A financial perspective on the topical
`treatment of onychomycosis
`
`To the Editor: A recent article from the July 2015 issue
`of
`the JAAD described the results of phase-III
`studies of a novel topical treatment for onychomy-
`cosis,
`tavaborole solution (Kerydin, Sandoz Inc,
`Princeton, NJ)1. The randomized trials compared
`treatment with the boron-based solution to the
`vehicle control. Exclusion criteria were myriad,
`including involvement of more than 60% of the nail
`plate, a nail plate thicker than 3 mm,
`‘‘severe
`disease,’’ concurrent tinea pedis, a history of chronic
`tinea pedis, known immunosuppression, peripheral
`vascular disease, and diabetes mellitus with A1C
`[8%. Despite these generous exclusion criteria, after
`48 weeks of daily therapy, the primary end-point of
`complete cure was achieved in only 6.5% of patients
`versus 0.5% treated with the placebo (study 1) and
`9.1% versus 1.5% for the placebo group (study 2). A
`similar study published in the April 2013 issue of the
`JAAD reported the results of phase-III trials of topical
`efinaconazole solution (Jublia) for onychomycosis.2
`Daily treatment for 48 weeks with efinaconazole
`achieved a complete cure rate of 17.8% versus 3.3%
`for placebo (study 1) and 15.2% versus 5.5% for
`placebo (study 2).
`I found it enlightening to consider these efficacy
`statistics from the perspective of number needed to
`treat (NNT) and associated cost. Averaging the 2
`tavaborole trials results in a combined efficacy of
`7.8% or, expressed as NNT, 12.8 individuals would
`have to complete 48 weeks of daily tavaborole
`therapy for every expected cure. A 10 mL monthly
`supply of tavaborole costs $1253.40 (or $13,787.40
`for the 11-month treatment course).3 Multiplying
`these two values (12.8 3 $13,787.40) reveals that,
`when using tavaborole, each successfully treated
`case
`of
`onychomycosis
`costs
`a
`predicted
`$176,478.72. The combined cure rate for efinacona-
`zole is 16.5%, or 6 when expressed in terms of NNT.
`An 8 mL monthly supply of efinaconazole costs
`$1,098.49 (or $12,083.39 for the 48-week treatment
`
`course).3 The product of these values reveals an
`expected cost of $72,500.34 for each patient suc-
`cessfully treated with efinaconazole.
`Admittedly, this ‘‘back of the napkin’’ analysis is
`not without
`shortcomings;
`it
`lacks
`sensitivity
`analyses as well as confidence intervals around the
`NNT, and there are well-documented concerns
`regarding ‘‘averaging’’ the results of clinical trials.4
`Nevertheless, in this era of cost-conscious medicine,
`the prospect of spending 3-7 times the American
`median annual personal income to cure a single case
`of onychomycosis does not seem to represent an
`appropriate use of resources.
`
`James Prewitt Lagrew, MD
`
`Department of Dermatology and Dermatologic
`Surgery, Medical University of South Carolina,
`Charleston, SC
`
`Funding sources: None.
`
`Conflict of interest: None declared.
`
`James Prewitt Lagrew, MD,
`Correspondence to:
`Department of Dermatology and Dermatologic
`Surgery, Medical University of South Carolina,
`135 Rutledge Ave, Charleston, SC 29425
`
`E-mail: lagrew@musc.edu
`
`REFERENCES
`1. Elewski BE, Aly R, Baldwin SL, et al. Efficacy and safety of
`tavaborole topical solution, 5%, a novel boron based antifungal
`agen for the treatment of toenail onychomycosis: Results from
`2 randomized phase-III studies. J Am Acad Dermatol. 2015;73:
`62-69.
`2. Elewski BE, Rich P, Pollak R, et al. Efinaconazole 10% solution in
`the treatment of
`toenail onychomycosis: Two phase III
`randomized, double-blind studies. J Am Acad
`multicenter,
`Dermatol. 2013;68:600-608.
`3. GoodRx.com, accessed September 30, 2015.
`4. Katz KA, Kim CY, Williams HC. Reporting clinical trials: why one
`plus one does not equal two. J Am Acad Dermatol. 2009;61:
`1082-1083.
`
`http://dx.doi.org/10.1016/j.jaad.2015.11.053
`
`J AM ACAD DERMATOL
`
`JULY 2016 e37
`
`ACRUX DDS PTY LTD. et al.
`
`EXHIBIT 1629
`
`IPR Petition for
`
`U.S. Patent No. 7,214,506
`
`Page 1 of 1
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