The United Kingdom’s pharmaceutical self-regulatory body has determined that Sanofi breached established industry codes of practice with certain public statements made about its respiratory syncytial virus prophylactic therapy, following a complaint by Pfizer.

The Prescription Medicines Code of Practice Authority (PMCPA) said Sanofi’s comments, published in a newspaper interview, included claims that its Beyfortus product was more effective than Pfizer’s Abrysvo vaccine without direct comparative evidence, and thus violated rules governing the promotion of prescription-only medicines to the public.

The ruling stems from remarks made by Sanofi’s chief executive in an October 2024 interview, in which he suggested that, for clinical benefit, Beyfortus would be the preferred choice.

Pfizer challenged the characterisation of the remarks, asserting that the article effectively promoted Beyfortus with unbalanced and misleading assertions and disparaged its own RSV vaccine.

PMCPA’s panel concluded that no head-to-head comparative data existed to substantiate claims of superior effectiveness, and that the interview breached multiple provisions of the code, including those prohibiting misleading content and unbalanced information.

In its response to the ruling, Sanofi acknowledged the PMCPA decision and said it accepted the findings, reiterating its commitment to high standards of ethical conduct and responsible engagement with the public.

The regulator also noted that an attempt was made to remove the specific claim from the published article, but that it remained in the public domain without supporting evidence.

This episode highlights the strict regulatory environment governing pharmaceutical communication in the UK and underscores the importance of adherence to codes designed to protect public trust and ensure accurate information about prescription medicines.