Pfizer Inc. (NYSE:PFE) and Valneva SE (NASDAQ:VALN) have pushed their Lyme disease vaccine candidate into the final stretch of European approval, with the European Medicines Agency starting its official review of the application. The move comes with a caveat: one of the two primary endpoints in the trial failed to meet its statistical threshold.
The companies announced on August 14 that the EMA had validated the Marketing Authorization Application for PF-07307405. That validation means the agency has accepted the submission and will now move forward with a formal assessment of whether the vaccine can be sold in Europe.
The Trial Behind the Submission
The application rests on the Phase 3 VALOR trial, a study of 9,437 participants aged five and older from high-incidence Lyme disease locations in the US, Canada, and Europe. The design called for four doses on a phased schedule: one at months 0, 2, and 5-9, followed by a fourth dosage around a year later, shortly before the start of the next Lyme season.
Topline data released in March 2026 showed the vaccine reduced confirmed Lyme disease cases by over 70%. The vaccine was generally tolerated, with no safety issues detected. But the statistical picture was less clean than the headline number suggests.
The trial had two prespecified analyses, each serving as a primary endpoint. The first analysis showed 73.2% efficacy but failed the trial’s predefined statistical criterion. The lower bound of the 95% confidence interval was 15.8%, below the required 20%. The second analysis showed 74.8% efficacy and did meet that threshold.
The Statistical Hiccup
The difference between the two numbers matters. A vaccine can hit its efficacy target in the middle of a confidence interval and still fail a regulatory test if the lower bound falls short of the threshold. That is exactly what happened here.
Pfizer and Valneva have not publicly commented on why the first analysis failed the statistical test. The companies have presented the overall efficacy data as supportive of the application, but the EMA review will need to grapple with the discrepancy between the two primary endpoints.
| Analysis | Efficacy | Confidence Interval Lower Bound | Result |
|---|---|---|---|
| First prespecified | 73.2% | 15.8% | Failed threshold |
| Second prespecified | 74.8% | Not specified | Met threshold |
The EMA will need to decide whether the overall data justify moving forward, even though one of the two primary endpoints did not clear the bar.
Valneva’s Stake in the Outcome
Valneva SE (NASDAQ:VALN) is the smaller partner in the 2020 collaboration deal that brought the vaccine into existence. The company views the candidate as a clean competitive setup, a rare spot in the vaccine industry where new entrants often face competition from existing treatments.
Under the terms of the partnership and license agreement, Pfizer Inc. (NYSE:PFE) will hold exclusive rights to produce and commercialize the vaccine if it is approved. Valneva SE (NASDAQ:VALN) will benefit as a development partner.
The stakes for Valneva are significant. A successful EMA review could position the company as the leading developer of a Lyme disease vaccine, a distinction it has framed for itself. The outcome will also determine whether the smaller partner secures a share of a potential commercial launch.
Institutional Support Between the Partners
The institutional support picture differs sharply between the two companies. Pfizer Inc. (NYSE:PFE) remains a strong name in the institutional space, with hedge fund ownership stable at 83 funds in the second quarter of 2026, the same as the first quarter. That reflects its position as a large, diversified pharmaceutical holding, rather than a name driven by a specific pipeline event.
Valneva SE (NASDAQ:VALN) has little hedge fund exposure. Only 4 funds held a position in the second quarter, up from 1 in the first quarter.
What the EMA Review Decides
The EMA review will determine whether PF-07307405 clears the final hurdle before reaching European markets. The agency will consider the totality of the data, including the two primary endpoint results and the safety profile.
The companies have not said when they expect a decision from the EMA. But the path from validation to approval is rarely quick, and the statistical hiccup in the trial data adds uncertainty to what was already a competitive landscape.
Our View on the Data
The vaccine candidate met its primary endpoint’s efficacy number but failed the statistical test because the lower bound of its confidence interval fell short. That is a messy situation for any drugmaker, and it is murkier here than the headline numbers suggest.
The EMA will need to decide whether the overall efficacy data justify moving forward, even though one primary endpoint did not clear the bar. If the agency accepts the application, it will be a vote of confidence in the vaccine’s potential.
The vaccine’s future depends on the EMA’s reading of the data. For now, the companies have cleared the submission hurdle and are waiting on the agency’s verdict.
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