Not every biotech collaboration locks both sides into a single economic model at signing. Sophisticated agreements increasingly contain switches — rights that let one partner choose, at a defined moment, between fundamentally different ways of being paid or of committing capital. Two of the most common are the profit-share opt-in and the option-to-license. Both are tools for managing the central problem of early-stage biotech deals: how to allocate risk and control over an asset whose value is still uncertain.

Take the profit-share opt-in first. In a standard out-license, the licensor receives milestones and royalties and the licensee bears the costs and keeps the profits. A profit-share opt-in adds an alternative: the licensor can elect, for a designated program, to share the profits and the costs of commercialization instead of taking the royalty path. Choosing the profit share means giving up the milestone-and-royalty stream for that program and instead splitting net profits (and funding a share of the spend) — trading a lower-risk, capped royalty for a higher-risk, higher-upside, higher-cost position. A real, SEC-filed collaboration states the mechanism precisely.

"Septerna has the right to opt-in to a worldwide profit-share for one program, in lieu of future milestones and royalties for that product candidate."— Septerna, Inc., Form 8-K Exhibit 99.1 (filed with the SEC), source

Three terms in that one sentence define the structure. It is a right ("the right to opt-in") — an option, not an obligation, so the partner can decline and keep the default royalty economics. It is scoped ("for one program") — the switch applies to a single, designated candidate, not the whole collaboration. And it is exclusive of the alternative ("in lieu of future milestones and royalties") — electing the profit share means surrendering the milestone-and-royalty path for that program. The choice is therefore a genuine fork: the same asset yields one economic profile if the partner stays on royalties and a different one if it opts into the profit share, and the partner gets to pick once it knows more.

Why a company would want the switch

The profit-share opt-in exists because the right answer is unknowable at signing. Royalties are simpler and lower-risk: the licensor collects a percentage of sales without funding commercialization or absorbing its losses. A profit share is the opposite trade — it requires putting capital in and accepting downside if the program underperforms, in exchange for a larger slice (and usually more commercial influence) if it succeeds. By deferring the choice to a later, data-informed moment, the agreement lets the partner pick the model that fits what the program has become, rather than betting on what it might become. The opt-in is, in effect, an embedded option on the partner's own conviction.

The option-to-license is the same logic applied one step earlier, to the licensing decision itself. Instead of in-licensing a candidate outright, a partner pays for the right to license it later — typically at a defined trigger such as a data readout — for a pre-agreed (or to-be-negotiated) set of terms. The partner pays a smaller amount now to keep the asset in view and defers the larger upfront and the full commitment until the option window opens. If the data disappoint, the partner can let the option lapse and walk away cheaply; if the data are strong, it exercises and the full license economics kick in. The structure converts a binary "license now or not" decision into a staged one, pricing the cost of waiting explicitly.

How these structures are disclosed

It helps to see how these two switches differ in timing and in what they cost. A profit-share opt-in is usually exercised after a program is already inside the collaboration and advancing, and its "cost" is the obligation to start funding a share of the program's spend in exchange for a share of its profits. An option-to-license is exercised before a candidate is fully in-licensed, and its cost is an explicit option fee (sometimes plus a later exercise payment) paid for the right to decide. Both also reshape the recipient's financial profile in ways a reader should anticipate: electing a profit share converts a company from a royalty recipient into a co-funder, putting program costs onto its own income statement; exercising an option converts a small option fee into the full upfront-and-milestone obligations of a license. Structures like these are increasingly common precisely because early biotech assets carry binary, data-dependent risk, and a switch lets the parties commit capital in proportion to what the data later show rather than all at once.

Because an opt-in or an option changes who bears risk and who controls a program, the right is a material term and is summarized in the collaboration's 8-K, as in the Septerna disclosure above, with the full mechanics — the trigger, the election deadline, the profit-and-cost split percentages, and the consequences of electing — set out in the collaboration agreement filed as an exhibit on sec.gov. As with royalty rates, specific split percentages and option fees may be redacted as confidential, but the existence and structure of the election are disclosed.

For a reader, the presence of an opt-in or option is a signal to look past the headline economics, because the headline assumes one branch of a fork that has not been chosen yet. A deal described as "milestones and royalties" may, by its own terms, become a profit-share for a key program — or an option may convert into a full license, or quietly expire. The disclosed terms tell you the choices exist and who holds them; the value of the deal depends on which branch is ultimately taken. That optionality is the feature these structures are built to provide, and it is written, election by election, into the agreement on sec.gov.