A 13.6% Top Line That Converts to 2.2% Operating Income: Currency, the Regeneron Split, and the 2031 Clock Take Sanofi's Quarter Back

Results vs. Consensus

Sanofi reports in euros on a per-ordinary-share basis; the SNY line is an American Depositary Share representing one-half of one ordinary share. Published US consensus is quoted per ADS in dollars. Both bases are shown below and no figure is converted between them.

Consensus for the two dollar lines is the published US number as of the print; the euro lines carry no comparable published consensus that could be verified as of the report date, so they are marked n/a and judged against the prior-year base and the company's own guidance instead. Business operating income was reported above the company-compiled European consensus, but the level of that consensus could not be verified and is therefore not printed here.

Year-over-Year: the Business (non-IFRS) P&L

The whole quarter is in the gap between the last two columns. Sales, gross profit, operating income and business EPS each grew at double digits in local currencies and single digits after translation, and the compression is not evenly spread: gross profit lost 8.3 points of growth to currency while operating expenses lost only 5.9, so the currency move worked against the mix. Below gross profit, the other operating expenses line did the rest of the damage, growing 43.9% as reported on a base that was already large.

Sequential: Q1 2026 vs. Q4 2025

The sequential table is the corrective to the headline margin. Sanofi's Q1 is structurally its richest quarter and Q4 its poorest: vaccines are a Q3 and Q4 business (they fell 36.6% sequentially), and research and selling costs carry year-end weight (R&D fell 23.7% sequentially, SG&A 15.3%). A 28.2% BOI margin against 20.7% in Q4 is seasonality doing most of the work, not a step-change in operating leverage. Anyone annualising the Q1 margin is annualising the wrong quarter.

The IFRS-to-Business Bridge

The Q1 2025 "other tax effects and other items" line is shown as the €22m that reconciles the filed column; the two published sub-lines for that period sum to €21m, a rounding difference inside the company's own table.

Revenue. Take the quarter at constant currency and this is a company with genuine momentum: 13.6% growth, the second consecutive quarter of double-digit constant-currency expansion after 13.3% in Q4, and a launch portfolio that grew 49.6% and now represents 14% of group sales including vaccine launches. The United States grew 26.2% and now accounts for 50.3% of sales. That is the good version of the story, and it is the version management told. The other version is that the reported line grew 6.2%, that Rest of World grew 0.2% and China shrank 2.1%, and that outside Dupixent and the launch cohort the base business is contracting: the residual portfolio of established medicines is roughly 36.9% of sales and is where Lovenox fell 22.3%, Alprolix fell 17.5%, the "others" line fell 13.7% and industrial sales fell 16.7%. Sanofi's growth is concentrated in fewer places each quarter.

Margins. The margin story is the one that should change how the quarter is modelled. Business gross margin at 77.9% is close to a structural high and the mix shift toward specialty and rare disease supports it. But the profit-sharing line sits below gross profit and it is growing faster than the product that generates it. Regeneron profit sharing was €1,514m against €1,115m, up 35.8%, while Dupixent grew 19.8% at actual rates. Every incremental euro of Dupixent is therefore worth less to Sanofi than the last, and the effect is large enough to have taken 1.1 points off the operating margin in a quarter where gross margin was flat and operating expenses fell as a percentage of sales. This is the single most important line in the model and it is the one management spent the least time on.

EPS. Business EPS of €1.88, up 14.0% at constant currency, is the number that will be quoted. It is also the number that most flatters the quarter: it carries the buyback, it excludes €650m of add-backs, and it is denominated in a currency assumption that the company itself expects to cost about 3% for the full year. On the reported IFRS line, which is the one that actually accrues to shareholders, earnings per share fell 11.8%. Both numbers are true. The distance between them is 26 points of growth, and it is worth being explicit that a European pharmaceutical with 51% dollar revenue exposure and a euro reporting currency will keep printing that distance for as long as the euro stays where it is.

Segment Performance

By geography

By franchise

Dupixent: €4,170m, +30.8% at CER, 39.7% of group sales

Dupixent cleared €4bn for the second consecutive quarter and grew 30.8% at constant currency, with the US up 35.9% to €3,023m, Europe up 22.4% to €563m and Rest of World up 14.9% to €584m. It is now approved in nine indications, following the February US approval in allergic fungal rhinosinusitis, and reaches more than 1.4 million patients. On a reported basis the number grew 19.8%, and sequentially it declined 1.8% from Q4's €4,246m.

Two qualifications matter. The first is the base: management said three separate times, in prepared remarks and twice in Q&A, that the US line benefited from a low comparison caused by high gross-to-net price adjustments a year ago.

"As you rightly pointed out, the Q1 performance partly reflects a low basis of comparison due to higher gross to net price adjustments in Q1 2025. But again, if you correct for that, the sales growth is largely driven by volume demand. You know that GTN fluctuates from quarter-to-quarter due to many different factors. Q1 in the US usually is highest because of the annual insurance benefit resetting."
— Manuela Buxo, Head of Specialty Care

The second is the trajectory management is guiding to. The company has been explicit that this rate does not persist.

"As shared previously, we anticipate volume-driven growth to continue with some normalization in the second half of the year as new launches annualize and comparisons are getting tougher."
— Olivier Charmeil, Interim CEO

Assessment: The demand signal is genuine, the market position is unchallenged and the indication expansion still has runway. What has changed is the economics. At 39.7% of group sales and with the profit-share line growing nearly twice as fast as the product at reported rates, Dupixent is simultaneously the reason to own Sanofi and the reason the operating margin is falling. A model that grows Dupixent without growing the Regeneron deduction faster will overstate every year to 2031.

Pharma launches: €1,171m, +49.6% at CER

ALTUVIIIO is the standout and is now the largest factor medicine in the haemophilia A market, with 83% of sales in the US and Rest of World approaching a fifth of the total on Japanese and Taiwanese launches. Combined with Eloctate the franchise grew 31.5%, so the switching is largely internal cannibalisation of a declining asset plus genuine share capture from competitors. Ayvakit at €177m is the acquired growth: management flagged that higher US government rebates now apply because Blueprint sits inside Sanofi, which cost roughly 10 points of growth on a market pro-forma basis.

"Higher government rebates as a result of the originator Blueprint becoming part of Sanofi had a negative impact on US sales."
— Q1 2026 results release

The interim CEO put the acquisition effect on the launch cohort plainly. Counting vaccines, the full launch portfolio reached €1,517m and grew 43.8% at constant currency, and management characterised that as roughly 44% including acquisitions and approximately 22% excluding them. The organic rate is the number to carry forward, and it is half the headline.

Assessment: A launch portfolio compounding in the low twenties organically, spread across eleven assets none of which exceeds €325m, is a healthy diversification engine but not yet a Dupixent replacement. At €1,171m a quarter it is 28% of Dupixent's €4,170m and would need to more than triple to fill the hole a 2031 erosion would open. Compounding at 22% a year, that takes roughly six and a half years, which lands after the March 2031 expiry rather than before it. That arithmetic is the core of our rating.

Vaccines: €1,293m, +2.1% at CER

The 2.1% headline conceals a genuinely weak underlying quarter. The PPH line grew 4.2%, but the US component grew 47.4% purely because Heplisav-B was consolidated from February while Rest of World fell 13.1% on lower demand from declining childbirths, including in China. Beyfortus grew 2.8% globally but fell 21.5% in the US against a Q1 2025 inventory build and, in management's own words, competition. Meningitis, travel and endemic fell 2.0% with the US down 17.5%. Growing a €1,293m segment by 2.1% is an increment of roughly €27m; the acquired Heplisav-B contributed €46m on its own, so the rest of the vaccine portfolio went backwards.

Assessment: This is the segment where the structural question is hardest to dismiss. Demographics are working against the paediatric franchise in the two largest volume markets, the RSV franchise now faces a competitor in its most profitable geography, and the response so far has been to buy adult immunisation rather than to fix paediatric. Heplisav-B is a sensible asset at a sensible price; it is also a €46m quarterly contribution against a €1.3bn segment that is flat.

Established portfolio: the funding source nobody discusses

Outside Dupixent, vaccines and the launch cohort, roughly 36.9% of sales sits in a portfolio that is in managed decline. Lovenox fell 22.3% on sustained biosimilar pressure, Alprolix fell 17.5%, Myozyme fell 13.3% as patients switch to Sanofi's own Nexviazyme, Aldurazyme fell 25.5%, Synvisc fell 30.9%, the "others" aggregate of €865m fell 13.7% and industrial sales of €81m fell 16.7%. Against that, Toujeo grew 10.5%, Praluent grew 17.7% and Fabrazyme grew 7.6%. Rest of World, where much of this portfolio sits, grew 0.2% in total.

Assessment: The decline here is orderly and largely self-inflicted through deliberate portfolio streamlining, which cost 0.4 points of growth in the quarter and is the right thing to do. But it means the reported growth rate is the difference between two large opposing forces, and it makes the group more dependent on Dupixent each quarter rather than less. The Medley divestment signed in March continues the direction of travel and will book below operating income at the earliest around the end of 2026.

Rare disease: €1.8bn, +20%

Management chose to give rare disease its own slide and its own framing this quarter, disclosing a franchise of nearly €1.8bn growing 20%, with launches contributing almost half of sales.

"In Q1, this business reached nearly EUR1.8 billion, and grew by 20%, led by Ayvakit and ALTUVIIIO. Our growth is fueled by innovation and by new launches, which contribute to almost half of sales."
— Olivier Charmeil, Interim CEO

Assessment: The elevation of rare disease to a named pillar, combined with the decision to house Blueprint inside it rather than inside immunology, is the clearest strategic signal in the quarter. It is also the area management named first when asked where business development capital would go. Read alongside a 2031 immunology cliff, this looks like the beginning of a deliberate rebalancing rather than a presentational choice.

Key Topics & Management Commentary

Overall Management Tone: Management was composed and well-rehearsed but conspicuously non-committal on the two questions the call kept returning to. The quarter's own numbers took a short section of the prepared remarks; a new life-cycle slide for Dupixent took the bulk of the Q&A, and every attempt to convert that slide into dates, partners or thresholds was met with a version of "we won't disclose more at this stage." The posture is that of a caretaker administration holding a line rather than a management team setting one, which is what an interim chief executive six days from an annual meeting would be expected to do.

1. The gap between constant-currency and reported growth is now the story

Sanofi reports in euros and earns 51.0% of its revenue in dollars. In Q1 the average euro/dollar rate moved from 1.053 to 1.171, an 11.2% swing, and the euro/yen rate moved 14.5%. The result is a 7.4-point translation drag on sales growth and a comparable drag on every line below it. The company's own published sensitivity puts a further 0.05 move in the dollar rate at €1,069m of sales and €0.23 of business EPS for the full year, and the guidance assumes roughly a 2% sales and 3% EPS headwind at April rates.

This is not a presentational quibble. Constant-currency growth measures the operating business; reported growth measures what accrues to a euro-denominated shareholder. In a quarter where those two numbers are 13.6% and 6.2%, the choice of which one to anchor on is the difference between a growth stock and a value stock.

Assessment: We anchor on reported. Sanofi does not hedge its translation exposure into a materially different outcome, the dollar weakness is not obviously transient, and the constant-currency series has now overstated the reported series by seven points for a full quarter. Modelling this business at its constant-currency growth rate is the single easiest way to be wrong about it.

2. Regeneron takes a growing cut of its own success

The other operating income and expense line is where the quarter was lost, and inside it the Regeneron alliance is the dominant term. Profit sharing was €1,514m against €1,115m a year ago, up 35.8%, while Dupixent grew 19.8% at actual rates. Net of the €303m development-cost share received from Regeneron and the €167m of selling expense reimbursed to Regeneron, the alliance cost Sanofi €1,378m against €1,062m. That single line is equivalent to 46% of business operating income.

The CFO named the driver but not its magnitude, and folded it in with a separate and unrelated item.

"BOI was up by 10.9% and BOI margin was slightly down due to higher profit sharing and the phasing of capital gains, which were approximately EUR230 million last year versus only EUR40 million this year."
— François-Xavier Roger, Chief Financial Officer

The capital-gain phasing is a genuine one-off worth about €190m, and adjusting for it alone would lift operating income growth from 2.2% to roughly 8.8% at actual rates. The profit-share escalation is not a one-off. It compounds with the product.

Assessment: The most under-modelled feature of this business is that Dupixent's economics to Sanofi deteriorate as Dupixent grows. Analysts building a Dupixent ramp to 2031 need to grow the profit-share deduction faster than the product, not proportionally, and the Q1 spread of 16 points between the two growth rates is a live data point on how much faster.

3. The R&D reimbursement step-down: about €400m this year, about €700m next

The single most useful disclosure of the call did not appear in the prepared remarks at all; it came out under questioning. Regeneron has been reimbursing Sanofi for a share of Dupixent development costs, and that balance is running out.

"So probably net around EUR400 million negative impact BOI this year and maybe EUR700 million next year negative again on the top of what we get this year."
— François-Xavier Roger, Chief Financial Officer

The CFO added timing and a commitment.

"We expect the balance to be fully reimbursed around Q2 2026. But obviously, this is the reason why it will have an impact on up to Q2 2027. You may remember as well that we said that in spite of that, our BOI will increase both in margin and in absolute value, both in '26 and '27."
— François-Xavier Roger, Chief Financial Officer

Note also that the €800m originally expected for 2027 was revised down to about €700m, and the reason given was that Dupixent is growing faster than planned, so the reimbursement balance is being consumed sooner. The headwind is being pulled forward, not reduced.

Assessment: Roughly €1.1bn of cumulative operating-income headwind across 2026 and 2027, against a FY25 business operating income base of €12,149m, is about 9% of that base to absorb over two years. Management has committed publicly to growing operating income in both absolute terms and margin regardless. That is a real, dated, gradeable commitment and it is the first thing we will mark next quarter.

4. Dupixent to 2031: defend, extend, innovate

The new slide sets out three pillars against the March 2031 US compound patent expiry: a patent portfolio with issued and pending expirations running from 2031 to 2045; a dosing extension to every four weeks via a higher dose in asthma and a co-formulation; and new molecules brought into the existing alliance infrastructure. The General Counsel's framing of the patent estate was the most confident statement on the call.

"So if and if we wanted to give clarity to our investors of the strength and even if we have people lining up to discuss. There is nobody at the moment because nobody has challenged our patents. Typically, this happens closer for biologics. This happens closer to launch."
— Roy Papatheodorou, EVP and General Counsel

The R&D head declined to rank the estate when pressed on which patents carry the extension.

"Picking one patent out of tens of patents is not a good testament to the amount of innovation we've done for Dupixent over the years. We have multiple strong patents going up to 2045. We believe we have a very strong patent portfolio and intend to seriously defend all of them."
— Houman Ashrafian, EVP and Head of R&D

Assessment: Both statements are accurate and neither is informative. "No one has challenged us" is a statement about the calendar, not about the strength of the estate; biosimilar filers do not challenge five years early. The absence of any dated milestone, any quantified erosion scenario and any settlement posture means the market is being asked to underwrite the 2031 outcome on management's confidence. At 39.7% of sales, that is too large a share of the company to take on faith, and it is the central reason we are at Hold rather than Outperform.

5. The every-four-weeks co-formulation: hyaluronidase, partner undisclosed, studies not started

The extension pillar rests on two mechanisms. The higher-dose route in asthma is already in development and management described its pathway as conventional. The co-formulation route is earlier and thinner.

"Yes, I can confirm that it is hyaluronidase with a partner. We won't disclose any more than that at this stage. And then on the second question, we don't disclose the milestones for internal decisions around the IL-4 receptor alpha."
— Houman Ashrafian, EVP and Head of R&D

What is known: the technology is precedented, it is partnered, clinical studies are expected to start in the second half of 2026, and management believes it will apply across the majority of Dupixent indications. What is not known: the partner, the economics, the completed formulation work, whether any data will be published, the regulatory pathway, or the launch date. Asked directly whether the co-formulation would generate new intellectual property, the answer was a single line about protecting every innovation and letting patient convenience define the objective.

Assessment: A hyaluronidase co-formulation is a well-trodden route and the probability of technical success is high. The commercial question is whether every-four-week dosing is a sufficient differentiator by 2031 against whatever the competitive set looks like then, and whether the new formulation patents survive the same challenge the compound patent will face. Management was asked both questions and answered neither. Studies that have not started in mid-2026 leave very little margin against a March 2031 date.

6. Amlitelimab, two Kaposi's sarcoma cases, and a competitor that walked away

Amlitelimab's Phase III package in atopic dermatitis was presented at the American Academy of Dermatology meeting, showing continuous improvement through week 24 with no plateau across COAST 1, COAST II and SHORE, and improvement to week 52 in the ATLANTIS Phase II extension. The safety discussion is where the risk sits: two cutaneous Kaposi's sarcoma cases have now been observed, one in ATLANTIS and one in the ESTUARY Phase III extension.

"Number two is that we've, as I said, about 4,500 patients in blind and unblinded studies demonstrated two cases of Kaposi's, both of which were cutaneous, both of which are improving. And then number three is across our other side effects and other issues, they're balanced across placebo and treatment arm."
— Houman Ashrafian, EVP and Head of R&D

Management also reported no change in physician or payer enthusiasm following the AAD presentation, and noted that rates of fever, chills and pyrexia are lower than for any other molecule in the OX40 pathway. Regulatory submission is anticipated in the second half of 2026.

Assessment: Two cases in 4,500 patients is a low absolute rate and the cutaneous presentation with recovery on discontinuation is the benign version. The difficulty is that a competitor observing the same signal in the same pathway reached the opposite conclusion and discontinued, which turns a numerical argument into a mechanistic one that a label discussion will have to resolve. Amlitelimab is the most important internal asset in the immunology pipeline and its risk profile now has a regulatory question attached to it that was not there a year ago.

7. Itepekimab: the decision that keeps not arriving

Itepekimab in COPD has become the pipeline's open wound. It does not appear in the company's own 2026 and 2027 newsflow table in either this quarter's release or last quarter's, where the only itepekimab entry is chronic rhinosinusitis with nasal polyps data in 2027. Two separate analysts pressed for a decision and got the same answer twice.

"Pete, to your question about itepekimab, there's no slight of hand on itepekimab. We have to get regulatory approval before -- and a regulatory opinion before we move forward. We have to align with our partner, Regeneron. I'd like to reassure everybody that it's high on our dashboard, Manuela and I on this side of the alliance are partnered, and we will come back to you as soon as we can."
— Houman Ashrafian, EVP and Head of R&D

Management added that a competitor's positive IL-33 Phase III results are one input among several being weighed, and that the eventual outcome will be a portfolio decision as much as a scientific one.

Assessment: "Portfolio decision" is the word management uses when a programme is being considered for termination. The competitive data cuts both ways: it de-risks the mechanism and simultaneously removes Sanofi's first-mover claim to it. Our working assumption is that itepekimab COPD does not proceed to a new Phase III, and we would treat a decision to proceed as the surprise.

8. lunsekimig and the respiratory pivot

The clearest good news in the quarter was lunsekimig, an anti-IL-13 and TSLP bispecific, which hit in two Phase II studies: AIRCULES in moderate-to-severe asthma, showing a statistically significant reduction in exacerbations regardless of biomarker status over 48 weeks plus improvement in pre-bronchodilator FEV1, and DUET in chronic rhinosinusitis with nasal polyps at 24 weeks.

"Just to be very specific, as you asked the specific asthma study, I'll make three points. Number one is we comfortably hit our primary endpoint, both statistically and clinically in all comers as anticipated. Number two, speaking to differentiation, as called out, on FEV1 and PROs, we were specifically differentiated."
— Houman Ashrafian, EVP and Head of R&D

On timing, management was unusually direct: the programme will not wait for the second Phase II readout before advancing.

"Number one is we do not anticipate waiting for the AIRLYMPUS results before we move forward. Number two is progression to Phase III will solely be subject to, obviously, internal portfolio decision-making, but currently a regulatory conversation."
— Houman Ashrafian, EVP and Head of R&D

Atopic dermatitis, where lunsekimig was also being studied, has been deprioritised in favour of respiratory.

Assessment: Two positive Phase IIs in codependent type 2 respiratory diseases, with a stated intent to move to Phase III without waiting, is the most constructive pipeline development in the quarter. The caveat management applied twice is real: these are relatively early studies and differentiation against established TSLP monotherapy has been asserted rather than demonstrated head to head. A 2026 Phase III start puts first data in the 2029 to 2030 window, which is just early enough to matter for the post-2031 gap.

9. Rare disease gets a pillar; Fabry gets a sentence

Venglustat met its primary endpoint in the LEAP2MONO Phase III in type 3 Gaucher's disease and received US breakthrough therapy designation. In the same paragraph of prepared remarks, the R&D head disclosed the failure.

"In Fabry's disease, the PERIDOT Phase III study did not meet its primary endpoint. The CARAT Phase III study is ongoing as we evaluate the path forward in Fabry's."
— Houman Ashrafian, EVP and Head of R&D

Not one analyst asked about it.

Assessment: The commercial asymmetry runs the other way from the disclosure asymmetry. Type 3 Gaucher's disease is a small neuronopathic subset of an already small population, while Fabry disease is the larger commercial opportunity and the one where Sanofi already has an installed base with Fabrazyme. Announcing a win and a loss in one breath and taking no questions on the loss is effective communication; it is not evidence that the loss is small.

10. Vaccines: buying adult immunisation while paediatric demographics erode

Heplisav-B arrived through the $2.2bn Dynavax acquisition that closed on 10 February and contributed €46m in the stub period, growing 18% on a market pro-forma basis. Against that, the paediatric franchise is being squeezed by falling birth rates, explicitly in China and in Rest of World generally, and Beyfortus fell 21.5% in the US against a prior-year inventory build and competition. The whole segment grew 2.1% at constant currency, an increment of roughly €27m, which is less than the Heplisav-B contribution alone.

Assessment: The strategy is coherent: adult immunisation has better demographics and better pricing than paediatric, and buying into it is the right response to a structurally shrinking birth cohort. The scale is the problem. A €46m quarterly asset does not offset a franchise whose largest volume markets are contracting, and the pipeline answer, a Phase 1/2 shingles candidate, is a decade from mattering.

11. Capital allocation: stated firepower of up to €15bn and a buyback almost finished

The CFO restated the balance-sheet capacity and made clear it flexes with what is bought.

"So on capital allocation, I said last time when we discussed our full year disclosure that we could invest up to EUR15 billion this year and retain our AA rating in BD and M&A. By the way, it depends on what we buy. Because if we buy commercialized asset, it would go probably even maybe potentially up to EUR10 billion more."
— François-Xavier Roger, Chief Financial Officer

Priorities were named as immunology, rare disease and vaccines, with white space not excluded. Meanwhile net debt rose from €11,008m at year-end to €12,900m, driven by the €1,660m Dynavax outflow and €806m of buyback, and the €1bn repurchase programme was €921m complete at the release date. Net financial expense was €78m against €68m, well below where the market had modelled it, and the CFO attributed that to deals not yet done.

Assessment: A company that has told the market it can deploy €15bn, has deployed €2.2bn on a €46m-a-quarter vaccine asset, and is running below its own financing-cost guidance because larger deals have slipped, is a company whose capital allocation is waiting for someone. The two in-licensing deals struck in the quarter, a JAK/ROCK inhibitor and a trispecific T-cell engager, are sensible Phase I and II shots on goal and cost little. Nothing here addresses 2031.

12. The handover

Paul Hudson's tenure as chief executive from 2019 to 2026 ended before this print. The interim chief executive opened the call by thanking his predecessor, and closed a question about what advice he would offer his successor with the most candid answer on the call.

"I would be very cautious in the advice that I would give her. But the first one is to take some time to make the right diagnostic. I think the company has considerably changed in the last 5 to 10 years."
— Olivier Charmeil, Interim CEO

Management was also asked directly whether business development had been paused pending the arrival of the new chief executive, and denied it.

"So we have not stopped working. We have not stopped being active in the market, including in BD. So as Olivier said, we have been very active."
— François-Xavier Roger, Chief Financial Officer

Assessment: The denial is credible on the evidence of two in-licensing deals and a completed acquisition in the quarter. But "take some time to make the right diagnostic" is an unusually clear statement that a strategy review is coming, offered by the person best placed to know. Every commitment made on this call, including the operating-income growth pledge for 2026 and 2027 and the shape of the Dupixent life-cycle plan, is made by an administration that will not be the one executing it. Investors are being asked to price a strategy that has not been announced.

Guidance & Outlook

Nothing in the top two rows moved after a quarter that grew 13.6% at constant currency, which by itself tells you what management expects from the balance of the year. The CFO was explicit about why.

"Please note that we have a tougher comparison base in H2 with Dupixent's new indication launches and the consolidation of Ayvakit, which started in July 2025."
— François-Xavier Roger, Chief Financial Officer

Implied quarter-over-quarter ramp. FY2025 sales were €43,626m. Q1 2026 grew 13.6% at constant currency on a Q1 2025 base of €9,895m, which is a constant-currency equivalent of about €11,241m against a nine-month comparative base of €33,731m. Growing the full year 7% at constant currency implies about 5.1% for the remaining three quarters; 8% implies about 6.4%; 9% implies about 7.6%. In other words, the guide as it stands assumes constant-currency growth roughly halves from here. Some of that is the Ayvakit and Heplisav-B consolidations annualising, some is the Dupixent gross-to-net base normalising, and some is genuine conservatism, but the deceleration is embedded in the reaffirmation whether management frames it that way or not.

Street at. The market entered the print with a reported-basis number in mind and got a beat on both published lines. Because the guide was untouched, published full-year estimates have limited room to move on this print except at the margin: the Q1 beat flows through, the Q2 to Q4 shape does not change, and the newly quantified €400m Regeneron headwind and c.€400m of divestment gains roughly offset inside operating income. Our expectation is that full-year business EPS estimates settle in a narrow band around €8.30, which is where a high-single-digit constant-currency sales guide, EPS growth slightly ahead of it and a 3% currency drag lands.

Guidance style. Sanofi guides to a growth descriptor rather than a numerical range, which removes the beat-and-raise mechanic entirely and makes the annual guide almost impossible to miss before the fourth quarter. The 2025 outturn is the relevant precedent: sales grew 9.9% at constant currency and business EPS grew 15.0%, so earnings ran five points ahead of the top line rather than slightly ahead of it. That history argues for treating the FY26 descriptor as a floor rather than a forecast. It also means the reaffirmation carries less information than a range would have, which is part of why the market discounted it.

Analyst Q&A Highlights

Why the loss-of-exclusivity slide appeared now

The most pointed question of the call was not about the quarter at all. It asked why a topic Sanofi had refused to discuss a year ago suddenly had its own slide, and offered four candidate explanations, three of them unflattering. Management split the answer across the General Counsel and the CFO, and the interim chief executive closed it by attributing the disclosure to a commitment made by the departing chief executive.

Q: "I am just curious why a year ago, Sanofi wouldn't speak to Dupixent LOE extension, but now includes slides in the deck. It seems that there are four possible reasons for this change. The first is that Sanofi now has more confidence, and I'm wondering why. Second, the outlook for the pipeline assets expected to form the next generation is unclear. Third, the LOE is near. Or fourth, a change in communication strategy may be related to the CEO change. In the absence of any other information, I think we have to assume it's the pipeline. I'm wondering if you would push back on that."
— Steve Scala, TD Cowen

A: "Yes. No, Steve, I think that, anyway, there is a logic that we talk about it because we get nearer to the LOE. And we see that there is a very strong appetite from the investor community to understand what's coming after the LOE of Dupixent. It's a major product for us. So I think we see that there is an interest, and we need to answer to the investor community."
— François-Xavier Roger, Chief Financial Officer

Assessment: Management chose the third of the four offered explanations, the neutral one, and explicitly rejected the fourth. The answer is plausible but it does not engage the substance of the challenge, which was that a company only starts talking about a cliff when it has run out of better things to talk about. Three separate executives contributed to the answer, which is itself a signal of how carefully the topic has been prepared.

The mechanics behind every-four-week dosing

A recurring line of questioning tried to convert the extension pillar from a concept into a specification: the technology, the partner, the economics, the completed work and the publication plan. One of five specifics was confirmed.

Q: "So just going back to the Q4 weekly Dupixent. Can you just confirm if it's hyaluronidase co-formulation, who the partner is and what commercial payways you might have on that? And what formulation studies have been completed to date? And if there's any public data or if you intend to share any public data on that?"
— Graham Parry, Citi

A: "Yes, I can confirm that it is hyaluronidase with a partner. We won't disclose any more than that at this stage. And then on the second question, we don't disclose the milestones for internal decisions around the IL-4 receptor alpha."
— Houman Ashrafian, EVP and Head of R&D

Assessment: The confirmation of hyaluronidase narrows the field of possible partners to a very short list and implies a royalty or milestone obligation that has not been sized. The refusal to discuss economics on a life-cycle programme intended to defend 40% of group revenue is a meaningful information gap, not a routine confidentiality position. Follow-up on whether the co-formulation generates its own intellectual property produced only a statement of intent to protect every innovation.

When the patent fight actually starts

A question about litigation timing drew the most revealing answer of the session, because it made explicit that the absence of challenges is a function of the calendar rather than of deterrence.

Q: "So first on the patent side, just hoping to get a little bit more clarity on how we should be thinking about the timing of potential resolution of the result. Typically, we see something like a major series of settlements two to three years before. Can you say that you're proactively working on that kind of an outcome to happen sooner rather than later? Or should we anticipate a standard extended process in the courts, particularly in the US?"
— Seamus Fernandez, Guggenheim Securities

A: "So if and if we wanted to give clarity to our investors of the strength and even if we have people lining up to discuss. There is nobody at the moment because nobody has challenged our patents. Typically, this happens closer for biologics. This happens closer to launch. We do intend to vigorously defend all these patents to the extent we feel at some point that people understand the strength of our case, and we want to give people clarity, we will do that, but we are quite away before that because we have not been challenged at this stage."
— Roy Papatheodorou, EVP and General Counsel

Assessment: This is the answer to hold on to. Management is telling the market that the information which would actually resolve the 2031 question, a challenge, a settlement, a court outcome, does not exist yet and will not exist for some time. Anyone underwriting Dupixent beyond 2031 today is underwriting an untested patent estate. That is not a criticism of the estate; it is a statement about what is knowable, and it is why a discount to the sector is rational rather than an anomaly.

The shape of earnings as the Regeneron reimbursement runs out

Of the two questions directed squarely at the profit and loss, the one on the earnings progression produced the quarter's most consequential new number, and it had to be asked twice before the horizon was clarified.

Q: "So François, can you discuss the quarterly EPS progression ahead, including the impact of the Dupixent alliance R&D reimbursement step down?"
— David Risinger, Leerink Partners

A: "So probably net around EUR400 million negative impact BOI this year and maybe EUR700 million next year negative again on the top of what we get this year."
— François-Xavier Roger, Chief Financial Officer

Assessment: Roughly €1.1bn of cumulative operating-income headwind over two years, disclosed in response to a question rather than in the prepared remarks, sitting alongside a reaffirmed commitment to grow operating income in both margin and absolute terms across the same two years. Those two statements are compatible only if the underlying business accelerates or costs come out. Management asserted the first and did not address the second.

Two safety cases and a competitor that reached the opposite conclusion

The sharpest challenge on the pipeline concerned amlitelimab, and it was framed as a direct comparison with a rival that discontinued its own OX40-pathway programme on what the questioner characterised as the same observation.

Q: "Kirin observed exactly the same, but said that sarcoma being mechanistic was a reason to kill the program. Why is you right and Kirin wrong?"
— Matthew Weston, UBS

A: "Yes. Matthew, thank you for your question. I'm not -- I wouldn't speculate on the decision-making within Kyowa Kirin and Amgen. From our own perspective, all I can tell you is that the benefit risk of amlitelimab is differentiated. We are consistently with the opinion that we bring that to patients."
— Houman Ashrafian, EVP and Head of R&D

Assessment: Declining to speculate on a competitor's reasoning is the correct posture and also a non-answer to the mechanistic question underneath it. The follow-on detail was better than the headline response: two cutaneous cases across approximately 4,500 blinded and unblinded patients, both recovering on discontinuation, with overall malignancy rates similar to placebo. That is a defensible dataset. Whether it is a defensible label is a question for a regulator in the second half of 2026, not for this call.

Itepekimab and the decision that keeps slipping

A recurring line of questioning returned to the COPD programme a second time within the hour, this time explicitly noting that a study analysts had expected to be enrolling had not started, and asking whether a competitor's data had changed the commercial calculus.

Q: "I'm sorry to labor the point, but going back to the itepekimab question. What are the exact go-forward plans? Because it seems to be dragging somewhat. I think we all thought that AERIFY would have begun quite a number of months ago. So can you just clarify when, in fact, AERIFY might begin in recruitment? Or does the developments across the pond or across the channel at Astra sort of change your thinking about the commercial potential here?"
— Peter Verdult, BNP Paribas Exane

A: "Pete, to your question about itepekimab, there's no slight of hand on itepekimab. We have to get regulatory approval before -- and a regulatory opinion before we move forward. We have to align with our partner, Regeneron. I'd like to reassure everybody that it's high on our dashboard, Manuela and I on this side of the alliance are partnered, and we will come back to you as soon as we can."
— Houman Ashrafian, EVP and Head of R&D

Assessment: The phrase "no slight of hand" is a response to an accusation nobody made, which is usually a tell. No date was given, no start condition was specified beyond a pending regulatory opinion, and the programme remains absent from the company's own two-year newsflow table. Treating this asset as terminated until told otherwise is the conservative and, we think, correct modelling position.

Whether capital deployment is on hold until the new chief executive arrives

The question that most directly addressed the governance overhang came in writing rather than on the line, and management answered it without hedging.

Q: "And then the second one is for François, is BD on pause until Belén arrives? Or is capital deployment in flight or on an ongoing strategy?"
— Michael Leuchten, Jefferies (submitted in writing)

A: "No. But I mean, obviously, we are looking forward to welcoming Belén in a few days, but business goes on in the meantime. So we have not stopped working. We have not stopped being active in the market, including in BD. So as Olivier said, we have been very active."
— François-Xavier Roger, Chief Financial Officer

Assessment: The evidence supports the denial for small transactions: two in-licensing deals were signed in the quarter and the Dynavax acquisition closed in February. It does not support it for large ones. The same executive attributed the quarter's below-plan financing cost to larger transactions arriving later in the year than budgeted, which is the definition of deals not happening on the original schedule. Both statements can be true, and together they describe a company doing maintenance business development while the strategic decisions wait.

What They're NOT Saying

1. No operating-margin guidance for 2026. Sanofi guides sales growth and EPS growth and nothing in between, which is convenient in a year when the profit-share line and the reimbursement step-down are both compressing the middle of the P&L. The commitment to grow operating income in margin and absolute terms was made in Q&A, not in the guidance framework, and carries no number.
2. No quantified erosion scenario for Dupixent after March 2031. Three pillars were presented and none was sized. There is no disclosed base case for how much of a franchise that sold €15,714m in 2025 survives the first year of biosimilar entry, no disclosed sensitivity, and no disclosed range. For the single asset representing 39.7% of sales, that is the largest information gap in the equity story.
3. The every-four-weeks co-formulation partner, economics and data plan. Confirmed as hyaluronidase; everything else was declined. Clinical studies are expected to start in the second half of 2026, which means no human data before 2027 on a defence intended to matter by 2031.
4. Any threshold for the IL-4 receptor alpha decision. Asked directly what data points and what bar would trigger full alliance investment, management said it does not disclose milestones for internal decisions. The asset sits in the "innovate" column of the 2031 slide, so the market is being shown a pillar without being told what would make it load-bearing.
5. Any commentary on US drug pricing, tariffs or the agreement struck with the US government. The word tariff does not appear in the call. Neither does most-favoured-nation pricing, Medicare, or the agreement with the US administration to lower medicine costs that Sanofi itself highlighted in its January release. With the United States at 50.3% of sales and 51.0% of currency exposure, an entire earnings call passing without the topic being raised by management or by a single analyst is conspicuous.
6. Any discussion of the Fabry failure. PERIDOT missing its primary endpoint was disclosed in one sentence alongside a Gaucher's disease win and drew zero questions. The path forward was described as under evaluation.
7. Opella. Sanofi retains a 48.2% interest in the consumer health business it sold, and its share of losses runs through the IFRS accounts. Summary financials were deferred to the half-year, so a stake of that size went another quarter without disclosure.
8. What the incoming chief executive intends to do. Unavoidable, and management said as much. But it means the strategy underpinning every forward statement on this call, including the 2026 and 2027 operating-income commitment, is provisional.

Market Reaction

• Pre-print setup: The ADS closed at $46.90 on 22 April, down 3.2% year to date against an S&P 500 up 4.3%, down 11.5% over twelve months, but up 3.9% over the trailing thirty days, inside a 52-week closing range of $43.60 to $55.44. The Paris line closed at €80.78, down 2.3% year to date and 13.4% over twelve months, but up 6.6% over the prior thirty sessions from a €75.81 low, inside a 52-week closing range of €75.81 to €97.92. The stock went into the print off its lows, out of favour for a year, and cheap.
• Reaction session, 23 April: Both lines gapped hard and faded. Paris opened at €83.05, traded as high as €84.04, and closed at €81.76, up 1.21% on 3.26m shares against a 30-day average of 2.62m, or 1.24 times normal. The ADS opened at $48.51, a 3.4% gap, ranged $47.34 to $48.60, and closed at $47.53, up 1.3% on 5.4m shares against a 3.1m average, or 1.7 times normal. The S&P 500 fell 0.4% and the CAC 40 fell 0.2% on the same session.
• Next-day session, 24 April: The ADS closed at $46.78, down 1.58%, while the S&P 500 rose 0.80%. Paris closed at €80.08, down 2.05%, against a CAC 40 up 0.30%. Net across the two sessions the ADS moved from $46.90 to $46.78, a decline of 0.26%, against an S&P 500 up 0.38%.

The price action is the cleanest read on the quarter available. A beat on both published lines, double-digit constant-currency growth on the top and bottom lines, reaffirmed guidance and a positive Phase III readout produced a gap of more than three points that was two-thirds surrendered by the close and entirely surrendered by the following afternoon. Both listings finished below their pre-print levels within twenty-four hours of the call ending, and they did so while their respective indices rose.

That pattern is not a verdict on the numbers. It is a verdict on the call. The opening print rewarded the release, which is a genuinely good document: 13.6% growth, a launch portfolio up 49.6%, five approvals. The fade began during and after the hour in which management declined to date the co-formulation, declined to size the patent estate, declined to commit on itepekimab, and quantified an €1.1bn two-year operating-income headwind that had not previously been in the public domain. The market took the beat, listened to the Q&A, and gave the beat back.

The second element is positioning. A stock down 11.5% over twelve months but up 3.9% in the preceding month had already begun to be bought ahead of the print. That is the classic setup for a sell-the-news fade: the good news was partly in the price, and the incremental buyer needed a reason to underwrite 2031, which the call did not supply.

Street Perspective

Debate: Is the Dupixent patent estate worth anything beyond March 2031?

Bull view: The bull case on the Street is that a biologic with more than fifty issued US patents, formulation and method-of-treatment coverage running to 2045, no filed challenges and a manufacturing barrier typical of monoclonal antibodies will erode far more slowly than a small molecule, and that the market is applying a small-molecule cliff to a biologic asset. On this view every year of delayed or partial erosion is worth several euros of value that the current multiple does not capture.

Bear view: The bear camp contends that the compound patent is the only one that has never lost, that method-of-treatment and formulation claims are the weakest links in every biologic defence, that biosimilar developers have had a decade to design around, and that the company's own decision to start talking about the cliff five years out signals concern rather than confidence. On this reading the terminal value of roughly 40% of revenue is genuinely uncertain and the discount is correct.

Our take: The bear framing has the better of the argument today, not because the estate is weak but because nothing about it is testable yet. Management said as much: no one has challenged the patents and, for biologics, challenges arrive close to launch. Until a filer appears, the bull case rests on an assertion and the bear case rests on a base rate, and base rates win in the absence of evidence. This should resolve, in either direction, well before 2031, and the resolution is the single largest re-rating catalyst in the name.

Debate: Which growth rate describes this business, 13.6% or 6.2%?

Bull view: Some desks argue that constant currency is the only honest measure of operating performance, that translation effects mean-revert, and that a business compounding sales in the low teens with EPS ahead of it is materially mispriced at under ten times earnings. On this view the reported line is noise imposed by a reporting-currency accident.

Bear view: The bear camp points out that a euro-reporting company with half its revenue in dollars has a structural, recurring translation exposure that is not a one-off; that the company's own guidance embeds a 2% sales and 3% EPS currency drag for the full year; and that the dividend, the buyback and the reported earnings that fund both are paid in the weaker measure, not the stronger one.

Our take: Reported growth is what shareholders receive and it is the number we model. The useful synthesis is that constant currency tells you whether management is executing, which they are, while reported tells you what the execution is worth this year, which is less. Both matter, but only one pays the dividend, and the guidance itself is set on a constant-currency basis with the currency drag disclosed separately, which is an implicit acknowledgement of exactly this distinction.

Debate: Is sub-ten-times earnings with a 5% yield an opportunity or a correctly priced terminal risk?

Bull view: A growing consensus view among value-oriented holders is that roughly ten times forward business earnings, a five percent gross dividend yield backed by thirty-one consecutive years of increases, a AA-rated balance sheet with stated capacity of up to €15bn and a business growing at double digits operationally is a rare combination in large-cap pharmaceuticals, and that the market is over-discounting an event five years away.

Bear view: The skeptics counter that the multiple has been in this range for a reason, that the cheapness is a function of a 2031 hole nobody has filled, that the pipeline has produced two high-profile failures in six months against one small win, and that a company changing chief executive mid-transition is not the moment to underwrite a strategy.

Our take: Both sides are describing the same fact and disagreeing about whether it is priced. We think it is roughly priced. Ten times earnings with a five percent yield offers a defensible total return without requiring the 2031 question to be answered favourably, which makes the downside manageable, but the multiple will not expand until either the patent position is tested or the pipeline produces a franchise-scale asset. That combination, limited downside and a gated re-rating, is the definition of a Hold rather than either an Outperform or an Underperform.

Model Update & Valuation Framework

Valuation. On our c.€8.30 FY26 business EPS estimate, the Paris line at its 23 April close of €81.76 trades on 9.8 times, and on the FY2025 actual of €7.83 it trades on 10.4 times trailing. The proposed 2025 dividend of €4.12, subject to approval at the 29 April annual meeting, is a 5.0% gross yield on the same close. Because one ADS represents half an ordinary share, the ADS line carries the same multiples: at the 23 April close of $47.53 the shares trade at approximately 9.8 times our FY26 estimate.

Fair value framework. We set a twelve-month fair value range of $48 to $54 per ADS, equivalent to 10 to 11 times our FY26 business EPS estimate. The midpoint of roughly $51 implies about +7% from the 23 April close of $47.53, to which a gross dividend yield of roughly 5% can be added. That is a market-like total return, which is the arithmetic behind a Hold. The lower bound assumes no multiple expansion at all; the upper bound assumes the market pays an eleven multiple for a business executing at low-double-digit constant-currency growth, which we would regard as the ceiling until the 2031 question moves.

What would change the framework. Upward: a dated, partnered co-formulation programme with disclosed economics and a filing timeline; a favourable early resolution or settlement on the Dupixent estate; lunsekimig entering Phase III in COPD with a differentiated label ambition; or a franchise-scale acquisition funded within the AA constraint. Downward: an itepekimab COPD termination confirmed; an amlitelimab label restriction arising from the Kaposi's sarcoma cases; a further step-up in the Regeneron profit-share rate; or a strategy reset from the incoming chief executive that resets the 2026 and 2027 operating-income commitment.

Thesis Scorecard Post-Earnings

This is our first published note on Sanofi, so the scorecard establishes the pillars rather than grading a standing thesis. Each is stated in the form we will carry and mark in subsequent quarters.

Overall: Thesis established. The operating business is performing better than the reported numbers suggest and the reported numbers are what shareholders receive; both statements are load-bearing. Three of four bear points were confirmed in their first quarter under observation, and the one that was not is the one that resolves itself in May.

Action: Hold. We would become buyers on evidence that the launch cohort is compounding above 25% organically, on a dated and economically disclosed Dupixent extension programme, or on a share price that discounts the 2031 risk more completely than nine to ten times earnings does. We would become sellers on an amlitelimab label problem, a Regeneron renegotiation on worse terms, or a strategy reset that abandons the 2026 and 2027 operating-income commitment.