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

In the economic model, the manufacturer assumed patients to be treated for three, six or twelve
months according to the intended treatment duration observed in the EINSTEIN-DVT clinical trial. 50
The ERG sought clinical opinion on the validity of the intended treatment duration used in the trial
and how this reflects UK clinical practice. Clinicians agreed that in clinical practice, patients would be
treated for three, six months or for a longer treatment period. However, our experts did not share the
view that cessation of treatment at 12 months is common in the UK, and suggested that clinical
practice has changed in recent years and that there is a group of patients which are more likely to be
treated on an ongoing basis if clinical characteristics and risk factors indicate that this is appropriate.
Our experts also believed that those who were assigned to the 12 months treatment group in the
EINSTEIN-DVT trial 50 could be considered a surrogate for patients who may receive treatment on an
ongoing basis in clinical practice.
The manufacturer was contacted and clarification was requested on the reasons why no analysis was
performed in patients treated on an ongoing basis. 17 The manufacturer did not provide such analysis
as the manufacturer did not agree with the view expressed by our clinicians, and did not consider
treatment longer than 12 months to be common. The manufacturer’s argument, however, centres
around patients experiencing their first DVT, and in this context, the view that few go on to long term
treatment may be more accurate. However, the population of interest to this assessment is
symptomatic DVT, whether it is a recurrence or a first event. The ERG clinicians are of the opinion
that up to 20% of VTE patients experiencing their first DVT or a recurrence of a DVT would go on to
receive ongoing treatment.
The ERG acknowledges the responses from the manufacturer and the absence of data for patients
treated on an ongoing basis, but disagrees with the statement from the manufacturer that this group
does not exist. The ERG would have liked to see an exploratory analysis examining the effect of
ongoing treatment on the ICER, acknowledging that such analysis would rely on further assumptions.
5.2.1.4 Intervention
The economic model considered the use of rivaroxaban (Xarelto®) according to its license indication,
i.e. 15 mg twice a day for 21 days, followed by 20 mg once a day for the remaining duration of
anticoagulation treatment. 52,53
5.2.1.5 Comparators
The comparator for the main analysis is dual therapy LMWH/VKA as defined by NICE in the scope. 3
The manufacturer 1 stated that there are four LMWH treatments licensed for the treatment of DVTs or
PEs; Fragmin® (dalteparin sodium), Clexane® (enoxaparin sodium), Innohep® (tinzaparin sodium)
and Zibor® (bemiparin sodium).
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