(Reuters) -Britain's medicines regulator said on Tuesday that any new or worsening reactions in patients' eyes arising from use of Sanofi (EPA:SASY)'s best-selling asthma and eczema drug Dupixent should be promptly reviewed by healthcare professionals.
The UK's Medicines and Healthcare products Regulatory Agency said most ocular reactions seen with the drug are mild and can be managed.
European and U.S. health regulators have listed conjunctivitis, an eye irritation that can cause redness and discomfort, as a side effect of Dupixent.
The eczema and asthma drug generated 2021 sales of 5.25 billion euros ($5.43 billion), accounting for 13.9% of group revenues and making it Sanofi's biggest-selling product.
The French drugmaker expects the treatment to generate up to 13 billion euros in sales in its best year as it seeks to widen its use across a number of inflammatory conditions.
Sanofi did not have an immediate comment.
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