A Study to Gather Information About Rivaroxaban in Patients in the United Kingdom Who Have Cancer and Thrombosis (OSCAR-UK)

Observational Studies in Cancer Associated Thrombosis for Rivaroxaban - United Kingdom Cohort (OSCAR-UK)

Patients with cancer are more likely than those without cancer to develop blood clots (deep vein thrombosis and pulmonary embolism), which are treated using blood thinners (anticoagulants). When clots occur, cancer patients carry a higher risk of recurring clots and more likely to bleed on blood thinning treatments. Therefore, it is critical to use blood thinners that optimize the safety and benefits.

There are two main types of blood thinners that are recommended. The tablets which are direct-acting oral anticoagulants and the injections (low molecular-weight heparin). Clinical trials show the tablets may reduce clot risk but may potentially lead to more frequent bleeding, particularly in those with certain risk factors such as stomach ulcers, previous bleeding problems, certain cancer type.

We aim to examine the effectiveness and safety of the tablets versus the injections for treatment of clots in cancer patients, to better understand these treatments' benefits and risks.

Inclusion Criteria:

• Be ≥18 years of age at the time of anticoagulation initiation
• Have active cancer and acute deep vein thrombosis (DVT) and/or pulmonary embolism (PE)
• Treated with rivaroxaban (or any DOAC) or LMWH as their first recorded anticoagulant prescription 7 to 30 days post-acute CAT event diagnosis
• Have been active in the data set for at least 12-months prior to the index event and had at least one provider visit in the 12-months prior to the acute VTE event

Exclusion Criteria:

• Evidence of atrial fibrillation, recent hip/knee replacement (with 90 days of CAT), ongoing VTE treatment, valvular heart disease defined as any rheumatic heart disease, mitral stenosis or mitral valve repair/replacement
• History of inferior vena cava filter before cohort entry
• vitamin K antagonist (VKA) use between cohort entry and index day (initiation of DOAC or LMWH)
• Evidence of any type of therapeutic anticoagulation use during all available look-back period per written prescription or patient self-report
• Initiation of rivaroxaban or other DOACs or LMWH during the study period at non-therapeutic doses (e.g., enoxaparin at a dose other than 1 mg/kg twice daily or 1.5 mg/kg once daily; dalteparin at a dose other than 200 IU/kg of total body weight)
• Pregnancy
• Recording indicative of palliative care before cohort entry
• Any clinically-relevant bleeding-related d hospitalization or VTE recurrence between the initial CAT and the start of observation