Healthcare · Biotech
Biotech Partnership Economics
Biotech profit-share deals: Regeneron's $5.2B profit share against Sanofi's $17.8B of Dupixent global sales, and rNPV on economic share, not partner gross.
Selborne Research · Biotech coverage: 7 guides, 6 company profiles, a primer and Excel model
Educational analysis for professional use. This guide is not investment advice or a recommendation to buy or sell any security, and it is not personalised.
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Partner Gross Sales Are Not Your Revenue
Many antibody biotechs sell through alliances: one party records global product sales, the other books a profit share or royalty. Paste the partner’s gross sales into the biotech’s income statement and revenue, margins and franchise concentration are all overstated. Model the share the biotech itself recognises.
The standard example is Dupixent, an antibody for eczema and asthma that Regeneron and Sanofi developed together: $17.8B of global sales on Sanofi’s books against a $5.2B profit share for Regeneron in FY2025.
Dupixent: Two Books, One Product
| Metric | Sanofi-recorded | Regeneron-recorded | Period |
|---|---|---|---|
| Dupixent global net sales | $17.8B (+26% YoY) | N/A (partner line) | FY2025 |
| Regeneron share of Dupixent and Kevzara profits | N/A | $5,242M | FY2025 |
| Regeneron total revenue | N/A | $14,342.9M | FY2025 |
| Profit share as % of REGN revenue | N/A | 36.5% | FY2025 |
The profit-share line also covers Kevzara, a rheumatoid arthritis drug from the same alliance, but Dupixent was about 97% of the two products’ FY2025 sales. Regeneron sells Eylea, for eye disease, and other drugs of its own, so Dupixent is material without dominating. Vertex’s cystic fibrosis drugs, by contrast, are 92.9% of its revenue.
Worked Example: The 3.4x Overstatement
An analyst building Regeneron’s FY2025 revenue enters Dupixent at the partner’s gross figure:
| Build approach | Dupixent line | Error |
|---|---|---|
| Wrong: Sanofi global net sales | $17,800M | Treats partner revenue as REGN revenue |
| Correct: Regeneron profit share | $5,242M | Matches FY2025 filing |
| Overstatement ratio | $17,800M ÷ $5,242M = ~3.4x |
Swapping $5.2B for $17.8B adds ~$12.6B of sales Regeneron never booked, close to nine-tenths of its reported revenue of $14,342.9M.
Margins go wrong too. The profit share arrives with the shared costs already taken out, so applying a normal product margin to it counts those costs twice. The collaboration note in the 10-K gives the split.
Partnership Structures and rNPV
A pipeline drug is valued with a risk-adjusted NPV (rNPV): its cash flows weighted by the probability of success (PoS), the odds of getting from its current trial phase to approval. On a partnered asset, those cash flows are the biotech’s share of profits, never 100% of global sales:
| Input | Wholly owned asset | Profit-share partner asset |
|---|---|---|
| Revenue base | 100% of net sales | Contractual profit share % |
| Peak-sales estimate | Company or analyst estimate | Apply share to estimate |
| PoS | Phase transitions from current stage | Same PoS chain |
| Cash runway | Biotech liquidity ÷ biotech burn | Same; partner balance sheet is separate |
Peak-sales targets date quickly. Sanofi’s latest, at its Q2 2026 results on 30 July 2026, is around €25B of Dupixent sales in 2030 at constant exchange rates. Whatever the target, Regeneron’s exposure comes through the profit share.
Amgen: Diversification Instead of Collaboration
Amgen shows the other route. FY2025 revenue was $36.8B, and its largest product, the osteoporosis drug Prolia, brought in $4.4B (12.0%). Its obesity drug MariTide, in Phase 3 in 2026, is wholly owned, so its rNPV takes the full cash flows. See Amgen and Regeneron.
Checklist Before Modelling a Partnership
Read the collaboration note in the 10-K before touching revenue:
- Who records gross sales? Partner, biotech, or split by territory.
- What line does the biotech file? Profit share, royalty, or co-promotion reimbursement.
- Does concentration use the economic share? Measure Regeneron’s concentration on its profit share, 36.5% of revenue, not on Sanofi’s $17.8B of sales.
- How are milestones treated? Upfront and phase payments need separate treatment from the profit share. They add cash and buy time, but they do not cut operating burn unless the deal covers internal costs, so runway still comes from the biotech’s own cash flow statement.
A clinical-stage company's two programmes are valued year by year and its cash rolled forward to first sales, beside a franchise owner valued through its patent cliff.
- 15 sections, the clinical stage ladder to cash runway, multi-programme rNPV and a patent cliff
- 41 pages
- a two-programme clinical-stage company with its runway and dilution, a concentrated franchise owner and a diversified profitable company
- 3 worked companies
- profitable franchise owners and a cash-burner, on filed concentration, cash and burn
- 6-company screen
The Excel model is the primer's rNPV engine live across 13 sheets: a phase-by-phase PoS chain on BIO 2011-2020 rates, from Phase I to Approved; three worked companies, each switchable between clinical and commercial mode and valued year by year over 20 years, with later-phase R&D weighted by the odds of reaching it; a valuation summary with franchise floors; a runway calculator that rolls real cash forward, shows when it runs out if the lead fails, and prices the dilution from the raise; concentration and patent-cliff views; and a sensitivity grid. Change PoS, peak sales, R&D or the discount rate and the value moves.
See what's in the Biotech Sector Primer →£25 PDF · £59 with the Excel model · £159 for all three Healthcare industries
Frequently Asked Questions
- How do biotech antibody partnerships record revenue?
- It depends on the contract. In a profit-share arrangement, the partner often records global product sales while the biotech books its contractual share of collaboration profits. Regeneron recognised $5,242M as its share of Dupixent and Kevzara profits in FY2025; Sanofi recorded $17.8B of Dupixent global net sales.
- What is the Dupixent booking trap?
- Analysts who plug Sanofi's $17.8B Dupixent global net sales into a Regeneron revenue build overstate Regeneron's economic exposure by roughly 3.4x. Regeneron's FY2025 total revenue was $14,342.9M; its share of Dupixent and Kevzara profits was $5,242M (36.5% of revenue).
- How do partnerships affect rNPV?
- Profit-share deals split commercial cash flows by contract. A risk-adjusted NPV (rNPV) on a partnered asset uses the biotech's share of forecast profits, not gross partner sales. Milestone and royalty terms convert to the same share basis before discounting.
- Do large-cap biotechs still use partnerships?
- Yes, even at scale. Regeneron ($14.3B FY2025 revenue) shares Dupixent with Sanofi, which records global sales, while Regeneron books a share of the profits. Amgen ($36.8B revenue) uses licences and collaborations alongside wholly owned products like Prolia ($4.4B).
Read next
Biotech Franchise Concentration
Lead-franchise revenue share for biotech: Vertex cystic fibrosis 92.9%, Gilead HIV 70.5%, Moderna COVID 93.1%; growing versus shrinking franchises and partnership booking traps.
rNPV for Clinical-Stage Biotech
Single-asset rNPV for clinical biotech: PoS-weighted cash flows at 10.0–10.5% discount, a Phase II worked example at 15.1% PoS, equity equals rNPV plus net cash.
See it applied
These company profiles apply the concepts from this guide to real public companies.