Sanofi pauses phase 2 bronchiectasis trial of SAR445399 for strategic reasons

Sanofi has halted a phase 2 study of its monoclonal antibody SAR445399 in adults with non‑cystic fibrosis bronchiectasis. The trial, which began in April, was a randomized, double‑blind, placebo‑controlled study aimed at measuring changes in mucus plug scores.

The company announced the pause on July 29, the day before its second‑quarter earnings call. Sanofi said the decision was driven by a company‑wide portfolio review for strategic business reasons, not by any safety concerns.

The suspension comes amid a turbulent period for Sanofi, which recently replaced its CEO and has been reassessing its R&D pipeline. In the past few months the firm has discontinued several other assets, including amlitelimab for atopic dermatitis and two additional candidates, following disappointing trial outcomes.

Analysts view the move as part of a broader effort to streamline the pipeline and focus resources on more promising programs, though the halt underscores ongoing challenges in the company’s lung‑disease portfolio.