figure 1). Pharmacodynamic changes for IL-6, IL-3, IL-17A, IL-23, and TNF-α were not statistically significant. APR treatment was associated with a significant change in interferon-γ (mean: +107.4%; median: −19.2%) vs. PBO (mean: +78.8%; median: +7.9%) (P=0.0077). Using a univariate regression model, TNF-α showed strong positive correlation with AUCWk0-12in the APR group (r=0.90;P=0.0140); IL-8 had weak positive correlation with AUCWk0-12in the APR group (r=0.04;P=0.0333). A significant negative correlation was observed between the percent change from baseline in the number of Th17 cells and AUCWk0-12in the APR group (r=−0.79;P=0.0392) and a significant positive correlation was observed with the percent change from baseline in the number of Treg cells and AUCWk0-12in the PBO group (r=0.94;P=0.0182). Of all the biomarkers and leukocyte subtypes examined in a regression model using treatment as a factor, only Treg had a statistically significant treatment interaction (P=0.0069).

Conclusion:

Although there were no genetic predictors of clinical response to APR treatment, strong correlation was observed between the percent change from baseline in plasma TNF-α with AUCWk0-12in the APR group. A negative correlation was observed between percent change from baseline in Th17 cells and AUCWk0-12in the APR group and a positive association was observed between Treg cells and AUCW0-12in the PBO group.

References:

[1]Schafer P.Biochem Pharmacol. 2012; 83:1583-1590. 2. Hatemi G, et al. Presented at: ACR/ARHP Annual Meeting; November 8–13, 2019; Atlanta, GA. Presentation 0946.

Disclosure of Interests: :

Joseph Maranville Employee of: Celgene Corporation – employment at the time of study conduct, Irina Medvedeva Employee of: Celgene Corporation – employment at the time of study conduct, Robert Yang Employee of: Celgene Corporation – employment at the time of study conduct, Mindy Chen Employee of: Amgen Inc. – employment; Celgene Corporation – employment at the time of the conduct, Lorraine (Ruoying) Fang Employee of: Celgene Corporation – employment at the time of study conduct, Sandra Collazo Employee of: Amgen Inc. – employment; Celgene Corporation – employment at the time of the conduct, Shannon McCue Employee of: Amgen Inc. – employment; Celgene Corporation – employment at the time of the conduct, Peter Schafer Employee of: Bristol-Myers Squibb – employment; Celgene Corporation – employment at the time of study conduct

Dexamethasone synergizes with lenalidomide to inhibit multiple myeloma tumor growth, but reduces lenalidomide-induced immunomodulation of T and NK cell function

To determine the effect of dexamethasone on the antimyeloma effects of lenalidomide, we tested in vitro proliferation, tumor suppressor gene expression, caspase activity, cell cycling, and apoptosis levels in a series of multiple myeloma (MM) and plasma cell leukemia cell lines treated with lenalidomide and dexamethasone, alone or in combination. The effect of dexamethasone on the immunomodulatory activities of lenalidomide such as T cell and natural killer (NK) cell activation was measured via interleukin [IL]-2 production, and interferon-gamma and granzyme B production respectively. Lenalidomide inhibited proliferation in most cell lines tested, and this effect was enhanced by dexamethasone. This effect was observed in MM cells containing the high-risk cytogenetic abnormalities t(4;14), t(14;16), del17p, del13, and hypodiploidy. Mechanistically, lenalidomide plus dexamethasone synergistically induced expression of the tumor suppressor genes Egr1, Egr2, Egr3, p15, p21, and p27 in MM cell lines and MM patient cells. The combination activated caspases 3, 8, and 9; and induced cell cycle arrest and apoptosis. Lenalidomide alone increased T cell production of IL-2, and NK cell production of interferon-gamma and granzyme B. Notably, dexamethasone antagonized these immunostimulatory effects of lenalidomide in a dose-dependent manner. These data further elucidate the mechanism of action of lenalidomide and dexamethasone in MM, and suggest that use of low-dose dexamethasone with lenalidomide may retain the antiproliferative effect of lenalidomide while permitting greater immunomodulatory effects of this combination regimen.

Effect of lenalidomide on the antiproliferative effect of gemcitabine against pancreatic tumor cells and on immune-mediated pancreatic cancer cell death

e14635

Background: Lenalidomide is an immunomodulatory and anti-angiogenic agent that has demonstrated activity against a range of hematological malignancies. Despite evidence of direct anti-proliferative activity against hematological cells in vitro, there is no evidence of single agent direct activity against solid tumor cells in vitro. To take advantage of its known immune-enhancing properties alongside direct anti-tumor agents, lenalidomide is being advanced in solid tumor indications in combination with other agents. There are few data regarding the combination of lenalidomide and standard of care chemotherapeutic agents, such as gemcitabine. Methods: Here, we assess the effects of lenalidomide alone, and in combination with gemcitabine, on pancreatic cancer cell growth and survival, and the ability of lenalidomide to enhance the ability of human PBMC to kill allogeneic pancreatic tumor cells (BxPC3, PANC-1 and MiaPaCa) in a PBMC:tumor cell co-culture model. Results: Lenalidomide alone had no effect on the proliferation of pancreatic cancer cells (BxPC-3 and Panc-1) whereas gemcitabine had moderate anti-proliferative activity. With combination therapy there was clear synergistic enhancement of anti-proliferative activity in both cell lines and additive effects were observed in a BxPC-3 xenograft mouse model of pancreatic cancer. About 20% of tumor cells were sensitive to immune-mediated cell death and, for BxPC3, this was increased significantly in the presence of lenalidomide. Lenalidomide significantly and dose-dependently enhanced immune-mediated killing (both T and NK cells are required for tumor cell killing in this model). For PANC-1 and MiaPaCa, immune-mediated killing was also increased by lenalidomide, albeit non-significantly. Conclusions: These results suggest that, in addition to anti-angiogenic and other effects within the tumor microenvironment, lenalidomide may act as an immune adjuvant to enhance the recognition and apoptosis of tumor cells by host T and NK cells. These studies support the potential utility of lenalidomide in combination with chemotherapeutic agents, gemcitabine in particular, in the treatment of patients with solid tumors including pancreatic cancer.

[Table: see text]

Inhibition by lenalidomide of growth factor and hypoxia-induced signaling in endothelial and epithelial tumor cells, and effects within the tumor cell microenvironment

e14620

Background: Lenalidomide, an immunomodulatory and anti-angiogenic agent, has activity in many hematological malignancies. It has direct anti-proliferative activity in hematological cells but there is no evidence of direct activity in solid tumor cells. In solid tumors, lenalidomide is being advanced in combination with other agents to take advantage of its immune-enhancing properties in combination with direct anti-tumor agents. Lenalidomide studies in CLL and MM suggest that it may also attenuate pro-survival signals generated by interaction of stroma with the malignant cell itself. Lysophosphatidic acid (LPA) is a key pro-survival factor present at high levels within the ascites of ovarian cancer patients which confers increased tumor invasiveness and reduced survival. Hypoxia-induced factor (HIF)-1α is the key initiator of angiogenesis and tumor invasiveness. Methods: The effect of lenalidomide on growth factor-induced Akt phosphorylation was investigated in endothelial cells, NHL cells, and ovarian cancer cells in vitro. Ovarian cancer cell lines SKOV-3 and OVCAR-3 were treated with LPA and the effect of lenalidomide on invasiveness via enhanced p-Akt was investigated. The effect of lenalidomide on HIF-1α expression by endothelial cells and epithelial cells was also investigated. Results: Lenalidomide inhibited growth factor-induced Akt phosphorylation. Treatment of ovarian tumor cells with LPA increased tumor cell invasiveness via enhanced p-Akt. Lenalidomide strongly inhibited invasion and p-Akt (at S308 but not T473) in a dose-dependent manner. Hypoxic endothelial cells and epithelial tumor cells showed enhanced HIF-1α expression. Lenalidomide inhibited hypoxia-induced HIF-1α expression by endothelial cells and by epithelial tumor cells, including prostate, breast, pancreatic, renal and ovarian tumor cells. Conclusions: Lenalidomide may act within the tumor microenvironment to inhibit key signals of tumor cells survival, growth, and invasiveness. These studies support the potential utility of lenalidomide in combination with other agents in the treatment of patients with solid tumors.

[Table: see text]

Lenalidomide and pomalidomide strongly enhance tumor cell killing in vitro during antibody-dependent cellular cytotoxicity (ADCC) mediated by trastuzumab, cetuximab and rituximab

3023

Background: Potential mechanisms of action of lenalidomide and pomalidomide (CC-4047) include anti-angiogenic, anti- proliferative and immunomodulatory activities, e.g., enhancement of T cell and NK cell function. Both drugs appear to enhance T cell activation and Th1-type cytokines in cancer patients. Also, both drugs have been shown to enhance rituximab-mediated protection in a mouse lymphoma model. Methods: We have utilized an in vitro ADCC system to assess the ability of these drugs to enhance human NK cell function in response to the approved therapeutic antibodies trastuzumab, cetuximab and rituximab. Results: Pre-treatment of NK cells with either pomalidomide or lenalidomide greatly enhanced IFN-γ production by NK cells in response to IgG in the presence of either IL-2 or IL- 12. In a series of functional ADCC assays, Her2/neu overexpressing breast cancer cells (SKBR3 & MCF-7) pre-coated with trastuzumab, EGFR positive colorectal cancer cells (HCT-116) pre-coated with cetuximab and NHL cell lines (Namalwa, Farage & Raji) pre-coated with rituximab, were exposed to NK cells pre-treated with pomalidomide, lenalidomide or thalidomide. Both pomalidomide and lenalidomide synergistically increased (up to 6-fold) NK cell-mediated killing of antibody coated tumor cells in a dose-dependent manner. Thalidomide had no effect in this system. There was minimal tumor cell killing by antibody alone or in the absence of antibody. The presence of IL-2 or IL-12 was required to see enhanced killing by either drug. Enhanced ADCC was associated with increased signaling in NK cells, specifically with inhibition of the negative regulator SHIP-1. Other downstream effects on signaling pathways are also being investigated. Monocyte-mediated tumor cell ADCC was also enhanced by both drugs. Conclusions: We have shown that pomalidomide and lenalidomide (but not thalidomide) strongly enhance the ability of therapeutic antibodies to induce ADCC via NK cell/monocyte-mediated killing of tumor cells in vitro. These results provide a strong rationale for combination of either lenalidomide or pomalidomide with antibodies to tumor-specific surface antigens in cancer patients.

No significant financial relationships to disclose.

Examining Peplau's pattern integrations in long-term care

Contrary to the societal view that only the frail elderly reside in long-term care facilities, many young adults who require residential care to maintain optimal health, or who are in a rehabilitation program, also live in these facilities. The relationships between residents and caregivers in long-term care facilities may develop into relationships that are more typically familial than professional. With these emerging family-like relationships, the interpersonal pattern interactions may be healthy or unhealthy and may create opportunities for growth or pathology-producing patterns. This article illustrates how applying Peplau's concept of need-pattern integrations in the long-term care setting has the potential to enhance understanding, and subsequently guide interactions, between younger residents and caregivers. The potential is greatest when interactions are guided.

Infusional ECarboF in patients with advanced breast cancer: a very active and well-tolerated out-patient regimen

We performed a trial using the combination of epirubicin 50 mg/m2/day 1, carboplatinum AUC 5/day 1 and continuous 5-fluorouracil (5-FU) 200 mg/m2/day (every 4 weeks for 6 months) to confirm the efficacy and low toxicity profile of this regimen in breast cancer. In 51 patients with metastatic (n = 33) or locally advanced (n = 18) breast cancer the overall response rate was 86% (95% confidence interval (95% CI): 73%-94%): 94% in locally advanced and 81% metastatic disease. Grade 3-4 toxicity was low: 4% of patients presented with febrile neutropenia, 16% with severe palmar-plantar syndrome, 10% with Port-a-cath thrombosis. This study confirms the high efficacy of infusional 5-FU-based regimens and justifies further research into novel promising oral 5-FU derivatives.

Metastatic and nonmetastatic models of retinoblastoma

To generate animal models of retinoblastoma that closely resemble metastatic and nonmetastatic human disease for the purposes of examining tumor biology and developing alternate treatments, human retinoblastoma cell lines were injected into the vitreal cavities of immunodeficient mice. Two reproducible animal models with contrasting biological behaviors analogous to human retinoblastoma have been developed. The Y79 retinoblastoma model demonstrated specific tumor evolution similar to that seen in human invasive and metastatic disease. Y79 retinoblastoma cells formed intraocular tumors that were initially confined to the vitreal cavity. Tumors progressively invaded the retina, subretinal space, choroid, optic nerve head, and anterior chamber of the eye. Tumors progressed into the subarachnoid space and focally invaded the brain. Metastases were detected in the contralateral optic nerve. Large tumors developed extraocular extensions. The histology of the tumors showed a poorly differentiated pattern with high mitotic rate, foci of necrosis, and calcification. The WERI-Rb model more closely resembled nonmetastatic human retinoblastoma. WERI- Rb tumors were localized in the eye with only anterior choroidal invasion at late stages. To examine potential biological differences in vitro, the retinoblastoma cell lines were cocultured with adherent choroid cells or adherent glioma cells which represent the targets of invasive retinoblastoma in vivo. Consistent with the in vivo observations, Y79 cells but not WERI-Rb cells adhere specifically to both the choroidal and the glioma cell lines.

Working With Dave: Application of Peplau's Interpersonal Nursing Theory in the Correctional Environment

Achieving therapeutic relationships with forensic patients is dependent upon nurses' awareness of personal needs, reactions to the patient, recognition of their participation in the pattern, the effects of this participation on others, and the changes they needed to make. Nurses have more extensive contact with the forensic patients than other health care professionals. Consequently, the potential exists for nurses--through interpersonal relationship--to have the greatest therapeutic impact or to engage in patterns that replicate pathology-producing situations (Peplau, 1978). The goal is not that nurses be perfect, but that they be aware of imperfections and capable of exploring them.

When a client develops an attraction: successful resolution versus boundary violation

Psychiatric mental health nursing in correctional institutes is an exciting field, presenting the correctional nurse with a number of challenges. A challenge of particular significance is that encountered when a client develops an attraction to a nurse. Nursing education traditionally has not equipped nurses with the theoretical knowledge or experience to address this phenomenon in clinical practice. Consequently, attractions may not be successfully resolved, resulting in boundary violations that leave the correctional nurse feeling battered. Although attraction in the therapeutic relationship is a well-documented phenomenon in the psychosocial literature, nursing has not addressed this issue sufficiently. Only when the precipitating factors are defined clearly from a sociocultural context, which includes the profession and the correctional environment, can interventions for implementation be identified. The socialization of nurses, how nursing conceptualizes professionalism, gender issues, the atmosphere of the correctional environment and the potential for dual relationships that stem from the multiple roles of the nurse, are factors that the author contends contribute to a lack of boundary setting and maintenance in the nurse-client therapeutic relationship. Consequently, this results in difficulties in assisting a client to resolve attraction successfully.

Adenoid cystic carcinoma of the breast: utility of immunocytochemical study with collagen IV on fine-needle aspiration

A case of adenoid cystic carcinoma (ACC) of the breast in a 71-year-old woman is reported. This neoplasm accounts for about 0.1% of all breast cancers. The mammography showed a well-delineated mass without calcifications. Cytologic examination of percutaneous fine-needle aspiration (FNA) material gave the diagnostic of ACC, which was confirmed by histologic examination. This report emphasizes the utility of immunocytochemical study with collagen IV antibody on FNA material of this uncommon tumor.

The intracellular assembly of antigenic-peptide-class II complexes

The immune system employs remarkable strategies to ensure that foreign antigens, from the most complex pathogens to the simplest proteins, are displayed on the surfaces of cells which are targets of T lymphocyte recognition. At the heart of these strategies is the molecular transformation of a soluble protein antigen to a complex of a small peptide containing the antigenic determinant bound to a cell surface Major Histocompatibility Complex class I or class II protein. This process is termed antigen presentation. Progress in a variety of laboratories over the last several years has yielded a wealth of information about the molecular mechanisms underlying antigen presentation, providing potential new approaches to vaccine design. Here we describe recent studies in our laboratory aimed at elucidating the intracellular site in B lymphocytes in which antigenic peptide-class II complexes are assembled for recognition by helper T cells and the regulation of this assembly process. Our results suggest that processed antigen-class II complexes are assembled in a unique compartment in the endocytic route which contains all the necessary cellular and molecular machinery for assembly and that B cells regulate the assembly process in response to external and internal signals.

Ultrasonographical investigation of periportal fibrosis in children with Schistosoma mansoni infection: reversibility of morbidity seven months after treatment with praziquantel

Five hundred thirty six Sudanese schoolchildren with Schistosoma mansoni infection were treated at random with either 20 mg or 40 mg/kg praziquantel. Seven months later 420 children could be reinvestigated by ultrasonography. Reduction of egg excretion and reversibility of sonographically-proven periportal fibrosis (PF) was not significantly different in the two groups. Schistosoma mansoni-induced PF grade II decreased from 22.9% to 6.7% and grade III from 5.2% to 1.6%. An increased prevalence of PF grade I, from 10% to 29.8% of the investigated patients, was observed. This increase was caused partly by a downshifting of patients who had PF II (n = 45) and PF III (n = 8) before therapy, but also by patients who developed PF I in the seven months after therapy (n = 56). The overall percentage of patients with PF before and after treatment was 38.1%. Of 420 children, 17.4% increased in their PF grade, 55% remained at the same level and 27.6% improved. Children younger than 11 years of age had a higher rate of complete reversibility than older ones. The percentage of patients with hepatomegaly decreased significantly (11.6% to 6.9%; p = 0.001). The rate of splenomegaly remained unchanged. It was concluded that within seven months therapy with praziquantel resulted in a considerable qualitative improvement of PF in Sudanese schoolchildren with S. mansoni infection.

New Brine Saturation Method for Extraction of Light Filth from Corn Meal: Collaborative Study

An improved method has been developed for extracting light filth from corn meal. The proposed method uses only tap water, salt, olive oil, and alcohol, eliminating the need for costly and toxic solvents for the separation. Reports from 8 collaborators showed that recovery was 95.8% for insect fragments and 84.3% for rodent hairs by the proposed method, as compared with 90.6 and 88.6%, respectively, by the official method. The proposed method has been adopted as official first action to replace official method 44.042 for corn meal only.

Metabolism of acyclic and cyclic N-nitrosamines in cultured human bronchi

The metabolism of carcinogenic N-nitrosamines was studied in normal-appearing bronchial specimens obtained from 4 patients. Explants of bronchi were cultured in a chemically defined medium for 7 days. N-Nitrosamines [N-nitrosodimethylamine (DMN), N-nitrosodiethylamine (DEN), N,N'-dinitrosopiperazine (DNP), N-nitrosopyrrolidine (NPy), and N-nitrosopiperidine (NPd)] labeled with 14C were each then added at 100 mumoles for 24 hours. Measurable CO2 was formed by bronchial explants from: 1) DMN, DEN, and NPy in all 4 patients; 2) DNP in 3 of 4 patients; and 3) NPd in only 1 of 4 patients. In all bronchial specimens, these N-nitrosamines and/or their metabolites bound to bronchial mucosal DNA and protein. Binding levels were higher to protein than to DNA. Binding levels of DNP were as high as those with the two acyclic N-nitrosamines DMN and DEN, but binding levels of NPy and NPd were lower. Human bronchus was shown to metabolize and bind acyclic and cyclic N-nitrosamines found in the environment and in tobacco smoke.

Metabolism of dimethylnitrosamine and 1,2-dimethylhydrazine in cultured human bronchi

The metabolic activation of several chemical classes of procarcinogens is being studied in cultured human bronchi. Previous studies have shown that carcinogenic polynuclear aromatic hydrocarbons are metabolically activated by the bronchial epithelium. In the study reported here, dimethylnitrosamine and 1,2-dimethylhydrazine were also found to bind to both cellular DNA and protein. Bronchial DNA was methylated in both the O-6 and N-7 positions of guanine. In addition to polynuclear aromatic hydrocarbons, an aliphatic nitrosamine and a methylhydrazine can now be added to the list of xenobiotic chemical carcinogens metabolized by human bronchus.

Selective intracavitary and coronary hypothermic cardioplegia for myocardial preservation.Clinical, physiologic, and ultrastructural evaluation

Intraoperative myocardial protection was evaluated in two groups of patients undergoing coronary surgery in whom different techniques for cardiac arrest were utilized. In group A, profound selective myocardial hypothermic (15 to 18 C) arrest was achieved by perfusing a coolant (7 to 10 C) into the left ventricular cavity and the coronary circulation. The average anoxic arrest time was 82.5 +/- 27 minutes. In group B, ventricular fibrillation and moderate hypothermia were used. Group A patients showed rapid physiologic recovery, low average myocardial creatinine phosphokinase (MB-CK) isoenzyme levels (7.8 IU) , and a well-preserved myocardial ultrastructure. In group B, three patients showed abnormal physiologic recovery; six patients needed postoperative inotropic support; and in seven patients, electron-microscopy revealed irreversible focal changes. The average MB-CK isoenzyme level was 85.6 IU. Analysis of our data demonstrates that when myocardial protection during coronary bypass grafting is achieved by selective profound intracavitary and coronary cooling, there is physiological, ultrastructural, and biochemical evidence of less intraoperative myocardial damage than when ventricular fibrillation is applied.