Table 1Summary of the Manufacturer’s Economic Submission

Drug ProductonabotulinumtoxinA (Botox)
Study QuestionFrom the perspective of the public payer in Canada, what is the cost-utility of onabotulinumtoxinA as compared with best supportive care (BSC) for the prophylaxis of headache in adults who have failed three or more oral prophylactic medications?

The manufacturer also undertook a scenario analysis of onabotulinumtoxinA in the full Health Canada indication as per CDR guidelines.
Type of Economic EvaluationCost-utility analysis
Target PopulationAdults with CM, ≥ 15 HDPM with headache lasting 4 hours a day or longer) who have failed (i.e., lack of efficacy, intolerance or clinical contraindication) 3 or more prior oral prophylactic medications

As indicated above, the manufacturer undertook a scenario analysis of the full population — CM without treatment failure.
TreatmentonabotulinumtoxinA
OutcomeQALY
ComparatorsBSC (appears to be placebo + acute treatments)
PerspectivePublic payer
Time Horizon3 years
Manufacturer’s Results (Base Case)$28,940 per QALY (full indication population)
$25,470 per QALY (subpopulation)
Key Limitations and CDR Estimate(s)
  • The key limitation of the manufacturer’s economic submission is whether the submitted model presents a good representation of the chronic nature of the disease and expected treatment. The modelling of CM is based on assumptions regarding patients with EM continuing treatment with onabotulinumtoxinA, lack of clarity around discontinuation of treatment, use of a “30% reduction in headache days” stopping rule, and the choice of a 3-year time horizon for a chronic condition.
  • The costs associated with physician visits, drug administration, and drug acquisition for onabotulinumtoxinA were likely underestimated in the economic model, which bias the results in favour of onabotulinumtoxinA.
  • Given the limitations identified, the likely ICUR is uncertain. When accounting for more likely cost inputs, CDR calculated ICURs in the range of $42,000 to $47,000 per QALY.

BSC = best supportive care; CDR = CADTH Common Drug Review; CM = chronic migraine; EM = episodic migraine; HDPM = headache days per month; ICUR = incremental cost-utility ratio; QALY = quality-adjusted life-year.

From: EXECUTIVE SUMMARY OF THE PHARMACOECONOMIC SUBMISSION

Cover of OnabotulinumtoxinA for Injection (Botox)
OnabotulinumtoxinA for Injection (Botox): For the Prophylaxis of Headaches in Adults With Chronic Migraine (≥ 15 Days per Month With Headache Lasting 4 Hours a Day or Longer) [Internet].
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