Anti-TSLP (Thymic Stromal Lymphopoietin) Monoclonal Antibody Pregnancy: No available data on use in pregnant women to evaluate drug-associated risk of major birth defects, miscarriage or other adverse maternal or fetal outcomes. Placental transfer of monoclonal antibodies is greater during the third trimester, so potential fetal effects are likely to be greater then. In an enhanced pre- and post-natal development study in cynomolgus monkeys, placental transport was observed but there was no evidence of fetal harm at maternal exposures up to 168 times the exposure at the maximum recommended human dose of 210 mg subcutaneously.

Tezepelumab (CRSwNP / Severe Asthma)

Brand names: Tezspire

Tezepelumab is a subcutaneously administered monoclonal antibody used as add-on therapy in severe asthma and, increasingly, in chronic rhinosinusitis with nasal polyps (CRSwNP), under specialist supervision.

Auto-extracted from the source labelling — not yet independently clinician-verified. These values were distilled from the UK SPC (or the US label where noted) but have not had a clinician sign-off. Confirm against the current SmPC before prescribing.

Adult dose

Dose: 210 mg

Route: Subcutaneous injection into the thigh or abdomen (except the 2 inches / 5 cm around the navel); the upper arm may also be used if a healthcare provider or caregiver administers the injection — a patient should not self-inject in the upper arm. Rotate the injection site with each injection.

Frequency: Once every 4 weeks

US label dosage is a single 210 mg dose (one vial, one pre-filled syringe or one pre-filled pen) every 4 weeks for add-on maintenance treatment of severe asthma and of inadequately controlled chronic rhinosinusitis with nasal polyps (CRSwNP). Missed dose: administer as soon as possible, then resume the usual day of administration; if the next dose is already due, administer as planned. Preparation: remove from the refrigerator and allow to reach room temperature (generally 60 minutes); do not shake, do not expose to heat, do not return to the refrigerator once at room temperature; inspect visually — do not use if cloudy, discoloured, or containing large particles. Vials and pre-filled syringes are for administration by a healthcare provider; the pre-filled pen may be given by patients/caregivers after proper training. Do NOT discontinue systemic or inhaled corticosteroids abruptly on starting tezepelumab — decrease gradually if appropriate. Treat pre-existing helminth infections before therapy. Avoid live attenuated vaccines. Paediatric: safety and effectiveness are established in patients aged 12 years and older for BOTH severe asthma and CRSwNP, at the same 210 mg every-4-weeks subcutaneous dose (no per-kg dosing is given); not established below 12 years for asthma. Verify any paediatric use against a children's formulary. Geriatric: no overall differences in safety or effectiveness observed in patients 65 years and older. Available as 210 mg/1.91 mL (110 mg/mL) single-dose vial, pre-filled syringe and pre-filled pen. SOURCE CAVEAT: no UK SPC was retrieved — this is the US TEZSPIRE prescribing information (Amgen, label date 2025-10-17); UK indications, licensed age range and wording may differ, so confirm against the UK SPC. Source: openFDA/DailyMed label for TEZSPIRE (tezepelumab-ekko).

Dose auto-extracted from US FDA prescribing information (openFDA / DailyMed) — cross-check; US labelling may differ from UK — not yet clinician-verified. Always confirm against the product SmPC and your local formulary before prescribing.

Contraindications

Known hypersensitivity to tezepelumab-ekko or to any of its excipients

Side effects

Asthma (incidence ≥ 3%): pharyngitis
Asthma: arthralgia and back pain
CRSwNP (incidence ≥ 3%): nasopharyngitis, upper respiratory tract infection
CRSwNP: epistaxis, pharyngitis, influenza
CRSwNP: injection site reaction, back pain and arthralgia; hypersensitivity reactions (e.g. rash, allergic conjunctivitis) were observed in clinical trials and postmarketing cases of anaphylaxis have been reported — these can occur within hours but sometimes with delayed onset (days)

Interactions

No formal drug interaction studies have been performed with TEZSPIRE
Avoid use of live attenuated vaccines (§5.5 Warnings and Precautions)

Clinical monograph

How it works

It is a human monoclonal antibody that binds thymic stromal lymphopoietin (TSLP), an epithelial cytokine upstream of multiple inflammatory pathways, thereby blocking a key initiator of airway and sinonasal type-2 and non-type-2 inflammation.

Prescribing in practice

It is a biologic for specialist initiation only and must not be used to treat acute asthma exacerbations, acute bronchospasm or status asthmaticus.
Hypersensitivity reactions can occur, so administer with appropriate observation and counsel patients on recognising delayed reactions.
Live vaccines should generally be avoided during treatment, and any co-existing helminth infection should be addressed before starting.

Monitoring

Monitor asthma control, exacerbation frequency, polyp/sinonasal symptom scores and for hypersensitivity, reassessing benefit periodically against agreed response criteria.

Counselling the patient

This is an add-on treatment; keep taking your regular inhalers and other prescribed medicines.
Do not use it for sudden breathing difficulty or an asthma attack.
Report any rash, swelling or breathing difficulty after an injection.

Evidence & guidelines

Tezepelumab reduces exacerbations in severe asthma across phenotypes and is supported in UK practice through specialist severe-asthma and emerging CRSwNP pathways.

Reference: NAVIGATOR trial (Menzies-Gow et al. NEJM 2021); NICE TA879; MHRA SPC Tezspire 2022; WAYPOINT trial (CRSwNP, ongoing); ESMO/ERS Guidelines; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. The structured dose values shown have been reviewed by a clinician. Monograph status: clinician-reviewed (2026-07-04).

Curated clinical cross-links plus same-class fallbacks.

Calculators

Pathways