The drug is a kinase agonist that is indicated as monotherapy for EFGR and tyrosine kinase suppressor-naive adult patients whose NSCLC is metastatic or locally advanced and the tumours are resistant to EGFR mutations as approved by an FDA-endorsed examination. In addition, the adult patients should indicate signs of squamous histology progress at the time of platinum-based chemotherapy or after the sessions.
Volume of Distribution
The volume of distribution of the drug in healthy volunteers is 4500 L. The high volume of transmission in plasma indicates that there could be a higher rate of distribution in body tissues.
Afatinib is an irreversible ErbB inhibitor that forms covalent bonds with the kinase domains of EGFR, HER4, and human EGFRs (HER) 2, which results in an irreparable obstruction of tyrosine kinase autophosphorylation.
Afatinib as a single treatment agent obstructs the ErbB receptor which influences tumour regression and also inhibits further growth of the tumour through deregulation of the ErbB pathway. NSCLC tumours with a characteristic activating EGFR variation (Del 19, L858R) and other uncommon variations in exon 21 (L861Q) and exon 18 (G719X) are responsive to treatment with Afatinib in both clinical and non-clinical setups. Limited clinical and non-clinical activity indicates NSCLC tumours with positioning mutations in exon 20.
The accession of a secondary T790M variation is a crucial trait of acquired resistance to the drug and gene dosage of T790M-possessing allele correlates with partial resistance in vitro. The T790M variation is highlighted in about 50% of the patient’s tumour’s whose development on Afatinib may be perceived as a next-line therapeutic option where the T790M aims at EGFR TKIs. Other mechanisms of resistance to the drug have been highlighted MET gene extension clinically and preclinically.
The impact of multiple doses of the drug (50 mg once per day) on the QTc interval and the cardiac electrophysiology was examined in a single-arm, open-label study in people with refractory or relapsed solid tumours. The study maintains that there were no developments in the mean QTc interval, >20 ms.
Afatinib is a prescription medicine that can be taken orally for the treatment of non-small cell lung cancer (NSCLC) with atypical Epidermal Growth Factor Receptor (EFGR) agents. Afatinib is also prescribed for the treatment of NSCLC with the potential or radiating to other body tissues other than the lungs (metastatic cancer) as detected through an FDA approved examination. Afatinib is a 4-anilinoquinazoline tyrosine kinase suppressor that is available as a dimaleate salt (brand name: Giltrif). The drug is the first FDA-endorsed oncology product by Boehringer Ingelheim.
An oral administration of Afatinib attains peak plasma concentrations after 2-5 hours. The geometric mean relative bioavailability of 20mg tablets is 92% as opposed to the oral syrup. Systemic exposure to the drug is reduced by 50% and 30%, Cmax and AUC0-∞ respectively, when taken with a high-fat meal as opposed to its administration after a period of fasting. The population pharmacokinetic data obtained from several clinical trials on tumours suggests that there is an average reduction of 26% in AUCss if a patient consumes food about 1-3 hours prior to the administration of Afatinib.
Common side effects associated with the administration of Afatinib include conjunctivitis, fever, runny nose, bloody nose, bladder/urinary tract infection, itching, vomiting, weight loss, loss of appetite nausea, acne, dry skin, skin infections around toenails or fingernails, mouth sores, chapped lips, inflammation of the lips and the mouth, blisters or skin lesions, skin rash, and diarrhoea.
Adverse reactions to Afatinib may include Keratitis, hepatic toxicity, Interstitial Lung Disease, Exfoliative and Bullous Skin Disorders, and diarrhoea.
Route of Elimination
The elimination of Afatinib in humans is primarily through the faecal route. The administration of an oral solution of the drug suggests that about 85.4 % of Afatinib is recovered in faeces whereas 4.3% of the drug in urine.
Information on Dosing
The recommended dose of Afatinib is 40mg administered orally once every day 1-2 hours after the consumption of a meal, until the tumours regress or if the patient’s body can no longer tolerate the drug.
Metabolic reactions that are catalyzed by enzymes play an insignificant role in the synthesis of Afatinib. Covalent bonds to proteins are the fundamental forms of the drug’s metabolites.
An aminocrotonylamino-substituted quinazoline derivative
ChEBI: A quinazoline compound having a 3-chloro-4-fluoroanilino group at the 4-position, a 4-dimethylamino-trans-but-2-enamido group at the 6-position, and an (S)-tetrahydrofuran-3-yloxy group at the 7-position. Used (as its di
aleate salt) for the first-line treatment of patients with metastatic non-small cell lung cancer.
Afatinib may interact with phenobarbital, St. Johns wort, phenytoin, carbamazepine, rifampicin, saquinavir, nelfinavir, tacrolimus, quinidine, itraconazole, amiodarone, verapamil, ketoconazole, cyclosporine A. or erythromycin. This is not an all-inclusive list of all the drugs that may interact with Afatinib hence a patient should always notify their healthcare provider of any herbal supplements, over-the-counter drugs and other medications they are taking prior to the initiation of treatment.
Afatinib may also harm a developing fetus hence it is not recommended during pregnancy.