Emiltatug ledadotin

No budget impact model, cost-effectiveness analysis, or health technology assessment of emiltatug ledadotin was identified, and no systemic therapy is approved for recurrent or metastatic ACC, so no approved comparator price is available. The public economic information for the product consists of acquisition terms, company forecasts disclosed in tender offer documents, company statements on the U.S. patient population, and third-party market research.

Day One Biopharmaceuticals acquired Mersana Therapeutics on January 6, 2026, for $25.00 per share in cash (approximately $129 million equity value at closing; aggregate cash paid approximately $128.8 million) plus one contingent value right (CVR) of up to $30.25 per share (approximately $156 million in aggregate), for a total deal value of up to approximately $285 million. The CVR milestones include $1.00 per share for FDA Breakthrough Therapy designation (deadline December 31, 2027), $4.00 for first dosing in a registrational trial in ACC-1 (December 31, 2027), $9.00 for FDA approval in ACC-1 (December 31, 2030), and $2.00, $4.00, and $6.00 for annual net sales of at least $100 million (by 2032), $200 million (by 2035), and $300 million (by 2037). Breakthrough Therapy designation was granted on May 12, 2026, for locally advanced, recurrent or metastatic ACC with solid histology or high-grade transformation. Servier completed its acquisition of Day One on April 23, 2026, at $21.50 per share (total equity value of approximately $2.5 billion); the announcement did not report a value for Emi-Le separately.

Mersana management forecasts prepared for the tender offer, risk-adjusted and limited to ACC-1 with direct U.S. sales and ex-U.S. licensing, projected no revenue through 2027, revenue of $145 million in 2028 rising to $230 million in 2042, $115 million in 2043, $57 million in 2044, and none in 2045. A discounted cash flow analysis of these forecasts (discount rates of 19% to 28%, no terminal value) implied an equity value of $8 to $11 per share, compared with the $25 upfront consideration. Before the acquisition, a third party proposed licensing Emi-Le for ACC-1 alone with a $35.0 million upfront payment, a $10.0 million technology transfer payment, development and regulatory milestones of $220.0 million to $280.0 million, sales milestones of up to $675.0 million, and royalties in the low to high teens.

Company documents state an annual U.S. ACC incidence of approximately 1,300 patients (frontline and relapsed ACC combined), with up to 40% of patients having the aggressive form; a Servier press release states that more than 200,000 people have ACC globally. A separate eligible U.S. population count for aggressive recurrent or metastatic ACC was not reported. Day One described a combined revenue opportunity of more than $1 billion across three indications, one of which is Emi-Le in ACC. Market research publishers estimated the ACC market at USD 178.2 million in the seven major markets in 2025 (IMARC Group; USD 278.0 million by 2036), USD 164.0 million in the seven major markets in 2023 (DelveInsight; USD 260.7 million by 2034), and USD 182.30 million globally in 2025 (Research and Markets; USD 268.56 million by 2031).

As pricing context, a study of 66 injectable cancer drugs reported a median monthly price of US$14,950 in 2023 and launch prices 120% higher for orphan than non-orphan drugs, and a review of U.S. cost-effectiveness evaluations of approved ADCs reported ICERs above $150,000 per QALY for most. The only ACC-specific economic evaluation identified addressed radiotherapy (IMRT plus carbon ion boost versus IMRT alone; 26,863 euros per life-year), not systemic therapy.