Background:

Previous findings have indicated antineoplastic properties of tinzaparin (Innohep®), a commonly used anti-coagulant. Earlier studies have mainly investigated the antineoplastic effects of tinzaparin in animal models and in human cell-lines. In this pilot study the aim is to examine the potential antitumoral effects of tinzaparin in vivo in women with epithelial ovarian cancer (EOC).

Study objectives:

Primary objective: The primary objective of the study is to evaluate the effects of tinzaparin on changes in levels of CA-125 in EOC patients who receive neoadjuvant chemotherapy (NACT).

Secondary objectives: The secondary objective of the study is to explore the impact of tinzaparin on the dynamic of a spectrum of immunological and coagulation factors in EOC patients who receive NACT. Besides, the compliance of tinzaparin injections and adverse events caused by tinzaparin will be described.

This is an open randomized controlled clinical pilot trial (Phase II). The study includes women with the International Federation of Obstetrics and Gynecology (FIGO) stage III-IV EOC selected for neoadjuvant chemotherapy (NACT) and without signs of thromboembolic disease or ongoing treatment of thromboembolic disease. The women will be allocated 1:1 to treatment with tinzaparin 4500 IU/8000 IU (dose depending on woman's weight) subcutaneously once daily or no tinzaparin. The treatment group starts tinzaparin when the primary treatment (chemotherapy) starts. The control group will not receive tinzaparin or other low molecular weight heparin preparations. The NACT consists of carboplatin and paclitaxel, given according to the standard regimen with cycle repeats every 21 days. Pre-treatment, before every cycle of chemotherapy, before delayed primary debulking surgery (DPDS) and three weeks after the last cycle of chemotherapy venous blood samples will be taken for measuring the biomarkers hemoglobin, platelets, leucocytes, C-reactive protein (CRP), albumin, cancer antigen-125 (CA-125), Tissue Factor, D-dimer, soluble P-selectin, thrombin-antithrombin complex and thrombin generation potential. Furthermore, a panel of 92 inflammation-associated proteins will be analyzed by a by a high-sensitivity Proximity Extension Assay at baseline, visit 5 and visit 8 or 9. After three cycles of NACT, the patient will be evaluated clinically and with imaging diagnostics in order to determine whether the patient should undergo DPDS. In the investigators´ setting, > 80% of patients receiving NACT for EOC undergo DPDS. After DPDS, all patients will be treated with tinzaparin for 28 days according to clinical practice concerning postoperative thromboembolic prophylaxis and thereafter continue the chemotherapy for additional two-three courses. The participants who were allocated to tinzaparin during the NACT can chose to continue the tinzaparin after ending the postoperative thromboembolic prophylactic tinzaparin treatment for additional 2-3 courses. The biomarkers will be measured preoperatively and four weeks postoperatively after DPDS and then before each course of chemotherapy given during the primary treatment. The women who do not undergo surgery will remain included in the study for the following three cycles of chemotherapy. Thus, the total study period constitutes 22-29 weeks.

Inclusion Criteria:

• The subject has given written consent to participate in the study.
• Age 18 and above
• Epithelial ovarian, fallopian tube or peritoneal cancer, or abdominal cancer where a biopsy indicates an origin from the ovary, fallopian tube or peritoneum.
• Histology diagnosis of either high grade serous carcinoma, endometroid carcinoma or clear cell carcinoma.
• FIGO stage III-IV disease.
• Planned for platinum-based chemotherapy
• Prior to start of NACT pregnancy should be ruled out by menstrual history or in unclear cases by a urine hCG test.
• Women of childbearing potential should use a safe birth control method (combined hormonal contraception, progesterone only hormonal contraception, intra uterine device, bilateral tubal occlusion, vasectomized partner, sexual abstinence, male or female condom, diaphragm with spermicide).
• WHO Performance Status 0-2
• Weight 50-150 kg
• CA-125-level ≥250 kIE/L at diagnosis

Exclusion Criteria:

• Concomitant treatment with heparins, low molecular weight heparins, warfarin or non-vitamin K antagonist oral anticoagulants. Platelet inhibitors are allowed.

• Treatment with heparins, low molecular weight heparins or non-vitamin K antagonist oral anticoagulants within the last year.

• Known or suspected allergies against any product included in the study

• Ongoing pregnancy, independent of gestational age. Breastfeeding or planned pregnancy

• EOC disclosed at Cesarean section

• Abdominal surgery or other major surgery within the last year

• Mental inability, reluctance or language difficulties that result in difficulty understanding the meaning of study participation

• Treatment or disease which, according to the investigator, can affect treatment or study results

• Known brain metastasis

• Participation or recent participation (within the last 30 days) in a clinical study with an investigational product

• Ongoing treatment of thromboembolic disease.

• Thromboembolic disease within the last year.

• Hypersensitivity to the active substance (tinzaparin) or any of the excipients.

• Serious hemorrhage or conditions predisposing to serious hemorrhage. Serious hemorrhage is defined as fulfilling any one of these three criteria:

  1. occurs in a critical area or organ (e.g. intracranial, intraspinal, intraocular, retroperitoneal, intra-articular or pericardial, intra-uterine or intramuscular with compartment syndrome),
  2. causes a fall in hemoglobin level of 20 g/L (1.24 mmol/L) or more, or
  3. leads to transfusion of two or more units of whole blood or red blood cells.

• Severe coagulation disorder.

• Acute gastro duodenal ulcer.

• Septic endocarditis.

• Previous heparin-induced thrombocytopenia.

• WHO Performance Status >2.

• E-GFR <30ml/min (analyzed no more than 14 days before start of treatment with investigational product)

• Platelets <100 x10^9/L (analyzed no more than 14 days before start of treatment with investigational product)

• Treatment for other known malignancy within the last year (except basal cell carcinoma)