OBJECTIVE: To evaluate the cost effectiveness of dabrafenib versus dacarbazine 
and vemurafenib as first-line treatments in patients with BRAF V600 
mutation-positive unresectable or metastatic melanoma from a Canadian healthcare 
system perspective.
METHODS: A partitioned-survival analysis model with three mutually exclusive 
health states (pre-progression, post-progression, and dead) was used. The 
proportion of patients in each state was calculated using survival distributions 
for progression-free and overall survival derived from pivotal trials of 
dabrafenib and vemurafenib. For each treatment, expected progression-free, 
post-progression, overall, and quality-adjusted life-years (QALYs), and costs 
were calculated. Costs were based on list prices, a clinician survey, and 
published sources. A 5-year time horizon was used in the base case. Costs (in 
2012 Canadian dollars [CA$]) and QALYs were discounted at 5% annually. 
Deterministic and probabilistic sensitivity analyses were conducted.
RESULTS: Dabrafenib was estimated to yield 0.2055 more QALYs at higher cost than 
dacarbazine. The incremental cost-effectiveness ratio was CA$363,136/QALY. In 
probabilistic sensitivity analyses, at a threshold of CA$200,000/QALY, there was 
an 8.2% probability that dabrafenib is cost effective versus dacarbazine. In 
deterministic sensitivity analyses, cost effectiveness was sensitive to survival 
distributions, utilities, and time horizon, with the hazard ratio for overall 
survival for dabrafenib versus dacarbazine being the most sensitive parameter. 
Assuming a class effect for efficacy of BRAF inhibitors, dabrafenib was dominant 
versus vemurafenib (less costly, equally effective), reflecting its assumed 
lower daily cost. Assuming no class effect, dabrafenib yielded 0.0486 more QALYs 
than vemurafenib.
CONCLUSIONS: At a threshold of CA$200,000/QALY, dabrafenib is unlikely to be 
cost effective compared with dacarbazine. It is not possible to make reliable 
conclusions regarding the relative cost effectiveness of dabrafenib versus 
vemurafenib based on available information.