Trial Information

Pharmacokinetics of Low Molecular Weight Heparin in Cancer Patients Compared to Patients With Unstable Angina Pectoris; The Possible Role of Heparanase

Scientific background. The increased risk for venous thromboembolism (VTE) in cancer has
long been recognized (1). Since first described by Trousseau in 1865, many aspects of this
complex relationship are still obscure (2). Cancer patients have an increased risk for
developing thrombosis. Similarly, patients presenting with idiopathic VTE are considered to
have a higher risk of developing cancer (3). Approximately 10% of patients with idiopathic
VTE harbor an underlying malignancy that can be detected by an extensive diagnostic work-up
(4). Clinical data indicate that cancer alone is associated with a 4.1- fold risk of
thrombosis, and chemotherapy increases the risk to 6.1- folds (5). Cancer patients develop
postoperative VTE at least 2- folds more than patients without cancer undergoing the same
surgical procedure (6). Treatment of VTE involves the administration of heparin, low
molecular weight heparin (LMWH) or coumarin derivatives. Beside its anticoagulant effects,
LMWH may also have an anti-tumoral effect (7-12). The use of LMWH relative to coumarin
derivatives was associated with improved survival in patients with solid tumors who did not
have metastatic disease at the time of an acute VTE (9). Moreover, addition of LMWH to
chemotherapy increased survival of patients with small cell lung cancer (10).

Heparan sulfate proteoglycans (HSPGs) are ubiquitous macromolecules associated with the cell
surface and extracellular matrix (ECM) of a wide range of cells of vertebrate and
invertebrate tissues. Heparin is structurally related to heparan sulfate (HS), but has
higher N- and O-sulfate contents (13). Mammalian endoglycosidase, capable of partially
depolymerizing HS chains and commonly referred to as heparanase, has been identified in a
variety of cell types and tissues, primarily cancer cells, activated cells of the immune
system, platelets, and placenta (14-17). Heparanase is synthesized as a latent 65 kDa
precursor whose activation involves proteolytic cleavage at two potential sites located at
the N-terminal region of the molecule (Glu109 -Ser110 and Gln157 -lys158), resulting in the
formation of two protein subunits that heterodimerize and form the active heparanase enzyme
(18). Expression of heparanase correlates with the metastatic potential of human tumor cells
(14-16, 19). Furthermore, elevated levels of heparanase were detected in the urine of some
patients with aggressive metastatic disease (20). Heparin, LMWH, non-anticoagulant and
chemically modified species of heparin (21, 22), as well as other polysaccharides (23, 24)
which inhibit experimental metastasis, also inhibit tumor cell heparanase, while other
related compounds had a small or no effect on both parameters (21-24). Recently, we
demonstrated that the anticoagulant activities of heparin and LMWH can be neutralized by
their pre-incubation with heparanase. Transgenic mice overexpressing heparanase, exhibited a
hyper-coagulable phenotype expressed by a markedly shorter base-line APTT compared to
control mice (25). These results may suggest that resistance to heparin, described in
patients with malignancies (26, 27), could be attributed, in part, to high levels of
heparanase often observed in cells (28, 29) and body fluids (20) of patients with an
aggressive malignant disease. Degradation of heparin and LMWH by heparanase in vivo may be
relevant in situations in which heparanase is over-expressed, and treatment with heparin or
LMWH is needed (e.g., deep venous thrombosis in patients with pancreatic carcinoma) (29,
30). The pharmacokinetics of LMWH (i.e. the time course of absorption, distribution,
metabolism, and degradation) as reflected by its effects upon factor Xa activity, was
elucidated in several subgroups of patients (e.g. patients with renal failure, pregnant
women…), but to the best of our knowledge was not addressed in patients with advanced solid
tumors.

Objectives & expected significance. In view of the above described biological significance
of the heparanase enzyme, and taking into account our recent in vitro and in vivo results
(heparanase capability to cleave heparin and LMWH; and the altered coagulation profile in
transgenic mice overexpressing heparanase) (25), we propose to focus on the following
specific aims:

I) Measure plasma and urine heparanase levels in patients with advanced cancer suffering
from VTE, and compare it to controls without cancer.

II) Elucidate the pharmacokinetics of LMWH in patients with advanced solid tumors (AST)
suffering from VTE, and compare it to the pharmacokinetics of LMWH in patients with unstable
angina pectoris.

III) Determine the correlation between heparanase blood levels and the pharmacokinetics of
LMWH, if any.

References

1. Rickles FR. Mechanisms of cancer-induced thrombosis in cancer. Pathophysiol Haemost
Thromb. 2006; 35: 103-110.

2. Trousseau A: Phlegmasia alba dolens, in: Clinique Medicale de l'Hotel Dieu de Paris.
Vol 3, ed 2. Balliere, Paris, 1865; pp 654-712.

3. Valente M, Ponte E. Thrombosis and cancer. Minerva Cardioangiol. 2000; 48: 117-127.

4. Prandoni P. Cancer and venous thromboembolism. Clinical implications of strong
association. Pathophysiol Haemost Thromb. 2006; 35: 111-115.

5. Heit JA, Silverstein MD, Mohr DN, Petterson TM, O'Fallon WM, Melton LJ 3rd. Risk
factors for deep vein thrombosis and pulmonary embolism: a population-based
case-control study. Arch Intern Med. 2000; 160: 809-815.

6. Rickles FR, Levine MN. Epidemiology of thrombosis in cancer. Acta Haematol. 2001; 106:
6-12.

7. von Tempelhoff GF, Harenberg J, Niemann F, Hommel G, Kirkpatrick CJ, Heilmann L. Effect
of low molecular weight heparin (Certoparin) versus unfractionated heparin on cancer
survival following breast and pelvic cancer surgery: A prospective randomized
double-blind trial. Int J Oncol. 2000; 16: 815-824.

8. Kakkar AK, Levine MN, Kadziola Z, Lemoine NR, Low V, Patel HK, Rustin G, Thomas M,
Quigley M, Williamson RC. Low molecular weight heparin, therapy with dalteparin, and
survival in advanced cancer: the fragmin advanced malignancy outcome study (FAMOUS). J
Clin Oncol. 2004; 10: 1944-1948.

9. Lee AY, Rickles FR, Julian JA, Gent M, Baker RI, Bowden C, Kakkar AK, Prins M, Levine
MN. Randomized comparison of low molecular weight heparin and coumarin derivatives on
the survival of patients with cancer and venous thromboembolism. J Clin Oncol. 2005;
23: 2123-2129.

10. Altinbas M, Coskun HS, Er O, Ozkan M, Eser B, Unal A, Cetin M, Soyuer S. A randomized
clinical trial of combination chemotherapy with and without low-molecular-weight
heparin in small cell lung cancer. J Thromb Haemost. 2004; 2: 1266-1271.

11. Klerk CP, Smorenburg SM, Otten HM, Lensing AW, Prins MH, Piovella F, Prandoni P, Bos
MM, Richel DJ, van Tienhoven G, Buller HR. The effect of low molecular weight heparin
on survival in patients with advanced malignancy. J Clin Oncol. 2005; 23: 2130-2135.

12. Meyer G, Marjanovic Z, Valcke J, Lorcerie B, Gruel Y, Solal-Celigny P, Le Maignan C,
Extra JM, Cottu P, Farge D. Comparison of low-molecular-weight heparin and warfarin for
the secondary prevention of venous thromboembolism in patients with cancer: a
randomized controlled study. Arch Intern Med. 2002; 162:1729-1735.

13. Casu B, Lindahl U. Structure and biological interactions of heparin and heparan
sulfate. Adv Carbohydr Chem Biochem. 2001; 57: 159-206.

14. Parish CR, Freeman C, Hulett MD. Heparanase: a key enzyme involved in cell invasion.
Biochim Biophys Acta. 2001; 1471: M99-108.

15. Vlodavsky I, Friedmann Y. Molecular properties and involvement of heparanase in cancer
metastasis and angiogenesis. J Clin Invest. 2001; 108: 341-347.

16. Nakajima M, Irimura T, Nicolson GL. Heparanases and tumor metastasis. J Cell Biochem.
1988; 36:157-167.

17. Dempsey LA, Brunn GJ, Platt JL. Heparanase, a potential regulator of cell-matrix
interactions. Trends Biochem Sci. 2000; 25: 349-351.

18. Levy-Adam F, Miao HQ, Heinrikson RL, Vlodavsky I, Ilan N. Heterodimer formation is
essential for heparanase enzymatic activity. Biochem Biophy Res Commun. 2003; 308:
885-891.

19. Vlodavsky I, Friedmann Y, Elkin M, Aingorn H, Atzmon R, Ishai-Michaeli R, Bitan M,
Pappo O, Peretz T, Michal I, Spector L, Pecker I. Mammalian heparanase: gene cloning,
expression and function in tumor progression and metastasis. Nat Med. 1999; 5: 793-802.

20. Shafat I, Zchria E, Nisman B, Nadir Y, Nakhoul F, Vlodavsky I, Ilan N. An ELISA method
for the detection and quantification of human heparanase. Biochem Biophy Res Commun.
2006; 341: 958-963.

21. Vlodavsky I, Mohsen M, Lider O, Svahn CM, Ekre HP, Vigoda M, Ishai-Michaeli R, Peretz
T. Inhibition of tumor metastasis by heparanase inhibiting species of heparin. Invasion
Metastasis. 1994; 14: 290-302.

22. Parish CR, Coombe DR, Jakobsen KB, Bennett FA, Underwood PA. Evidence that sulphated
polysaccharides inhibit tumour metastasis by blocking tumour-cell-derived heparanases.
Int J Cancer. 1987; 40: 511-518.

23. Parish CR, Freeman C, Brown KJ, Francis DJ, Cowden WB. Identification of sulfated
oligosaccharide-based inhibitors of tumor growth and metastasis using novel in vitro
assays for angiogenesis and heparanase activity. Cancer Res. 1999; 59: 3433-3441.

24. Miao HQ, Elkin M, Aingorn E, Ishai-Michaeli R, Stein CA, Vlodavsky I. Inhibition of
heparanase activity and tumor metastasis by laminarin sulfate and synthetic
phosphorothioate oligodeoxynucleotides. Int J Cancer. 1999; 83: 424-431.

25. Nasser NJ, Sarig G, Brenner B, Nevo E, Goldshmidt O, Zcharia E, Li JP, Vlodavsky I.
Heparanase neutralizes the anticoagulation properties of heparin and
low-molecular-weight heparin. J Thromb Haemost. 2006; 4: 560-565.

26. Levy JH. Heparin resistance and antithrombin: should it still be called heparin
resistance? Journal of cardiovascular anesthesia. 2004; 18: 129-130.

27. Deitcher SR. Cancer and thrombosis: mechanisms and treatment. J Thromb Thrombolysis.
2003; 16: 21-31.

28. Gohji K, Hirano H, Okamoto M, Kitazawa S, Toyoshima M, Dong J, Katsuoka Y, Nakajima M.
Expression of three extracellular matrix degradative enzymes in bladder cancer. Int J
Cancer. 2001; 95: 295-301.

29. Koliopanos A, Friess H, Kleeff J, Shi X, Liao Q, Pecker I, Vlodavsky I, Zimmermann A,
Buchler MW. Heparanase expression in primary and metastatic pancreatic cancer. Cancer
Res. 2001; 61: 4655-59.

30. Kim AW, Xu X, Hollinger EF, Gattuso P, Godellas CV, Prinz RA. Human heparanase-1 gene
expression in pancreatic adenocarcinoma. J Gastrointest Surg. 2002; 6: 167-172.