Table 2 Commercial stage assumptions used for the Rett syndrome compound valuation
From: Financing repurposed drugs for rare diseases: a case study of Unravel Biosciences
 (a) Price and adoption rate assumptions | Lower bound | Base case | Upper bound | ||||
|---|---|---|---|---|---|---|---|
Annual price ($) | 30,000 | 40,000 | 50,000 | ||||
Adoption rate (peak, segment of 0–12 years) | 35% | 50% | 65% | ||||
(b) Commercial stage assumptions | |||||||
|---|---|---|---|---|---|---|---|
Period of exclusivity (U.S.) | 14.0 | ||||||
Cost of Goods Sold (COGS, % of sales) | 10% | ||||||
Selling, General, and Administrative Expenses (SG&A, % of sales) | 30% | ||||||
Research and Development (R&D, % of sales) | 5% | ||||||
SG&A as % of R&D at pre-revenue stage | 40% | ||||||
Tax rate | 20% | ||||||
Additional benefits | |||||||
Patent term (in years) | 20 | ||||||
Orphan drug exclusivity (in years) | 7 | ||||||
Likelihood/strength of IP protection | 100% | ||||||
Pediatric exclusivity (in years) | 0.5 | ||||||
Tax credit on R&D (up to Phase 3) | 25% | ||||||
Priority Review Voucher (pediatric designation) valuation ($, in millions) | 100 | ||||||
Year in which the Priority Review voucher is granted (second year of Phase 2) | 3 | ||||||
Financial assumptions | |||||||
Discount rate | \(13\%\) | ||||||
(c) Patient population by age (U.S.) | Women in U.S. (in thousands) | Rett syndrome prevalence (per 1000) | Total patients | ||||
|---|---|---|---|---|---|---|---|
0 to 12Â years | 25,770 | 0.125 | 3221 | ||||
12 to 24Â years | 25,313 | 0.120 | 3038 | ||||
24 to 48Â years | 51,749 | 0.115 | 5951 | ||||
48 to 85Â years | 64,090 | 0.060 | 3845 | ||||
Total | 166,922 | 0.096 | 16,055 | ||||
(d) Adoption rates by age group per year following FDA approval (base case) | 1 | 2 | 3 | 4 | 5 | 6 | 7 |
|---|---|---|---|---|---|---|---|
0–12 years | 16.67% | 33.33% | 50.00% | 50.00% | 50.00% | 50.00% | 50.00% |
12–24 years | 12.50% | 25.00% | 37.50% | 37.50% | 37.50% | 37.50% | 37.50% |
24–48 years | 8.33% | 16.67% | 25.00% | 25.00% | 25.00% | 25.00% | 25.00% |
48–85 years | 0.00% | 0.00% | 0.00% | 0.00% | 0.00% | 0.00% | 0.00% |
Total number of patients | 1412 | 2825 | 4237 | 4237 | 4237 | 4237 | 4237 |
Peak year | Year 3 (following FDA approval) | ||||||