Long-Term Efficacy and Safety of Low-Molecular-Weight Heparins (LMWH) for Cancer-Associated Venous Thromboembolism (VTE) in Tropique, a Prospective Non-Interventional Observational Study
Authors: Farge Dominique , Debourdeau Philippe , Gorin Norbert Claude , Lamblin Anne , Cajfinger Francis 
Published: October 2019

Introduction

Long-term treatment with LMWH is the standard therapy for patients with cancer-associated VTE. Recommended treatment regimen include the prescription of LMWH at treatment doses according to approved administration schedule for at least 3 months in the absence of severe renal insufficiency (CrCl<30 mL/min) [1, 2]. The TROPIQUE study documented the prescription and use of long-term treatment with LMWH in cancer patients. Here we report the findings on the secondary outcomes, clinical efficacy and safety.

Methods

Adult patients with cancer-associated VTE receiving antineoplastic treatment or palliative care were eligible to participate. Efficacy outcomes measures were VTE recurrence including deep-vein thrombosis (DVT) and pulmonary embolism (PE), visceral thrombosis and central venous catheter (CVC)-associated thrombosis. Safety outcomes included all and major bleeding according to ISTH definition [3], thrombocytopenia and deaths. Incidences of 7% of VTE recurrence and 6% of major bleeding were expected. With a sample of 384 patients, the rate of VTE recurrence and major bleeding would be detected with a precision of ±2.6% and ±2.4%, respectively, with a 95% confidence interval. A total of 400 patients were therefore planned to be included in the study.

Results

A total of 409 patients with symptomatic cancer-associated VTE (Table 1) aged 65±12.1 years of whom 49.9% female were consecutively included from November 2012 to August 2013. A history of previous VTE was found in 54 (13.2%), surgery or trauma in 100 (24.4%), CVC in 303 (74.1%) and an immobilization over 1 month in 47 (11.5%) patients, respectively. At study inclusion, 30 (7.3%) patients had platelet count ≤ 100 x109/L, and 129 (31.5%) had reported anemia while 16 (3.9%) patients had a history of bleeding in the last month. At baseline, more than 80% of patients presented with at least a PE or a lower-limb DVT of s.

Table 1 VTE diagnosis at baseline (patients at least with one of the following) VTE diagnosis (at least one of the following) n (%) PE 145 (35.5) DVT lower limb 193 (47.2) Proximal 107 (56.0) Distal 72 (37.7) DVT upper limb 45 (11.0) Visceral thrombosis 16 (3.9) CVC-associated thrombosis 66 (16.1)

Mean treatment duration was 5.28 ± 2.07 months. As the majority of patients were treated with tinzaparin (73.6%), clinical outcomes are therefore presented for tinzaparin, other LMWH and all LMWH (Table 2).

A total of 21 events of VTE recurrence occurred in 19 patients during the overall study period, with a Kaplan-Meir estimate of the probability of VTE recurrence at 6 months of 6.1%.

Table 2 Outcomes in patients with cancer-associated VTE treated with long-term LMWH [n (%)]. Patients treated Tinzaparin n=301 Other LMWH n=108 All LMWH n=409 Patients documented n=292 n=100 n=392 Patients with at least 14 (4.8) 5 (5) 19 (4.8)  one VTE recurrence - - - Events (2 patients had 3 4 7  more than one event) 5 1 6 DVT 0 1 1 PE 6 1 7 Visceral thrombosis CVC-associated thrombosis Bleeding n=292 n=100 n=392 All 44 (15.1) 11 (11.0) 55 (14.0) Major 16 (5.5) 7 (7.0) 23 (5.9) Thrombocytopenia n=290 n=100 n=390  (n platelets/mm3) 53 (18.3) 15 (15.0) 68 (17.4) All n=65 n=17 n=82 < 50,000 22 5 27 Drop > 50% 15 2 17 Deaths n=301 n=107 n=408 All 102 (33.9) 44 (41.1) 146 (35.8) Cause of death* n=100 n=44 n=144 LMWH treatment** 1# 0 1## Cancer 87 39 126 Sepsis 4 1 5 Bleeding 4 1 5 Antineoplastic treatment 1 0 1 PE 0 1 1 Other 7 3 10

*Multiple causes of death may have been reported in the same patient; **fatal bleeding reported as LMWH-related; #n=99;

## n=143

Kaplan-Meier estimate of the probability of bleeding at 6 months was 15.9% while corresponding estimates were 18.1% for thrombocytopenia and 34.5% for deaths. Of the five (3.5%) patients who reported fatal bleedings one was reported as related to the LMWH treatment. No heparin-induced thrombocytopenia was reported in the study.

Conclusion

Clinical outcomes were consistent with previous observations in this patient population except a lower incidence of VTE recurrence compared with previous studies. Study results tend to confirm the favorable efficacy and safety profile of LMWH for the long-term treatment of patients with cancer-associated VTE, when used according to recommended treatment duration and respecting contra-indications. Schulman. J Throm Haemost. 2005 Apr;3(4):692-4.Farge J Thromb Haemost. 2013 Jan;11(1):56-70.Debourdeau P, J Thromb Haemost. 2013 Jan;11(1):71-80

Disclosures

Farge: Pfizer: Research Funding; LEO Pharma: Research Funding. Debourdeau:Pfizer: Research Funding; LEO Pharma: Research Funding. Cajfinger:Pfizer: Research Funding; LEO Pharma: Research Funding.