New drug substitution rules in France

A new decree, published in the Official Journal on October 27, 2026, establishes the fourteenth interchangeable biological similar group in France. This group includes the reference drug Xolair, made by Novartis, and its biosimilar Omlyclo, produced by Celltrion Healthcare. Pharmacists can now substitute one for the other, even for patients already receiving treatment, without requiring a new prescription specifically for the biosimilar.

Omlyclo's approval and availability

Omlyclo is the first biosimilar of omalizumab to be authorized in the European Union. It received marketing approval on May 16, 2024, and began being sold in France in mid-September 2025. It is available in pen or pre-filled syringe form with dosages of 75 mg and 150 mg. The 300 mg dosage became available in France in May 2026.

General substitution procedures

The decree outlines standard procedures for all interchangeable drug groups. The prescribing doctor must inform the patient about the possibility of substitution. When a pharmacist performs the substitution, they must inform the patient, note the actual drug on the prescription, notify the prescriber, and record the product name and batch number. They must also ensure that the same drug is used in future prescriptions to maintain treatment continuity.

Special rules for omalizumab

For omalizumab, specific rules apply. Doctors may specify the type of administration device to use on the prescription. Pharmacists must help patients learn how to use any new device if needed. They must also inform patients about potential color differences in the caps of the administration devices, which can vary between different versions of the same drug dosage. Patients may switch back to their original drug based on their feedback.

Indications for Omlyclo

Omlyclo is approved for use in several conditions, including severe persistent allergic asthma in adults, adolescents, and children aged 6 to under 12 years. It is also used for severe adult nasal sinus polyps when added to intranasal corticosteroids, and for chronic spontaneous urticaria in patients aged 12 and older who are not adequately controlled by antihistamines.