follitropin delta: clinical use

Prescribing considerations

• Initiate under a clinician experienced in fertility treatment, with suitable ultrasound and laboratory monitoring available.
• Assess infertility and contraindications to pregnancy before treatment; evaluate and manage thyroid dysfunction and hyperprolactinaemia where relevant.
• Individualisation uses recent serum AMH measured with a supported assay and current body weight.
• Record the product name and batch number for biological-medicine traceability.
• Consider OHSS, thromboembolic and ovarian torsion risks.

Contraindications and cautions

• Hypersensitivity to follitropin delta or an excipient.
• Hypothalamic or pituitary tumour.
• Ovarian enlargement or cyst not caused by polycystic ovary syndrome.
• Unexplained gynaecological bleeding.
• Ovarian, uterine or breast carcinoma.
• Primary ovarian failure.
• Reproductive-organ malformation or uterine fibroid incompatible with pregnancy.

Monitoring

• Regular ultrasound assessment of follicular development, with or without serum oestradiol.
• Clinical surveillance for excessive ovarian response and OHSS, including after final follicular maturation.
• Review thromboembolic risk factors and promptly assess possible thrombosis or ovarian torsion.
• Record ovarian response to inform decisions in any later treatment cycle.

Clinical pharmacology

Follitropin delta is recombinant human FSH with subunit amino-acid sequences identical to endogenous FSH. Subcutaneous bioavailability is about 64%; exposure is inversely related to body weight, and elimination is expected to be mainly renal.

Formulation and product differences

• The product is a clear, colourless multidose solution in a pre-filled pen supplied with injection needles.
• Follitropin delta is expressed in micrograms; its product-specific potency and pen settings must not be converted directly from IU-based regimens for other gonadotrophins.
• The formulation contains phenol and polysorbate 20; polysorbates may cause allergic reactions.
• The formulation is essentially sodium-free.

Injection

Route: Parenteral

Strengths: 12 micrograms/0.36 mL, 36 micrograms/1.08 mL, 72 micrograms/2.16 mL