Raising the Bar: European General Court Sets Steep Standard for Challenging Technically Complex Regulatory Decisions

In its detailed judgment of 23 September 2026 in Case T-455/24, the EU General Court firmly established the demanding threshold for overturning regulatory decisions rooted in scientific and technical evaluation. 

The case concerned the revocation of a conditional marketing authorisation—which under EU pharmaceutical law must be renewed annually—for a medicinal product used in treating a rare condition, following a key clinical trial’s failure to demonstrate efficacy. The authorisation, initially granted based on a dataset that was not considered ‘comprehensive’ and subject to confirmatory study requirements, was withdrawn after both the Committee for Medicinal Products for Human Use (CHMP) and an ad hoc expert group concluded that the product’s efficacy was unproven and its risk-benefit balance unfavourable.

The applicant’s challenge centred on alleged conflicts of interest among experts, procedural missteps, the timing of the revocation during a pending renewal, and the scientific basis for the decision. The Court found no evidence of current, product-specific conflicts of interest that could undermine impartiality; past or general interests were not enough. Minor procedural irregularities, such as administrative issues with declarations of interest or the manner of expert assessment, were deemed immaterial to the fairness or outcome of the process.

On the merits, the Court emphasised that judicial review of decisions based on technically complex assessments is highly deferential. It will not substitute its own scientific judgment for that of the European Medicines Agency (EMA) or European Commission, intervening only in cases of manifest error, illogical reasoning, or serious procedural breach. Central to the Court’s reasoning was the hierarchy of evidence: the negative result of a robust, randomised controlled trial outweighed real-world data and post-hoc analyses, which could not, by their volume or nature, overcome the controlled trial’s findings.

The precautionary principle featured prominently, allowing regulators to act on “serious and conclusive evidence” that raises reasonable doubt about efficacy or the benefit-risk balance, without requiring absolute certainty of harm. The Court also addressed proportionality, holding that revocation was not a disproportionate response when efficacy could not be established—less restrictive measures, such as imposing new obligations, would not achieve the objective of protecting public health. As for legitimate expectations, the Court found no violation: prior regulatory communications had expressly reserved the right to reassess the data, and no assurance had been given that authorisation would continue in the face of negative evidence.

The takeaway is clear: legal challenges to regulatory decisions based on technical assessments face a high bar. Without clear, material error or genuine bias, courts will defer to the regulator’s scientific expertise, the established hierarchy of evidence—where randomised controlled trials are decisive—and the imperative to act proportionately and in the public interest, especially where patient safety is at stake.

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