Patent Expiry Reality: $4B at Risk by 2026
Pfizer’s 2025-2026 calendar has an unmissable number: over $4 billion in annual sales at risk as Enbrel and Humira see the last of their patent protections. Enbrel’s US exclusivity, once locked through 2029 by an aggressive defense, is now vulnerable after the Supreme Court declined to review Sandoz’s latest bid, so legal and regulatory pressure is building. Humira, which Pfizer markets outside the US, finds itself under biosimilar attack in Europe and emerging markets. The company’s internal forecasts paint a clear picture: combined global revenue from the pair is on track to fall by more than half between 2023 and 2027, plunging from about $4.3 billion to just north of $2 billion.
And this isn’t merely a headline risk. For Pfizer, which has relied on sticky legacy biologic sales for a decade, the revenue cliff is immediate and real. Earnings padding is about to get a jolt. This kind of swing doesn’t just shuffle the P&L; it shapes how R&D budgets get allocated, where M&A dollars get pointed, and how commercial units reprice risk. Unlike the one-off boom from COVID vaccines, these legacy drugs have been baseline products. The ones payers and PBMs build into their cost models year after year. Hospital systems expected them. And now, suddenly, they’ll have to plan again.
The Biosimilar Gambit: Growth Lever or Just Lower Margins?
During recent pipeline updates, Pfizer positioned biosimilars right at the center of its post-patent-cliff strategy. The rationale? The numbers are too big to ignore. In the US, biosimilars broke $11 billion in sales for the first time last year, per RxInfo.ai, and they’re gaining ground on traditional generics in Europe. Pfizer’s biosimilar suite, think infliximab (Inflectra), trastuzumab (Trazimera), bevacizumab (Zirabev), already tallies about $2 billion globally. With next-wave launches targeting adalimumab (Humira), etanercept (Enbrel), and denosumab (Prolia/Xgeva), management is targeting a doubling of biosimilar revenue by 2027. The plan: offset the top-line pain of dwindling exclusivities.
But the economics aren’t nearly as friendly. Biosimilars almost never match the gross margins of their branded predecessors. Enbrel and Humira once delivered fat EBITDA margins, 40-50%, with little competition and high net pricing. Biosimilar launches? They often limp in at mid-20% margins, forced lower by rebate wars and the arm-wrestling over formulary placement. In Europe, adalimumab biosimilars have already collapsed net prices by 60% versus the original. The situation in the US isn’t much rosier: Amgen’s Amjevita entered first, but a wave of competitors quickly undercut pricing, and the PBM contracting environment kept things unpredictable. Slow ramp, deep discounts. Not the stuff of easy wins.
Pfizer is no stranger to these market dynamics. Inflectra, its biosimilar to Remicade, famously missed early revenue forecasts when J&J’s reference product clung to major formularies longer than expected, and price erosion moved even faster than Pfizer’s models. The lesson: biosimilars can fill revenue headlines, but the earnings quality is a step down from the good old days. So for every $1 billion Pfizer loses on Enbrel or Humira, it realistically needs $1.5-2 billion in biosimilar sales just to keep margins from slipping.
Pfizer's Hedge: Beyond Biosimilars, Targeting Breadth and Scale
Inside the biosimilars division, the strategy now revolves around diversification and global leverage. Five pipeline products are set for launch by 2026, ustekinumab and eculizumab among them, both high-volume, defensible targets. What’s more, Pfizer has pushed investment into next-gen manufacturing technologies: continuous perfusion, single-use bioreactors, and other process upgrades. The goal: squeeze out a few more margin points wherever possible. But the real differentiator might be synergy, bundled discounts across their oncology and immunology biosimilars. If Pfizer can get major hospital groups or PBMs to buy in at the portfolio level rather than drug by drug, it stands a chance of carving out a more secure position. Of course, it all hangs on whether payers see portfolio aggregation as valuable. Or, honestly, whether procurement remains as fragmented as it has for years.
Internationally, the story changes. Pfizer is doubling down in price-sensitive markets: Brazil, China, and elsewhere, where the company is undercutting incumbents by 30% or more on trastuzumab and bevacizumab. Recent contract wins suggest there’s volume to be had, but each deal drags margins down a little further. According to management, ex-US biosimilars should make up 45% of the division’s sales by 2027, up from just 28% right now. That’s a clear decision: pursue scale, accept margin pressure, and hope that improved operational efficiency can offset the drag. If not, biosimilars risk turning into a volume game without a lot of profit at the end.
Next $4B: Can Earnings Keep Up With Lost Exclusivity?
What happens after the legacy cash flows shrink? Pfizer needs to somehow replace over $2 billion in annual operating profit, just to stay even. A tough ask. Especially when margin compression is inherent in the biosimilar transition, and the history so far, Amgen comes to mind, suggests gross margins below 30% for even the best players. Look at the forecasts: Pfizer points to $4 billion in new biosimilar revenue by 2027, but at 25-28% operating margins. Crunch the numbers. There’s still a profit gap, even if all goes as planned.
So the company is spreading its bets. Pipeline assets outside biosimilars, oral GLP-1s, targeted oncology programs, are supposed to help close what’s left. Whether those launches come fast enough is the billion-dollar question. The next 24 months are a crucible for Pfizer: will it dodge the fate that’s hit so many late-cycle biopharma giants, or just trade away margins for the sake of a pretty revenue line? The answer isn’t in the press releases. It’ll show up, quietly, first in the quarterly blur of line items. Or buried in real-world price data from RxInfo.ai and RxPBM.ai, the datasets that reveal where market share and net pricing are actually shifting as biosimilars flood in.
Specialty pharmacists and employer payers might want to brace for some odd swings in reimbursement, as rebating dynamics go haywire with each biosimilar launch. And investors? The core issue comes down to this: not whether biosimilars can match the dollar volume of their predecessors, but if they can possibly match the impact those old brands had on the bottom line. Most of the available data, and Pfizer’s own outlook, say it’s a stretch. The revenue can be made up. The earnings? That part is a harder sell, and I wouldn’t bet my own bonus on it.
