Gefitinib Tablets

Epidermal growth factor receptor (EGFR) is expressed in both normal cells and tumor cells, and plays an important role in the growth and differentiation of cells. EGFR mutations (exon 19 deletion and exon 21L858R mutation) in non-small cell lung cancer cells can promote tumor cell growth, inhibit cell apoptosis, increase the production of angiogenic factors, and promote tumor metastasis. Gefitinib is a reversible inhibitor of wild-type and certain mutant EGFR, which can inhibit the autophosphorylation of EGFR receptor tyrosine, thereby further inhibiting downstream signal transduction and preventing EGFR-dependent cell proliferation. Gefitinib has a greater affinity for mutant EGFR (exon 19 deletion and exon 21L858R mutation) than for wild-type EGFR. Gefitinib can also inhibit IGF- and PDGF-mediated signal transduction at clinically relevant concentrations; the inhibitory effect of gefitinib on other tyrosine kinases is not yet clear.

The main ingredient of this product is gefitinib.

Brown film-coated tablets, white or off-white after removing the coating.

This product is suitable for the first-line treatment of patients with locally advanced or metastatic non-small cell lung cancer (NSCLC) with sensitive mutations in the epidermal growth factor receptor (EGFR) gene (see [Precautions]). The results of two large randomized controlled clinical trials showed that gefitinib combined with platinum-containing chemotherapy as the first-line treatment for locally advanced or metastatic non-small cell lung cancer (NSCLC) did not show clinical benefit, so this combination regimen is not recommended as a first-line treatment. This product can be tried as a single agent for the treatment of locally advanced or metastatic non-small cell lung cancer (NSCLC) that has failed at least one previous chemotherapy. This product is not recommended for patients with EGFR wild-type non-small cell lung cancer (NSCLC).

The recommended dose of this product is 250 mg (1 tablet), orally, once a day, on an empty stomach or with food. If a dose of this product is missed, it should be taken as soon as the patient remembers. If the next dose is less than 12 hours away, the patient should not take the missed dose. The patient should not take a double dose (two doses at one time) to make up for the missed dose. When the tablet cannot be administered whole, such as when the patient can only swallow liquids, the tablet can be dispersed in water. The tablet should be dispersed in half a cup of drinking water (non-carbonated beverage) without crushing, stirred until completely dispersed (about 15 minutes), and the solution should be drunk immediately. Rinse the cup with half a cup of water and drink the washings. This solution can also be given through a nasogastric tube. No dosage adjustment is required for the following conditions: age, weight, sex, race, renal function, and moderate to severe liver impairment caused by liver metastases. Dose adjustment: When patients experience intolerable diarrhea or skin adverse reactions, they can be resolved by short-term suspension of treatment (up to 14 days), followed by resumption of the daily dose of 250 mg (see [Adverse Reactions]). Use in children: There is currently no data on the safety and efficacy of this product in children or adolescents, so it is not recommended.

The most common adverse drug reactions (ADRs) (incidence > 20%) are diarrhea and skin reactions (including rash, acne, dry skin, and itching), which are generally seen within the first month after taking the drug and are usually reversible. About 10% of patients experience serious adverse drug reactions (according to the National Cancer Institute [NCI] Common Toxicity Criteria [CTC] grade 3 or 4). About 3% of patients discontinue treatment due to ADRs.

Patients with known severe allergic reaction to the active substance or any of the excipients of this product.

Precautions for children: There is currently no data on the safety and efficacy of this product for children or adolescents, so it is not recommended. Precautions for pregnancy and lactation: There is currently no data on the use of this product in pregnant women. When gefitinib is given at a dose that can produce maternal toxicity during the organogenesis period, an increased incidence of osteogenesis imperfecta can be observed in rats, and decreased fetal weight can be observed in rabbits. No malformations were observed in rats, and malformations were only observed in rabbits at doses that produce severe maternal toxicity. During treatment with this product, women of childbearing age should be advised to avoid pregnancy. Use during lactation During treatment with this product, nursing mothers should be advised to stop breastfeeding. There is currently no data on the use of this product in lactating women. It is not known whether gefitinib or its metabolites are secreted into human milk. However, when lactating rats were given 5 mg/kg gefitinib orally (0.2 times the clinical dose based on body surface area), gefitinib and some metabolites were widely secreted into breast milk. Administration of gefitinib 20 mg/kg/day (0.7 times the clinical dose based on body surface area) during pregnancy and delivery in rats reduced the survival rate of pups. Elderly precautions: Not yet determined.

In vitro studies on human liver microsomes confirmed that gefitinib is mainly metabolized by CYP3A4 of the hepatic cytochrome P-450 system. Therefore, gefitinib may interact with drugs that induce, inhibit, or metabolize the same hepatic drug enzyme. Animal studies have shown that gefitinib has little enzyme induction, and in vitro studies have shown that gefitinib can inhibit CYP2D6 to a limited extent. The following is a list of drugs or drug classes that produce or may produce clinically significant drug interactions with gefitinib: Drugs that affect gefitinib Proven interactions Drugs that inhibit CYP3A4 In healthy volunteers, gefitinib was co-administered with itraconazole (a CYP3A4 inhibitor), and the average AUC of gefitinib increased by 80%. Because adverse drug reactions are related to dose and exposure, this increase may be clinically significant. Although no studies on interactions with other CYP3A4 inhibitors have been conducted, drugs in this class, such as ketoconazole, clotrimazole, and Ritonovir, may also inhibit the metabolism of gefitinib. Drugs that increase gastric pH In a clinical study in healthy volunteers, co-administration of ranitidine at doses that significantly and continuously increased gastric pH to ≥5 decreased the mean AUC of gefitinib by 47%, which may reduce the efficacy of gefitinib. Rifampicin In healthy volunteers, co-administration of gefitinib with rifampicin (a known strong CYP3A4 inducer) decreased the mean AUC of gefitinib by 83% compared with monotherapy. Drugs that may theoretically interact Other CYP3A4 inducers Substances that induce CYP3A4 activity can increase the metabolism of gefitinib and reduce its plasma concentrations. Therefore, co-administration with CYP3A4 inducers (such as phenytoin, carbamazepine, barbiturates, or St. John's wort) may reduce efficacy. Effects of gefitinib on other drugs Demonstrated interactions Drugs metabolized by CYP2D6 In a clinical trial, co-administration of gefitinib with metoprolol (a CYP2D6 substrate) increased the exposure of metoprolol by 35%, which was considered not to be clinically relevant. Taking gefitinib with other drugs metabolized by CYP2D6 may increase the latter's blood concentration. Drugs that may theoretically interact with warfarin Although no formal drug interaction studies have been conducted so far, increased INR and/or bleeding events have been reported in some patients taking warfarin. Patients taking warfarin should regularly monitor changes in their prothrombin time or INR (see [Precautions]). Vinorelbine In a Phase II clinical study, taking this product simultaneously with vinorelbine showed that this product may aggravate the neutropenia caused by vinorelbine.

Store below 30°C.

0.25 grams.

24 months.

Qilu Pharmaceutical (Hainan) Co., Ltd.

• Founded in:

  2005-10-18

• Address:

  No. 273-A, Nanhai Avenue, National High-tech Zone, Haikou City

• Tax NO.:

  91460000780701210W

• Registered Funds:

  40 million yuan

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