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Rivaroxaban for the treatment of deep vein thrombosis and ...

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3.3.2 Enoxaparin dose– EINSTEIN-DVT<br />

The dose <strong>of</strong> Enoxaparin used in <strong>the</strong> trial reflected American practice (1mg/kg bid) ra<strong>the</strong>r than UK<br />

practice (1.5mg/kg od). Again, <strong>the</strong> ERG clinical advisors do not feel that this would have a big impact<br />

on VTE recurrence; this is supported by clinical guidelines review evidence 14 <strong>and</strong> a Cochrane<br />

review 26 , though <strong>the</strong> Cochrane review does not rule out <strong>the</strong> possibility that once daily LMWH may be<br />

less effective. This could potentially disadvantage rivaroxaban.<br />

3.3.3 Treatment <strong>of</strong> patients with cancer – EINSTEIN-DVT<br />

UK guidelines recommend use <strong>of</strong> LMWH <strong>for</strong> patients with cancer. 11 Such a <strong>treatment</strong> regime was not<br />

incorporated into <strong>the</strong> EINSTEIN-DVT trial. Patients with cancer are likely to fare worse under<br />

LMWH/VKA <strong>treatment</strong> than under LMWH <strong>treatment</strong>, <strong>and</strong> <strong>the</strong>ir inclusion in <strong>the</strong> trial may<br />

disadvantage results <strong>for</strong> <strong>the</strong> whole comparator group, in comparison to normal practice in Engl<strong>and</strong><br />

<strong>and</strong> Wales. Xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx<br />

xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx<br />

xxxxxxxxxxxxxxxxxxxxxxxx.<br />

To address <strong>the</strong> issue <strong>of</strong> <strong>the</strong> comparative efficacy <strong>of</strong> rivaroxaban to LMWH in this group, an MTC has<br />

been attempted <strong>and</strong> is discussed elsewhere (sections 4.3 <strong>and</strong> 4.4).<br />

3.3.4 “No preventative <strong>the</strong>rapy” option listed in NICE scope.<br />

The scope produced by NICE lists “no preventative <strong>the</strong>rapy” as a comparator. The MS rejects this as a<br />

comparator on page 22, stating<br />

“...all known guidelines on <strong>the</strong> <strong>treatment</strong> <strong>of</strong> VTE/DVT recommend at least 3 months <strong>of</strong> anticoagulant<br />

<strong>the</strong>rapy. Placebo or no <strong>treatment</strong> is <strong>the</strong>re<strong>for</strong>e not an appropriate comparison <strong>for</strong> initial <strong>treatment</strong> <strong>of</strong><br />

DVT.”<br />

Communication between <strong>the</strong> ERG <strong>and</strong> NICE confirmed that this comparator was considered<br />

appropriate at <strong>the</strong> scoping workshop, though it is not clear whe<strong>the</strong>r this comparator was intended<br />

during <strong>the</strong> “initial <strong>treatment</strong> <strong>of</strong> DVT” stage as interpreted by <strong>the</strong> manufacturer. Indeed, to test<br />

rivaroxaban against “no preventative <strong>the</strong>rapy” in patients who are clearly indicated <strong>for</strong> anticoagulation<br />

would be unethical. The ERG feels it is more likely that this was intended as a long-term <strong>treatment</strong><br />

comparator, where <strong>the</strong> risk <strong>of</strong> bleeding may outweigh <strong>the</strong> benefits <strong>of</strong> anticoagulation (reduced VTEs).<br />

The ERG has <strong>the</strong>re<strong>for</strong>e considered whe<strong>the</strong>r comparison to “no preventative <strong>the</strong>rapy” could have been<br />

better addressed in <strong>the</strong> MS, given <strong>the</strong> available trial evidence:<br />

25<br />

Copyright 2012 Queen's Printer <strong>and</strong> Controller <strong>of</strong> HMSO. All rights reserved.

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