The licence and supporting evidence for omalizumab biosimilar

Scope

Two omalizumab biosimilars will be available to the NHS: Omlyclo (Celltrion) and Adcomfo (Advanz). We provide information relating to indications, formulations, evidence and differences between biosimilars at the point of licensing onwards.

Licensed indications

Omalizumab biosimilars are licensed for the same indications as the reference product Xolair (Novartis):

• allergic asthma
• chronic rhinosinusitis with nasal polyps (CRSwNP)
• chronic spontaneous urticaria (CSU)

Refer to the individual summary of medicinal product characteristics (SmPC) for further information.

Note: the 75mg strength preparations (all Omalizumab products) are not licensed for chronic spontaneous urticaria (CSU). 

Licensed preparations

Different presentations are available:

Xolair

• Available in 75mg, 150mg, and 300mg strengths
• Both pre‑filled syringes (PFS) and pre‑filled pens (PFP)

Omlyclo

• Available in 75 mg and 150 mg strengths
• Both pre‑filled syringes (PFS) and pre‑filled pens (PFP)

A 300mg strength PFS is expected to launch later in 2026. There are plans for a 300mg PFP to follow.

Adcomfo

• Will be available in 75 mg and 150 mg strengths.
• Initially as pre-filled syringes (PFS) only.

PFP versions are expected later in 2026. A 300mg strength PFS and PFP may launch in 2027. 

Evidence supporting safety and efficacy

The clinical efficacy, safety profile and immunogenicity of omalizumab biosimilars and the reference product (Xolair) are similar.

Clinical trial population

Omlyclo is considered highly similar to the reference product (Xolair) based on results of the clinical trial in patients with chronic spontaneous urticaria (CSU). Its licence is extrapolated to the additional indications already approved (licensed) for the reference product (Xolair). Thus, avoiding unnecessary repetition of clinical trials.

The CSU population was chosen for the biosimilar efficacy study in preference to that with allergic asthma. Patients with CSU were considered a more homogenous population and therefore more sensitive to any potential differences between products.

See understanding biological and biosimilar medicines (SPS page) for further information regarding the regulatory process for biosimilar medicines.

Omlyclo

We have summarised the efficacy and pharmacokinetic data for Omlyclo.

Efficacy

A published randomised, double-blind, active controlled parallel group study compared Omlyclo (biosimilar omalizumab, CT-P39) to the reference product (Xolair). The study enrolled 409 patients aged between 12 and 75 years with CSU not responding to antihistamine treatment. It showed similar clinical efficacy after 12 weeks of treatment. The weekly itch severity score (ISS7) reduced by an average of 9.21 points with Omlyclo compared with an average of 9.98 with Xolair [95% CI, -0.37, 1.90]. These results were within the predefined equivalence margin of [-2.0, 2.0].

Pharmacokinetic trial data

In a published randomised, double-blind, two-part, single-dose, pharmacokinetic study 146 healthy adults received 150mg Omlyclo or Xolair. The study demonstrated primary outcomes of pharmacokinetic parameters within pre-specified equivalence margins. Safety and immunogenicity were comparable between products.

For further details, see the European Public Assessment Report.

Adcomfo

Efficacy

A published abstract randomised, double‑blind, active‑controlled study compared Adcomfo (biosimilar omalizumab ADL‑018) to the reference product (Xolair). The study enrolled 600 adult participants with CSU unresponsive to antihistamines. It showed similar clinical efficacy after 12 weeks of treatment. The weekly itch severity score (ISS7) reduced by an average of 10.00 points with Adcomfo compared with an average of 9.82 points with Xolair [95% CI, -0.619, 0.257]. These results were within the predefined equivalence margin of [-2.5, 2.0].

Pharmacokinetic trial data

In a randomised, double-blind, three-arm, single-dose, pharmacokinetic study, 306 healthy adults received 150mg Adcomfo (ADL-018) or Xolair (EU-approved or US-approved). The study results have not yet been published, but the primary pharmacokinetic outcomes were evaluated against pre-specified bioequivalence margins to demonstrate pharmacokinetic similarity.

Differences between brands

Comparison of pharmaceutical aspects between omalizumab biosimilar (Omlyclo) and the reference product (Xolair).

Administration

The first three doses of omalizumab must be administered by or under the supervision of a healthcare professional. For those with no known history of anaphylaxis, patients or caregivers can administer omalizumab (Xolair, or biosimilars) from the fourth dose onwards. Appropriate training should be provided.

Switching between brands

The requirement to give the first three doses under supervision is molecule-specific, not brand specific. Providing appropriate training on the new device has been provided:

• those stable self-administering Xolair can switch to self-administration of a biosimilar
• those stable receiving carer-administered Xolair can switch to carer-administration of a biosimilar

The administration instructions for Omlyclo and Adcomfo are consistent with those for the equivalent Xolair device. However, device and packaging colouring differs between brands and strengths and may require additional attention during selection and administration. Full details are provided in the patient information leaflets.

Packaging and associated risks

To minimise errors, consider processes to avoid inadvertent switching between omalizumab originator and biosimilar.

Be aware of differences in packaging colour that could cause confusion.

• Xolair and Adcomfo use blue to identify the 75mg doses
• Omlyclo uses blue to identify the 150mg dose

Ensure there are processes in place to avoid mis-selection, especially if there is a period when multiple brands are available.

Excipients

Omlyclo and Xolair contain the same excipients, but Adcomfo uses different excipients. These differences are unlikely to be clinically meaningful.

Adcomfo uses poloxamer 188 as its surfactant. Xolair and Omlyclo use polysorbate 20.

Adcomfo uses a phosphate-based buffer system (sodium phosphate dibasic, heptahydrate and sodium phosphate monobasic, monohydrate). Xolair and Omlyclo use a histidine-based buffer.

Note: The Omlyclo SmPC expresses the L-isomer forms of several excipients, for example L-histidine. L-histidine is a synonym for histidine; the terms can be used interchangeably.

Presence of latex

Differences exist between omalizumab products.

Xolair pre-filled syringes

The removable needle cap may contain dry rubber (latex) and should not be handled by anyone who is sensitive to latex. Use in latex-sensitive individuals has not been studied, therefore risk of a hypersensitivity reaction cannot be ruled out.

Xolair pre-filled pens

No components contain natural rubber latex (confirmed by Novartis).

Biosimilars

Omlyclo (pre-filled syringes and pens) and Adcomfo (pre-filled syringes) are manufactured without the use of materials derived from natural rubber latex or dry natural rubber.

Storage and stability

Comparisons of storage and in use stability between omalizumab biosimilars and the reference product (Xolair):

Omlyclo

Store in a refrigerator (2 °C to 8 °C). 

The product may be kept for a total of 7 days at room temperature (25 °C) 

Xolair and Adcomfo

Store in a refrigerator (2 °C to 8 °C). 

The product may be kept for a total of 48 hours at room temperature (25 °C) 

Further resources

SPS have further resources on biosimilars and biosimilar omalizumab. 

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