Sanofi paid $74 a share for Genzyme, then $315 million more to settle the fight over the part it didn't pay

In February 2011, two companies stood across a table with a signed price and one unsolved problem. Sanofi would pay $74.00 in cash for every Genzyme share.¹ What it would pay for Lemtrada — an experimental multiple-sclerosis drug Genzyme swore was worth billions and Sanofi wasn't so sure about — nobody could agree on. So they did what dealmakers do when the number won't sit still: they stopped trying to name it. Instead of folding Lemtrada's value into the price, Sanofi handed every shareholder a slip of paper — a contingent value right — that would pay out only if the drug delivered.⁵ The disagreement didn't get resolved. It got deferred, packaged, and passed to the sellers as a bet.

The official story is that this was elegant deal engineering: a clean cash price for the certain part, a market-traded instrument for the uncertain part, everyone paid for exactly what they got. The real story is that a CVR doesn't make disagreement disappear. It just changes the room the disagreement gets settled in — and Sanofi's ended up in a courtroom.

The fork: name a price both sides doubt, or make the sellers bet on the drug: a CVR looks like a compromise, but it is really a transfer of who carries the uncertainty

Every acquisition contains a valuation the two sides secretly dispute. Usually one side blinks and a single number gets written down. The Genzyme deal is instructive because both sides refused to blink on the same asset — and then found a mechanism that let neither of them have to. Sanofi and Genzyme could not agree on what Lemtrada was worth, so Sanofi issued one CVR per share instead of pricing the drug into the headline offer.⁵ Read that plainly: the CVR exists precisely because the deal couldn't be closed without it. It wasn't a bonus. It was the load-bearing beam that held two irreconcilable valuations up at once.

The CVRs weren't confetti. Each one entitled the holder to real cash if Lemtrada cleared specific hurdles — including $3.00 per CVR if the drug's global net sales cleared $2.8 billion — with the whole instrument set to terminate at the end of 2020, or sooner if the final sales milestone hit.² And the market believed in the bet. Shortly after closing, Sanofi's own annual filing recorded the CVRs trading at $2.35 apiece — $685 million in aggregate value that Sanofi had to book as contingent consideration.⁴ So the popular idea that the CVR was a worthless token from day one is simply wrong. On day one it was a $685 million promise the market took seriously. It only became worthless later, one missed deadline at a time.

One deadline did the whole instrument in: the CVR wasn't a soft aspiration — it was a lattice of hard dates, and a hard date is a thing you can miss

Here is the mechanism that turns a clever structure into a liability. A CVR that pays on milestones is only as clean as the milestones are clear — and clear milestones are, by construction, missable. Buried in the agreement was a specific requirement: Sanofi had to secure FDA approval for Lemtrada on or before March 31, 2014, on top of later sales thresholds.⁸ That date came and went without approval on the required timeline. And the contract had spelled out, in advance, exactly what happens then: if the milestones weren't achieved 'for any reason' within the specified periods, no payment would be made and the CVRs would expire valueless.³ The instrument was designed to have a hard off switch. The switch got flipped.

When a footnote grows teeth: a milestone you control invites the accusation that you controlled it against the people you owe

This is where the structure quietly reverses on its author. The moment Lemtrada's approval slipped past the March 2014 deadline, the CVR holders had both a grievance and a suspicion — because Sanofi controlled the very effort the milestone depended on. Former Genzyme shareholders sued, alleging Sanofi had intentionally delayed the approval, including ignoring FDA concerns about the trial design, to dodge a roughly $708 million payout obligation.⁶ The suit's spine was a specific covenant: that Sanofi had promised to use diligent, commercially reasonable efforts to hit the regulatory and sales milestones, and had breached it.⁸ Note what that means. The CVR didn't just create a payout condition. It created a duty — a legally enforceable obligation to try — and a duty is something a court can find you violated.

In 2019, Sanofi settled for more than $315 million, without admitting wrongdoing.⁷ So the fork Sanofi chose in 2011 — bet the sellers on the drug rather than price it in — cost real cash after all. Not the $708 million the plaintiffs claimed; roughly half that. But the point isn't the arithmetic. The point is that the risk Sanofi thought it had exported to shareholders came home. The CVR didn't eliminate the Lemtrada valuation dispute. It relocated it from the negotiating table, where it was solvable with a number, to a courtroom, where it was solvable only with a check.

Wasn't the CVR still the right call?: the honest defense is that it got the deal done at all — and a $315 million settlement may beat overpaying upfront

The fair objection is that without the CVR there might have been no deal. If Sanofi and Genzyme genuinely could not agree on Lemtrada's value, the CVR wasn't a trick — it was the bridge that let a $20-billion-plus acquisition close instead of collapsing.⁵ And on strict math, the structure arguably worked: had Sanofi priced Lemtrada into the headline offer at anything like what Genzyme believed it was worth, the overpayment could have dwarfed a $315 million settlement paid eight years later in cheaper, later dollars.⁷ The CVR shifted risk to the party best positioned to accept it — sellers who believed in their own drug — and let Sanofi pay for optimism only if the optimism was borne out. That's textbook risk allocation, and it's a real defense.

But the defense concedes the thesis rather than refuting it. The CVR was cheaper than overpaying only because Sanofi later spent years and hundreds of millions defending it — and it never made the underlying disagreement go away, it just deferred the bill and added lawyers to the invoice. A structure that 'saves money' by converting a valuation argument into a fiduciary-duty lawsuit hasn't priced the risk. It has repriced it, in litigation, on terms it no longer controls. The elegant footnote grew teeth precisely because the milestone depended on Sanofi's own effort — and any time your payout obligation shrinks when you drag your feet, someone will accuse you of dragging your feet.

Sanofi got its clean headline: $74.00 a share, a single number to announce, the Lemtrada argument tucked neatly into a tradable slip. For a while it even looked free — a $685 million promise that would cost nothing if the drug fell short. But a milestone you control is a milestone you can be sued over, and a valuation you defer is a valuation you'll argue about later at a worse time in a worse room. The CVR didn't erase the disagreement over what one drug was worth. It just made sure that when the answer finally arrived, it came with a docket number and a settlement Sanofi still had to pay.