CLL Stromal cell protect - PowerPoint Presentation

CLL Stromal cell protect Conventional therapies Versteckspiel im Wald by Friedrich Eduard Meyerheim (1808-1879) The “outside ” (microenvironment) of the CLL cell: new insights into disease biology and new therapeutic targets Jan Burger, MD PhD Department of Leukemia MD Anderson Cancer Center

Microenvironment in CLL Larger proliferating CLL cells form proliferation centers (pseudofollicles), a hallmark finding in CLL Within pseudofollicles, CLL cells are in close contact with accessory cell (stomal cells, T cells) From: Soma LA et al, Human Pathology. 2006;37:152-159 From: PE Patten et al. Blood. 2008;111:5173-81 Messmer BT, et al. J Clin Invest. 115(3): 755-764, 03/2005

Microenvironment in CLL: a-SMA and CD14/68+ cells From: J Rual et al. Clinical Cancer Research 12, 5622-31, 2006 Bhattacharya and Mertens et al., Leukemia (2011) 25, 722–726 CLL#1 CLL#2 CLL#3 normal tonsil

CLL in vitro model: BMSC co-cultures Standardized CLL- stroma co-culture conditions for drug testingIdeal for testing drug combinations

From: Sivina et al., Leukemia 26:1812-20, 08/2012

In vitro model : Nurselike cells CXCR4 † CXCL12 CXCL13 CXCR5 ¶ CD31, plexin-B1 CD38, CD100 ‡ BAFF, APRIL BAFF-R, BCMA, TACI* * Nishio M et al. Blood 106:1012-20, 2005 ¶ Burkle A et al. Blood 110:3316-25, 2007 † Burger JA et al. Blood 96, 2655-63, 2000 ‡ Deaglio S et al. Blood 105(8):3042-50, 2005 # Burger JA et al. Blood. 113:3050-8, 2009 ?antigen BCR #

The lymph node microenvironment promotes BCR signalingCLL cells isolated from lymph nodes showed upregulation of CCL3 and CCL4 LN signature GEPs have a remarkable similarity to GEP of CLL cells after co-cultured with nurselike cells, including upregulation of CCL3, CCL4, EGR2, EGR3, and MYC From: Y Herishanu et al., Blood. 2011 Jan 13;117(2):563-74 CCL3 CCL4

Summary: molecular interactions in the CLL microenvironmentThe moleculoar interactions between CLL cells and their microenvironment are complexSoluble factors, BCR signaling and cell-cell interactions are important Chemokine receptors and BCR-associated kinases are current drug targets From: Burger JA et al., Blood. 2009 Oct 15;114(16):3367-75

Targeting the microenvironment in CLL: Plerixafor (AMD3100)Plerixafor is a CXCR4 antagonist and blocks HIV-1 entry into T cells Plerixafor is a bicyclam Plerixafor binds to Asp171 in TM-IV and Asp262 in TM-VI of CXCR4 From: Gerlach LE et al., J. Biol. Chem. 276:14153, 2001

Results: Best Confirmed Response* 0.08 mg/kg n=3 0.16 mg/kg n=40.24 mg/kg n=30.32 mg/kg n=70.42 mg/kgn=4 Overall n=21 No. of Evaluable Patients 3 3 2 7 3 18 Evaluable patients with, n (%): Complete Response Partial Response (PR) Stable Disease (SD) Progressive Disease Relapsed Disease Treatment Failure 0 2 (67) 0 1 (33) 0 0 0 0 0 3 (100) 0 0 0 0 0 2 (100) 0 0 0 4 (57) 2 (29) 1 (14) 0 0 0 2 (67) 0 0 0 1 (33) 0 8 (44) 2 (11) 7 (39) 0 1 (6) * Responses were assessed based on definitions provided by the National Cancer Institute-sponsored Working Group guidelines for chronic lymphocytic leukemia. Cheson BD, et al; Blood. 1996 Jun 15;87(12):4990-7.

Targeting of BCR signaling in CLLBCR-associated kinases are targets of new drugs in preclinical and clinical development SYK (Spleen tyrosine kinase) inhibitors: fostamatinib (R788)BTK ( Bruton’s tyrosine kinase) inhibitors: ibrutinib (formerly: PCI-32765) PI3 kinases: Isoform-Selective Inhibitor of PI 3-Kinases, GS-110 ( formerly: CAL-101) From: Nat Rev Immunol 2:945

Pattern of Response: Blood Lymphocytes vs Lymph Nodes 12 Mean % Change from Baseline Cycle ALC SPD SCR(61) 1(60) 2(57) 3(52) 4(50) 5(51) 6(47) 7(46) 8(48) 9(43) 10(38) 11(31) SPD- sum of products of lymph node dimension

Inhibition of chemotaxis CXCL12 CXCL13 Ctrl PCI-32765 ( 10 nM) PCI-32765 (100 nM) PCI-32765 ( 1000 nM) Migrated cells (% of input ) means of 6 patients ± SEM, *p≤0.05 compared to Medium Medium AMD3100 * * + chemokine Medium Ctrl + chemokine * * PCI-32765 ( 10 nM) PCI-32765 ( 100 nM) PCI-32765 ( 1000 nM) S. Ponader et al., Blood 119: 1182-9, 2012

GS-1101 (CAL-101) inhibits CLL cell chemotaxis towards CXCL12 and CXCL13 Hoellenriegel J et al.; Blood 118(13):3603-12, 09/2011

GS-1101 (CAL-101) antagonizes CLL cell migration beneath marrow stroma cells (pseudoemperipolesis) Hoellenriegel J et al.; Blood 118(13):3603-12, 09/2011

PCI-32765: effects on adhesion and migration From: Rooij et al., Blood 119: 2590-2594, 2012 VCAM-1adhesion assayChemotaxisassay

Tcl1 MOUSE model of cll Effects of Btk inhibitor ibrutinib Vehicle control Ibrutinib 25mg/kg/day 0 10 20 Ctrl (n=4) 2.5 (n=3) 25 (n=4) 25 (n=4) Outliers Body weight (g) Ibrutinib (mg/kg/day) P=0.356 P=0.137 30 P=0.028 2.5 mg/kg/d 25mg/kg/day Control + Ibrutinib 0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 Spleen weight (g) P=0.64 P=0.05 P=0.01 Ctrl (n=4) 2.5 (n=3) 25 (n=4) 25 (n=4) Outliers Ibrutinib (mg/kg/day) S. Ponader et al., Blood 119: 1182-9, 2012

BCR-related Biomarker: CCL3, CCL4 (MIP-1 α,β) CCL3CCL4 pg/mL time (days) pre-treatment S. Ponader et al., Blood 119: 1182-9, 2012 pre-treatment Ibrutinib trial GS-1101 trial Hoellenriegel J et al.; Blood 118(13):3603-12, 09/2011

Key effects of inhibitors of BCR-associated kinases Btk, Syk, PI3Kδ Inhibitors of BCR signaling and block survival and proliferation, but also homing and tissue retention of CLL cells Effects on either pathway differ between patients Adapted after: Burger JA et al., Blood. 2009 Oct 15;114(16):3367-75

Summary and outlookChemokine receptors and adhesion molecules are essential for tissue homing and migration of CLL cellsCXCR4 and BCR-associated kinases (SYK, BTK, PI3K δ) are targeted in clinical trials in CLLThese therapies “mobilize” CLL cells from the tissues into the bloodThere is promising clinical activity of these new therapeutic approaches