IRESSA

What it is

IRESSA contains 250 mg of gefitinib per tablet. It is supplied as film-coated tablets that are brown, round, and biconvex, impressed with "IRESSA 250" on one side. Gefitinib is a selective inhibitor of the epidermal growth factor receptor (EGFR) tyrosine kinase, commonly expressed in solid human tumours of epithelial origin.

Approved indications

— Treatment of patients with locally advanced or metastatic Non-Small Cell Lung Cancer (NSCLC) whose tumours express activating mutations of the EGFR tyrosine kinase.

Dosing overview

The recommended dose of IRESSA is one 250 mg tablet once a day, taken with or without food. For patients who are only able to swallow liquids, tablets may be administered as a dispersion in water by dropping the tablet into half a glass of drinking water, stirring until dispersed (approximately 15 minutes), and drinking immediately, then rinsing the glass with a further half glass of water and drinking the contents. The liquid can also be administered via a nasogastric tube.

Key safety warnings

Interstitial Lung Disease (ILD), which may be acute in onset, has been observed in patients receiving IRESSA, and some cases have been fatal. Patients typically have an acute onset of dyspnoea associated with cough, low grade fever, respiratory distress and arterial oxygen desaturation, and symptoms may become severe within a short time. If patients present with worsening of respiratory symptoms such as dyspnoea, cough and fever, IRESSA should be interrupted and prompt investigation initiated. If ILD is confirmed, IRESSA should be discontinued. Patients presenting with signs and symptoms suggestive of keratitis such as acute or worsening eye inflammation, lacrimation, light sensitivity, blurred vision, eye pain and/or red eye should be referred promptly to an ophthalmology specialist. If a diagnosis of ulcerative keratitis is confirmed, treatment with IRESSA should be interrupted, and if symptoms do not resolve, or recur on reintroduction of IRESSA, permanent discontinuation should be considered. Gastrointestinal perforation has been reported in patients taking IRESSA. In most cases this is associated with other known risk factors, including increasing age, concomitant medications such as steroids or NSAIDs, underlying history of GI ulceration, smoking or bowel metastases at sites of perforation. Severe cutaneous reactions including erythema multiforme and life-threatening reactions such as Stevens-Johnson syndrome or toxic epidermal necrolysis have been reported with gefitinib. Treatment should be interrupted if the patient develops severe bullous, blistering or exfoliative conditions, and discontinued if Stevens-Johnson syndrome or toxic epidermal necrolysis are confirmed. Liver function test abnormalities have been observed, uncommonly presenting as hepatitis. There have been isolated reports of hepatic failure which in some cases led to fatal outcomes. Therefore, periodic liver function testing is recommended.

Contraindications

Known severe hypersensitivity to the active substance or to any of the excipients of this product.

Regulatory history

IRESSA gefitinib 250 mg tablet was first listed on the Australian Register of Therapeutic Goods on 28 April 2003.