Patterns of VTE Treatment with Noac in Cancer Patients - Results of the Prospective Dresden Noac Registry (NCT01588119)
Authors: Marten Sandra , Tittl Luise , Naue Christiane , Beyer-Westendorf Jan 
Published: November 2019

Background: Until recently, patients with cancer associated thrombosis (CAT) were predominantly treated with low-molecular weight heparin (LMWH) but trial data and updated guidelines suggest that direct oral anticoagulants (DOAC) may represent feasible and convenient oral alternatives. However, most data supporting this relate to 6-12 months outcomes only and long-term data in this setting are scarce
Aims: To evaluate the effectiveness and safety of CAT treatment with DOAC in daily care.
Patients and methods: From the multicentric Dresden NOAC Registry, long-term outcomes of a subgroup of CAT patients (active or recent cancer, defined as cancer therapy within 5 years prior to thrombosis) receiving CAT therapy with DOAC were evaluated, based on prospectively collected data and centrally adjudicated outcome events.
Results: Of the 1667 VTE patients enrolled in the registry until 30th June 2019, 186 patients (11.2%) were identified to have CAT (mean age 67.3 years; 61.3% male). At enrolment, cancer was reported as active in 97 (52.2) cases and recent in 89 (47.8) cases. Solid malignancies were diagnosed in 163 (87.6%) cases were, the remaining 23 (12.4%) cases were hematologic malignancies; table 1; figure 1). Of the 97 cases with active malignancies, 43.3% had metastatic disease. CAT treatment consisted of rivaroxaban in 80 (43.0%) patients, 66 (35.5%) received edoxaban and 40 (21.5%) apixaban.
During follow-up (mean 27.8 months, range 0.5 - 88.6), 14 patients experienced recurrent VTE events (7.5 %; incidence rate 3.5/100 pt. years) of which 4 occurred during DOAC treatment and 10 after discontinuation or during prolonged (&gt;3d) DOAC interruption (figure 2a). During DOAC exposure (within 3 days of last intake), major bleeding occurred in 15 patients (8.1%; incidence rate 5.9/100 pt. years; figure 2b) and presented as gastrointestinal (GI) bleeding in 7, intracranial bleeding in 3 and in other bleeding manifestations in 5 cases. For 34 patients with GI cancer, the incidence rate for major bleeding was 13.3/100 pt. years and all four major bleedings in this group presented as upper GI bleed.
40 patients died during FU (21.5%; incidence rate 9.4/100 pt. years). Causes of death included terminal malignant disease (n=22), infection (n=6), fatal bleeding (n=4), age related death (n=3), fatal cardiovascular event (n=3), and other reasons (n=2).
Conclusions: Our results now contribute long-term data of DOAC treatment for CAT. Incidence rates of recurrent VTE and major bleeding were consistent with the results from recent randomized trials in CAT. Most VTE recurrences occurred after interruption or discontinuation of DOAC, which indicates the importance of continued therapy especially for patients with active cancer. On-treatment rates of major bleeding were comparable for patients with recent or active cancer, indicating a need for an individualized risk-benefit assessment, especially since patients with recent cancer were at lower risk for VTE recurrence. Our findings of higher major bleeding rates in patients with GI cancer (both active and recent) is in line with the observations in randomized trials and supports guidelines recommendations, cautioning against DOAC use in CAT patients at high risk for bleeding, such as GI cancer patients.

Disclosures
Marten: Daiichi Sankyo: Honoraria; Bayer HealthCare: Honoraria. Tittl:Daiichi Sankyo: Honoraria. Beyer-Westendorf:Pfizer: Honoraria, Research Funding; Bayer HealthCare: Honoraria, Research Funding; Daiichi Sankyo: Honoraria, Research Funding; Boehringer Ingelheim: Honoraria, Research Funding.