BACKGROUND
The approval of new immunotherapies has dramatically changed the
treatment landscape of metastatic melanoma. These survival gains come with
trade-offs in side effects and costs, as well as important considerations to
third-party payer systems, physicians, and patients.
OBJECTIVE
Develop a Markov model to determine the cost-effectiveness of
nivolumab, ipilimumab, and nivolumab-ipilimumab combination as first-line
therapy in metastatic melanoma while accounting for differential
effectiveness in PD-L1 positive and negative patients.
METHODS
A three-state Markov model (‘PD-L1 positive stable
disease’, ‘PD-L1 negative stable disease’, and
‘Progression and/or Death’) was developed using a US
societal perspective with a lifetime time horizon of 14.5 years. Transition
probabilities were calculated from progression-free survival data reported
in the CheckMate-067 trial. Costs were expressed in 2015 US dollars and were
determined using national sources. Adverse event (AE) management was
determined using immune-related AE (irAE) data from CheckMate-067, irAE
management guides for nivolumab and ipilimumab, and treatment guidelines.
Utilities were obtained from published literature, using melanoma-specific
studies when available, and were weighted based on incidence and duration of
irAEs. Base case, one-way sensitivity, and probabilistic sensitivity
analyses were conducted.
RESULTS
Nivolumab-ipilimumab combination therapy is not the cost effective
choice ($454,092 per progression-free quality-adjusted-life-year [PFQALY])
compared to nivolumab monotherapy in our base case analysis at a
willingness-to-pay threshold of $100,000/PFQALY. Both combination therapy
and nivolumab monotherapy were cost-effective choices compared to ipilimumab
monotherapy. PD-L1 positive status, utility of nivolumab and combination
therapy, and medication costs contributed the most uncertainty to the model.
In a population of 100% PD-L1 negative patients, nivolumab was still
the optimal treatment but combination therapy had an improved ICER of
$295,903/PFQALY. Combination therapy became dominated by nivolumab when
68% of the sample was PD-L1 positive. In addition, the cost of
ipilimumab would have to decrease to <$21,555 per dose for
combination therapy to have an ICER <$100,000/PFQALY, and to
<$19,151 (a 42% reduction) to be more cost-effective than
nivolumab monotherapy.
CONCLUSIONS
Nivolumab-ipilimumab combination therapy is not cost-effective
compared to nivolumab monotherapy, which is the most cost-effective option.
Professionals in managed care settings should consider the pharmacoeconomic
implications of these new immunotherapies as they make value-based formulary
decisions and future cost-effectiveness studies are completed.