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

5.2.5 Conclusion of the economic section
The manufacturer reported that rivaroxaban was dominant in patients treated for 3, 6 or 12 months.
However, in the PSA undertaken using the manufacturer’s assumptions, the ERG found that
rivaroxaban was not dominant in patients with an intended treatment duration of 3 months; these had
an ICER of £11,792 per QALY yielded (after model correction). Rivaroxaban remained dominant
(providing more QALYs at a lower cost) compared with LMWH/VKA in the PSA in patients treated
for 6 and 12 months.
The ERG believes that assumptions made by the manufacturer to be plausible, however, other
plausible assumptions exist, given the uncertainties within the decision problem which may impact
the ICER.
The ERG explored other plausible scenarios amending the assumptions on INR monitoring and
allowed the proportion of VTEs that are PEs to differ between the treatment arms. For patients with
an intended treatment duration of 3 months, the ICER for rivaroxaban was always below £12,000 per
QALY yielded. For patients with an intended treatment duration of 6 months, the ICER for
rivaroxaban was labile, and could conceivable by either dominant or dominated. For patients with an
intended treatment duration of 12 months, the ICER for rivaroxaban was always below £15,000 per
QALY gained.
A simplistic cost minimisation analysis was undertaken to inform the appraisal committee of the
cheapest intervention. This was dual LMWH/VKA treatment for those with an intended treatment
duration 12 months, but was inconclusive at 3 and 6 months treatment duration as the results were
dependent on the assumed INR monitoring costs
The ERG note that other assumptions may impact the ICER such as assuming the proportion of major
bleeds that are IC bleeds are independent of treatment, and assuming that the risks of events after
treatment cessation is independent of treatment. The impact of these assumptions has not been
explored due to the absence of robust data.
It is noted that the manufacturer did not present an analysis for patients treated beyond 12 months, and
only considered the use of rivaroxaban for the treatment of the index event; it is unclear why
rivaroxaban was not considered for the treatment of the subsequent recurrences.
The manufacturer presented an exploratory analysis in the cancer subgroup of patients following a
request from the ERG. The ERG has concerns with this analysis and the validity of results presented
by the manufacturer. The ERG did not find the analysis robust.
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