(dacomitinib)

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12 CLINICAL PHARMACOLOGY

12 CLINICAL PHARMACOLOGY

12.1 Mechanism of Action

Dacomitinib is an irreversible inhibitor of the kinase activity of the human EGFR family (EGFR/HER1, HER2, and HER4) and certain EGFR activating mutations (exon 19 deletion or the exon 21 L858R substitution mutation). In vitro dacomitinib also inhibited the activity of DDR1, EPHA6, LCK, DDR2, and MNK1 at clinically relevant concentrations.

Dacomitinib demonstrated dose-dependent inhibition of EGFR and HER2 autophosphorylation and tumor growth in mice bearing subcutaneously implanted human tumor xenografts driven by HER family targets including mutated EGFR. Dacomitinib also exhibited antitumor activity in orally-dosed mice bearing intracranial human tumor xenografts driven by EGFR amplifications.

12.2 Pharmacodynamics

Cardiac Electrophysiology

The effect of dacomitinib on the QT interval corrected for heart rate (QTc) was evaluated using time-matched electrocardiograms (ECGs) evaluating the change from baseline and corresponding pharmacokinetic data in 32 patients with advanced NSCLC. Dacomitinib had no large effect on QTc (i.e., >20 ms) at maximum dacomitinib concentrations achieved with VIZIMPRO 45 mg orally once daily.

Exposure-Response Relationships

Higher exposures, across the range of exposures with the recommended dose of 45 mg daily, correlated with an increased probability of Grade ≥3 adverse events, specifically dermatologic toxicities and diarrhea.

12.3 Pharmacokinetics

The maximum dacomitinib plasma concentration (Cmax) and AUC at steady state increased proportionally over the dose range of VIZIMPRO 2 mg to 60 mg orally once daily (0.04 to 1.3 times the recommended dose) across dacomitinib studies in patients with cancer. At a dose of 45 mg orally once daily, the geometric mean [coefficient of variation (CV%)] Cmax was 108 ng/mL (35%) and the AUC0–24h was 2213 ng∙h/mL (35%) at steady state in a dose-finding clinical study conducted in patients with solid tumors. Steady state was achieved within 14 days following repeated dosing and the estimated geometric mean (CV%) accumulation ratio was 5.7 (28%) based on AUC.

Absorption

The mean absolute bioavailability of dacomitinib is 80% after oral administration. The median dacomitinib time to reach maximum concentration (Tmax) occurred at approximately 6.0 hours (range 2.0 to 24 hours) after a single oral dose of VIZIMPRO 45 mg in patients with cancer.

Effect of Food

Administration of VIZIMPRO with a high-fat, high-calorie meal (approximately 800 to 1000 calories with 150, 250, and 500 to 600 calories from protein, carbohydrate and fat, respectively) had no clinically meaningful effect on dacomitinib pharmacokinetics.

Distribution

The geometric mean (CV%) volume of distribution of dacomitinib (Vss) was 1889 L (18%). In vitro binding of dacomitinib to human plasma proteins is approximately 98% and is independent of drug concentrations from 250 ng/mL to 1000 ng/mL.

Elimination

Following a single 45 mg oral dose of VIZIMPRO in patients with cancer, the mean (CV%) plasma half-life of dacomitinib was 70 hours (21%), and the geometric mean (CV%) apparent plasma clearance of dacomitinib was 24.9 L/h (36%).

Metabolism

Hepatic metabolism is the main route of clearance of dacomitinib, with oxidation and glutathione conjugation as the major pathways. Following oral administration of a single 45 mg dose of [14C] dacomitinib, the most abundant circulating metabolite was O-desmethyl dacomitinib, which had similar in vitro pharmacologic activity as dacomitinib. The steady-state plasma trough concentration of O-desmethyl dacomitinib ranges from 7.4% to 19% of the parent. In vitro studies indicated that cytochrome P450 (CYP) 2D6 was the major isozyme involved in the formation of O-desmethyl dacomitinib, while CYP3A4 contributed to the formation of other minor oxidative metabolites.

Excretion

Following a single oral 45 mg dose of [14C] radiolabeled dacomitinib, 79% of the radioactivity was recovered in feces (20% as dacomitinib) and 3% in urine (<1% as dacomitinib).

Specific Populations

Patients with Renal Impairment

Based on population pharmacokinetic analyses, mild (60 mL/min ≤ CLcr <90 mL/min; N=590) and moderate (30 mL/min ≤ CLcr <60 mL/min; N=218) renal impairment did not alter dacomitinib pharmacokinetics, relative to the pharmacokinetics in patients with normal renal function (CLcr ≥90 mL/min; N=567). The pharmacokinetics of dacomitinib has not been adequately characterized in patients with severe renal impairment (CLcr <30 mL/min) (N=4) or studied in patients requiring hemodialysis.

Patients with Hepatic Impairment

No clinically significant differences in the pharmacokinetics of dacomitinib were observed in subjects with mild, moderate or severe hepatic impairment (Child-Pugh A, B or C) [see Use in Specific Populations (8.7)].

Drug Interaction Studies

Clinical Studies

Effect of Acid-Reducing Agents on Dacomitinib

Coadministration of a single 45 mg dose of VIZIMPRO with multiple doses of rabeprazole (a proton pump inhibitor) decreased dacomitinib Cmax by 51% and AUC0–96h by 39% [see Dosage and Administration (2.4) and Drug Interactions (7.1)].

Coadministration of VIZIMPRO with a local antacid (Maalox® Maximum Strength, 400 mg/5 mL) did not cause clinically relevant changes dacomitinib concentrations [see Dosage and Administration (2.4) and Drug Interactions (7.1)].

The effect of H2 receptor antagonists on dacomitinib pharmacokinetics has not been studied [see Dosage and Administration (2.4) and Drug Interactions (7.1)].

Effect of Strong CYP2D6 Inhibitors on Dacomitinib

Coadministration of a single 45 mg dose of VIZIMPRO with multiple doses of paroxetine (a strong CYP2D6 inhibitor) in healthy subjects increased the total AUClast of dacomitinib plus its active metabolite (O-desmethyl dacomitinib) in plasma by approximately 6%, which is not considered clinically relevant.

Effect of Dacomitinib on CYP2D6 Substrates

Coadministration of a single 45 mg oral dose of VIZIMPRO increased dextromethorphan (a CYP2D6 substrate) Cmax by 9.7-fold and AUClast by 9.6-fold [see Drug Interactions (7.2)].

In Vitro Studies

Effect of Dacomitinib and O-desmethyl Dacomitinib on CYP Enzymes: Dacomitinib and its metabolite O-desmethyl dacomitinib do not inhibit CYP1A2, CYP2B6, CYP2C8, CYP2C9, CYP2C19, or CYP3A4/5. Dacomitinib does not induce CYP1A2, CYP2B6, or CYP3A4.

Effect of Dacomitinib on Uridine 5' diphospho-glucuronosyltransferase (UGT) Enzymes: Dacomitinib inhibits UGT1A1. Dacomitinib does not inhibit UGT1A4, UGT1A6, UGT1A9, UGT2B7, or UGT2B15.

Effect of Dacomitinib on Transporter Systems: Dacomitinib is a substrate for the membrane transport protein P-glycoprotein (P-gp) and Breast Cancer Resistance Protein (BCRP). Dacomitinib inhibits P-gp, BCRP, and organic cation transporter (OCT)1. Dacomitinib does not inhibit organic anion transporters (OAT)1 and OAT3, OCT2, organic anion transporting polypeptide (OATP)1B1, and OATP1B3.

Medication Guide

MEDICATION GUIDE

This Patient Information has been approved by the U.S. Food and Drug Administration.Issued: September 2018
PATIENT INFORMATION
VIZIMPRO® (
vih-ZIM-pro)
(dacomitinib)

tablets
What is VIZIMPRO?
VIZIMPRO is a prescription medicine used to treat non-small cell lung cancer (NSCLC) that has spread to other parts of the body (metastatic):
  • As your first treatment if your tumor has certain types of abnormal epidermal growth factor receptor (EGFR) gene(s).
Your healthcare provider will perform a test to make sure that VIZIMPRO is right for you.
It is not known if VIZIMPRO is safe and effective in children.
Before taking VIZIMPRO, tell your healthcare provider about all your medical conditions, including if you:
  • have frequent diarrhea.
  • have a history of lung or breathing problems other than lung cancer.
  • are pregnant, or plan to become pregnant. VIZIMPRO can harm your unborn baby.
Females who are able to become pregnant:
 
  • Your healthcare provider should do a pregnancy test before you start treatment with VIZIMPRO.
  • You should use effective birth control (contraception) during treatment and for at least 17 days after your last dose of VIZIMPRO. Talk to your healthcare provider about birth control methods that may be right for you during this time.
  • Tell your healthcare provider right away if you become pregnant during your treatment with VIZIMPRO.
  • are breastfeeding or plan to breastfeed. It is not known if VIZIMPRO passes into your breast milk. Do not breastfeed during treatment and for at least 17 days after your last dose of VIZIMPRO. Talk to your healthcare provider about the best way to feed your baby during this time.
Tell your healthcare provider about all of the medicines you take, including prescription and over-the-counter medicines, vitamins, and herbal supplements. VIZIMPRO and other medicines or supplements may affect each other causing side effects.
How should I take VIZIMPRO?
  • Take VIZIMPRO exactly as your healthcare provider tells you.
  • Take your dose at approximately the same time each day.
  • Your healthcare provider may change your dose, temporarily stop, or permanently stop treatment with VIZIMPRO if you have side effects.
  • Take VIZIMPRO 1 time each day with or without food.
  • If you take an antacid or H2 blocker medicine during treatment with VIZIMPRO, take your dose of VIZIMPRO at least 6 hours before or 10 hours after taking the antacid or H2 blocker medicine. Do not change your dose or stop taking VIZIMPRO unless your healthcare provider tells you.
  • If you vomit or miss a dose of VIZIMPRO, do not take another dose or make up for the missed dose. Take your next dose at your regular time.
What should I avoid during treatment with VIZIMPRO?
What are the possible side effects of VIZIMPRO?
VIZIMPRO may cause serious side effects, including:
  • Lung or breathing problems. VIZIMPRO may cause severe inflammation of the lung that may lead to death. Symptoms may be similar to those symptoms from lung cancer. Tell your healthcare provider right away if you have any new or worsening lung symptoms, including trouble breathing or shortness of breath, cough, or fever.
  • Diarrhea. Diarrhea is common during treatment with VIZIMPRO, and can be severe and lead to death. Diarrhea can cause you to lose too much body fluid (dehydration). Your healthcare provider may tell you to start drinking more fluids or start taking your anti-diarrheal medicines. Tell your healthcare provider right away, if you have any loose stools or have stools more often than is normal for you.
  • Skin reactions. Skin reactions are common with VIZIMPRO and can be severe. These skin reactions may include: dry skin, redness, rash, acne, itching, and peeling or blistering of your skin. Use moisturizers every day when taking VIZIMPRO. Use sunscreen and wear protective clothing that covers your skin, while exposed to sunlight, while you are taking VIZIMPRO. Your healthcare provider may prescribe other medicines to help skin reactions. Tell your healthcare provider right away about any worsening skin reactions.
The most common side effects of VIZIMPRO include:
  • rash
  • diarrhea
  • mouth pain and sores
  • nail inflammation
  • common cold
  • dry skin
  • decreased appetite
  • decreased weight
  • dry, red, itchy eyes
  • hair loss
  • itching
Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.
How should I store VIZIMPRO?
  • Store VIZIMPRO at 20 °C to 25 °C (68 °F to 77 °F).
Keep VIZIMPRO and all medicines out of the reach of children.
General information about the safe and effective use of VIZIMPRO.
Medicines are sometimes prescribed for purposes other than those listed in a Patient Information leaflet. Do not use VIZIMPRO for a condition for which it was not prescribed. Do not give VIZIMPRO to other people, even if they have the same symptoms you have. It may harm them.
You can ask your pharmacist or healthcare provider for more information about VIZIMPRO that is written for health professionals.
What are the ingredients in VIZIMPRO?
Active ingredient:
dacomitinib
Inactive ingredients: lactose monohydrate, microcrystalline cellulose, sodium starch glycolate, and magnesium stearate.
Film coating contains: Opadry II® Blue 85F30716 containing: Polyvinyl alcohol – partially hydrolyzed, Talc, Titanium dioxide, Macrogol/PEG 3350, and FD&C Blue #2/Indigo Carmine Aluminum Lake.

Logo

LAB-1238-1.0
For more information, go to www.VIZIMPRO.com or call 1-800-438-1985.

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