Evaluation of Tinzaparin Sodium for Venous Thromboembolism Prophylaxis in Patients with Metastatic Colorectal Cancer Initiating First-Line Systemic Therapy

The primary objective of this study is to evaluate the **efficacy** of a 4-month prophylaxis regimen using low molecular weight heparin (LMWH), specifically **tinzaparin**, in preventing symptomatic or incidental venous thromboembolism (VTE) events in patients with stage IV metastatic colorectal cancer (mCRC) who are initiating first-line systemic treatment, which may include chemotherapy with or without targeted therapy. This objective is clinically relevant as patients with mCRC are at an increased risk of VTE, which can significantly impact morbidity and mortality. Effective prophylaxis could improve patient outcomes by reducing the incidence of these thromboembolic events.

The clinical trial involves participants diagnosed with **Stage IV colon or rectal adenocarcinoma (mCRC)**. The study population includes both male and female subjects aged 18 years and older. Participants are required to have a histologically confirmed diagnosis of stage IV colon or rectal adenocarcinoma and must be beginning their first line of treatment for metastatic disease, which may include chemotherapy with or without targeted therapy or immunotherapy. The trial population was selected based on specific inclusion criteria, including an Eastern Cooperative Oncology Group (ECOG) performance status of 0-2 and a life expectancy greater than six months. The study does not provide information on the total number of participants. The trial includes a vulnerable population, and participants' general health status is assessed to ensure they meet the necessary criteria for inclusion. The sponsor has not provided information regarding lifestyle considerations such as diet, physical activity, or habits.

The clinical trial is designed to evaluate the efficacy of a 4-month prophylaxis regimen using **tinzaparin sodium** for the prevention of venous thromboembolic events (VTE) in patients with stage IV colorectal cancer (mCRC) initiating first-line systemic treatment. This study is a randomized, double-blind, controlled trial, ensuring that neither the participants nor the investigators are aware of the treatment allocations, thus minimizing bias. The trial is expected to run from December 2022 to April 2025, with participant involvement lasting up to four months, corresponding to the maximum treatment period.

Participants will undergo a series of study visits, beginning with an inclusion (screening) visit to confirm eligibility based on criteria such as age, diagnosis, and performance status. Follow-up visits will be scheduled to monitor the occurrence of VTE events and assess the safety and efficacy of the treatment. The primary endpoint is the cumulative incidence of VTE events, including symptomatic and incidental occurrences. The study will conclude with an end-of-study visit to evaluate the overall outcomes and gather final data.

Participants are expected to remain in the study for the full duration unless specific conditions necessitate early termination. These conditions include adverse reactions to the treatment, withdrawal of consent, or any significant protocol deviations. The trial is categorized as low-intervention, aligning with standard clinical practices for managing metastatic colorectal cancer, and the use of tinzaparin is consistent with clinical guidelines for high-risk patients. The trial's design and procedures are structured to ensure rigorous assessment of the prophylactic efficacy of tinzaparin in this patient population.

The clinical trial involves the administration of **tinzaparin sodium**, an antithrombotic agent, for the prophylaxis of venous thromboembolic disease in patients with metastatic colorectal cancer. The experimental medication is provided in two formulations. The first formulation is "innohep 8,000 UI anti-Xa/0.4 ml," which is a **solution for injection** in pre-filled syringes. This formulation is administered via **subcutaneous injection**. The maximum daily dose is 8,000 IU, and the treatment period is up to 4 months. The administration schedule is designed to ensure consistent dosing, and participant compliance is monitored throughout the study.

The second formulation used in the trial is "innohep 4,500 UI anti-Xa/0.45 ml," also a **solution for injection** in pre-filled syringes. This formulation is similarly administered via **subcutaneous injection**. The maximum daily dose for this formulation is 4,500 IU, with a treatment period extending up to 4 months. As with the first formulation, dosing schedules are strictly adhered to, and compliance is monitored to ensure the integrity of the trial results.

Both formulations of tinzaparin sodium are manufactured by LEO Pharma A/S and are not pediatric formulations. The trial does not involve any orphan drug designations. No non-experimental treatments, such as standard-of-care therapy, placebo, or comparator treatments, are specified in the trial protocol. The study's main objective is to evaluate the efficacy of a 4-month prophylaxis regimen with low molecular weight heparin (LMWH) tinzaparin in preventing symptomatic or incidental venous thromboembolism (VTE) events in patients with stage IV colorectal cancer initiating first-line systemic treatment.

The efficacy of the clinical trial will be assessed by evaluating the primary efficacy endpoint, which is the cumulative incidence of any **venous thromboembolism (VTE)** event. This includes symptomatic non-fatal pulmonary thromboembolism (PE), symptomatic lower-limb deep vein thromboembolism (sllDVT), symptomatic upper extremity deep vein thromboembolism (sueDVT), incidentally diagnosed PE or proximal DVT, symptomatic central venous catheter thromboembolism, incidentally visceral vein thrombosis (iVVT), symptomatic visceral vein thrombosis (sVVT), and VTE-related deaths. The trial aims to evaluate the efficacy of a 4-month prophylaxis with low molecular weight heparin (LMWH), specifically tinzaparin, in preventing symptomatic or incidental VTE events in patients with stage IV colorectal cancer (mCRC) who are initiating first-line systemic treatment, which may include chemotherapy with or without targeted therapy.