TYKERB Film-coated tablet Ref.[11065] Active ingredients: Lapatinib

5.1 Decreased Left Ventricular Ejection Fraction

TYKERB has been reported to decrease LVEF [see Adverse Reactions (6.1)]. In clinical trials, the majority (greater than 57%) of LVEF decreases occurred within the first 12 weeks of treatment; however, data on long-term exposure are limited. Caution should be taken if TYKERB is to be administered to patients with conditions that could impair left ventricular function. LVEF should be evaluated in all patients prior to initiation of treatment with TYKERB to ensure that the patient has a baseline LVEF that is within the institution’s normal limits. LVEF should continue to be evaluated during treatment with TYKERB to ensure that LVEF does not decline below the institution’s normal limits [see Dosage and Administration (2.2)].

5.2 Hepatotoxicity

Hepatotoxicity [alanine aminotransferase (ALT) or aspartate aminotransferase (AST) greater than 3 times the upper limit of normal (ULN) and total bilirubin greater than 2 times the ULN] has been observed in clinical trials (less than 1% of patients) and postmarketing experience. The hepatotoxicity may be severe and deaths have been reported. Causality of the deaths is uncertain. The hepatotoxicity may occur days to several months after initiation of treatment. Liver function tests (transaminases, bilirubin, and alkaline phosphatase) should be monitored before initiation of treatment, every 4 to 6 weeks during treatment, and as clinically indicated. If changes in liver function are severe, therapy with TYKERB should be discontinued and patients should not be retreated with TYKERB [see Adverse Reactions (6.1)].

5.3 Patients With Severe Hepatic Impairment

If TYKERB is to be administered to patients with severe preexisting hepatic impairment, dose reduction should be considered [see Dosage and Administration (2.2) and Use in Specific Populations (8.7)]. In patients who develop severe hepatotoxicity while on therapy, TYKERB should be discontinued and patients should not be retreated with TYKERB [see Warnings and Precautions (5.2)].

5.4 Diarrhea

Diarrhea has been reported during treatment with TYKERB [see Adverse Reactions (6.1)]. The diarrhea may be severe, and deaths have been reported. Diarrhea generally occurs early during treatment with TYKERB, with almost half of those patients with diarrhea first experiencing it within 6 days. This usually lasts 4 to 5 days. TYKERB-induced diarrhea is usually low-grade, with severe diarrhea of NCI CTCAE Grades 3 and 4 occurring in less than 10% and less than 1% of patients, respectively. Early identification and intervention is critical for the optimal management of diarrhea. Patients should be instructed to report any change in bowel patterns immediately. Prompt treatment of diarrhea with antidiarrheal agents (such as loperamide) after the first unformed stool is recommended. Severe cases of diarrhea may require administration of oral or intravenous electrolytes and fluids, use of antibiotics such as fluoroquinolones (especially if diarrhea is persistent beyond 24 hours, there is fever, or Grade 3 or 4 neutropenia), and interruption or discontinuation of therapy with TYKERB [see Dosage and Administration (2.2)].

5.5 Interstitial Lung Disease/Pneumonitis

TYKERB has been associated with interstitial lung disease and pneumonitis in monotherapy or in combination with other chemotherapies [see Adverse Reactions (6.1)]. Patients should be monitored for pulmonary symptoms indicative of interstitial lung disease or pneumonitis. TYKERB should be discontinued in patients who experience pulmonary symptoms indicative of interstitial lung disease/pneumonitis, which are greater than or equal to Grade 3 (NCI CTCAE v3.0).

5.6 QT Prolongation

A concentration-dependent QT prolongation has been associated with TYKERB [see Clinical Pharmacology (12.2)]. Monitor patients who have or may develop prolongation of QTc during treatment with TYKERB. These conditions include patients with hypokalemia or hypomagnesemia, with congenital long QT syndrome, patients taking antiarrhythmic medicines or other medicinal products with known risk for QT prolongation/Torsades de Pointes (TdP), and cumulative high-dose anthracycline therapy. Correct hypokalemia or hypomagnesemia prior to TYKERB administration.

5.7 Severe Cutaneous Reactions

Severe cutaneous reactions have been reported with TYKERB. If life-threatening reactions such as erythema multiforme, Stevens-Johnson syndrome, or toxic epidermal necrolysis (e.g., progressive skin rash often with blisters or mucosal lesions) are suspected, discontinue treatment with TYKERB.

5.8 Embryo-Fetal Toxicity

Based on its mechanism of action and findings in animal studies, TYKERB can cause fetal harm when administered to a pregnant woman. In animal reproductive studies, administration of lapatinib to pregnant rats during the period of organogenesis and through lactation led to death of offspring within the first 4 days after birth at maternal exposures that were ≥3.3 times the human clinical exposure based on AUC following 1,250 mg dose of lapatinib plus capecitabine. When administered to pregnant animals during the period of organogenesis, lapatinib caused fetal anomalies (rats) or abortions (rabbits) at maternally toxic doses (with maternal exposures approximately 6.4 and 0.2 times, respectively, the human clinical exposure based on AUC following 1,250 mg dose of lapatinib plus capecitabine).

Advise pregnant women and females of reproductive potential of the potential risk to the fetus [see Use in Specific Populations (8.1) and Clinical Pharmacology (12.1)]. Verify the pregnancy status of females of reproductive potential prior to initiation of TYKERB. Advise females of reproductive potential to use effective contraception during treatment with TYKERB and for 1 week after the last dose. Advise male patients with female partners of reproductive potential to use effective contraception during treatment with TYKERB and for 1 week after the last dose [see Use in Specific Populations (8.1, 8.3)].

Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice.

HER2-Positive Metastatic Breast Cancer

The safety of TYKERB has been evaluated in more than 12,000 patients in clinical trials. The efficacy and safety of TYKERB in combination with capecitabine in breast cancer was evaluated in 198 patients in a randomized, Phase 3 trial [see Clinical Studies (14.1)]. Adverse reactions, which occurred in at least 10% of patients in either treatment arm and were higher in the combination arm, are shown in Table 1.

The most common adverse reactions (greater than 20%) during therapy with TYKERB plus capecitabine were gastrointestinal (diarrhea, nausea, and vomiting), dermatologic (palmar-plantar erythrodysesthesia and rash), and fatigue. Diarrhea was the most common adverse reaction resulting in discontinuation of study medication.

The most common Grade 3 and 4 adverse reactions (NCI CTCAE v3.0) were diarrhea and palmar-plantar erythrodysesthesia. Selected laboratory abnormalities are shown in Table 2.

Table 1. Adverse Reactions Occurring in Greater Than or Equal to 10% of Patients:

^a NCI CTCAE v3.0.
^b Grade 3 dermatitis acneiform was reported in less than 1% of patients in the group receiving TYKERB plus capecitabine.

Table 2. Selected Laboratory Abnormalities:

Abbreviations: ALT, alanine aminotransferase; AST, aspartate aminotransferase.
^a NCI CTCAE v3.0.

Hormone Receptor-Positive, Metastatic Breast Cancer: In a randomized, Phase 3 clinical trial of patients (N = 1286) with hormone receptor-positive, metastatic breast cancer, who had not received chemotherapy for their metastatic disease, patients received letrozole with or without TYKERB. In this trial, the safety profile of TYKERB was consistent with previously reported results from trials of TYKERB in the advanced or metastatic breast cancer population. Adverse reactions, which occurred in at least 10% of patients in either treatment arm and were higher in the combination arm are shown in Table 3. Selected laboratory abnormalities are shown in Table 4.

Table 3. Adverse Reactions Occurring in Greater Than or Equal to 10% of Patients:

^a NCI CTCAE v3.0.
^b In addition to the rash reported under “Skin and subcutaneous tissue disorders”, 3 additional subjects in each treatment arm had rash under “Infections and infestations”; none were Grade 3 or 4.

Table 4. Selected Laboratory Abnormalities:

Abbreviations: ALT, alanine aminotransferase; AST, aspartate aminotransferase.
^a NCI CTCAE v3.0.

Hormone Receptor-Positive, HER2+ Metastatic Breast Cancer

In another randomized, Phase 3 clinical trial of postmenopausal patients (N=355) with hormone receptor positive (HR+), HER2-positive metastatic breast cancer (MBC) which had progressed after prior trastuzumab-containing chemotherapy and endocrine therapies, patients received TYKERB with trastuzumab and an aromatase inhibitor (AI) (letrozole, exemestane, or anastrozole), TYKERB with an AI, or trastuzumab with an AI. In this trial, the safety profile of the treatment groups was consistent with the known safety of these agents. The most frequent study treatment-related AEs (>10%) in each of the TYKERB-containing treatment arms were diarrhea, rash, paronychia, nausea, stomatitis, dermatitis acneiform, and decreased appetite, which were infrequent to absent in the trastuzumab treatment arm. The frequency of cardiac AEs (mostly decrease in ejection fraction) was 7% in the TYKERB+trastuzumab+AI group, 2% in the TYKERB+AI group and 3% in the trastuzumab+AI group. Adverse reactions which occurred in at least 10% of patients in the treatment arms are shown in Table 5.

Table 5. Adverse Reactions Occurring in Greater Than or Equal to 10% of Patients:

^a NCI CTCAE v3.0.
^b Includes multiple adverse reaction terms for rash.

Decreases in Left Ventricular Ejection Fraction

Due to potential cardiac toxicity with HER2 (ErbB2) inhibitors, LVEF was monitored in clinical trials at approximately 8-week intervals. LVEF decreases were defined as signs or symptoms of deterioration in left ventricular cardiac function that are greater than or equal to Grade 3 (NCI CTCAE v3.0), or a greater than or equal to 20% decrease in left ventricular cardiac ejection fraction relative to baseline which is below the institution’s lower limit of normal. Among 198 patients who received combination treatment with TYKERB/capecitabine, 3 experienced Grade 2 and one had Grade 3 LVEF adverse reactions (NCI CTCAE v3.0). Among 654 patients who received combination treatment with TYKERB/letrozole, 26 patients experienced Grade 1 or 2 and 6 patients had Grade 3 or 4 LVEF adverse reactions [see Warnings and Precautions (5.1)].

Hepatotoxicity

TYKERB has been associated with hepatotoxicity [see Boxed Warning and Warnings and Precautions (5.2)].

Interstitial Lung Disease/Pneumonitis

TYKERB has been associated with interstitial lung disease and pneumonitis in monotherapy or in combination with other chemotherapies [see Warnings and Precautions (5.5)].

The following adverse reactions have been identified during post-approval use of TYKERB. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure.

Immune System Disorders: Hypersensitivity reactions including anaphylaxis [see Contraindications (4)].

Skin and Subcutaneous Tissue Disorders: Nail disorders including paronychia. Severe cutaneous adverse reactions including Stevens Johnson Syndrome (SJS) and toxic epidermal necrolysis (TEN).

Cardiac Disorders: Ventricular arrhythmias/Torsades de Pointes (TdP). Electrocardiogram (ECG) QT prolongation.

7.1 Effects of Lapatinib on Drug-Metabolizing Enzymes and Drug Transport Systems

Lapatinib inhibits CYP3A4, CYP2C8, and P-glycoprotein (P-gp, ABCB1) in vitro at clinically relevant concentrations and is a weak inhibitor of CYP3A4 in vivo. Caution should be exercised and dose reduction of the concomitant substrate drug should be considered when dosing TYKERB concurrently with medications with narrow therapeutic windows that are substrates of CYP3A4, CYP2C8, or P-gp. Lapatinib did not significantly inhibit the following enzymes in human liver microsomes: CYP1A2, CYP2C9, CYP2C19, and CYP2D6 or UGT enzymes in vitro, however, the clinical significance is unknown.

Midazolam

Following coadministration of TYKERB and midazolam (CYP3A4 substrate), 24-hour systemic exposure (AUC) of orally administered midazolam increased 45%, while 24-hour AUC of intravenously administered midazolam increased 22%.

Paclitaxel

In cancer patients receiving TYKERB and paclitaxel (CYP2C8 and P-gp substrate), 24-hour systemic exposure (AUC) of paclitaxel was increased 23%. This increase in paclitaxel exposure may have been underestimated from the in vivo evaluation due to study design limitations.

Digoxin

Following coadministration of TYKERB and digoxin (P-gp substrate), systemic AUC of an oral digoxin dose increased approximately 2.8-fold. Serum digoxin concentrations should be monitored prior to initiation of TYKERB and throughout coadministration. If digoxin serum concentration is greater than 1.2 ng/mL, the digoxin dose should be reduced by half.

7.2 Drugs That Inhibit or Induce Cytochrome P450 3A4 Enzymes

Lapatinib undergoes extensive metabolism by CYP3A4, and concomitant administration of strong inhibitors or inducers of CYP3A4 alter lapatinib concentrations significantly (see Ketoconazole and Carbamazepine sections, below). Dose adjustment of TYKERB should be considered for patients who must receive concomitant strong inhibitors or concomitant strong inducers of CYP3A4 enzymes [see Dosage and Administration (2.2)].

Ketoconazole

In healthy subjects receiving ketoconazole, a CYP3A4 inhibitor, at 200 mg twice daily for 7 days, systemic exposure (AUC) to lapatinib was increased to approximately 3.6-fold of control and half-life increased to 1.7-fold of control.

Carbamazepine

In healthy subjects receiving the CYP3A4 inducer, carbamazepine, at 100 mg twice daily for 3 days and 200 mg twice daily for 17 days, systemic exposure (AUC) to lapatinib was decreased approximately 72%.

7.3 Drugs That Inhibit Drug Transport Systems

Lapatinib is a substrate of the efflux transporter P-glycoprotein (P-gp, ABCB1). If TYKERB is administered with drugs that inhibit P-gp, increased concentrations of lapatinib are likely, and caution should be exercised.

7.4 Acid-Reducing Agents

The aqueous solubility of lapatinib is pH dependent, with higher pH resulting in lower solubility. However, esomeprazole, a proton pump inhibitor, administered at a dose of 40 mg once daily for 7 days, did not result in a clinically meaningful reduction in lapatinib steady-state exposure.

Risk Summary

Based on findings in animal studies and its mechanism of action, TYKERB can cause fetal harm when administered to a pregnant woman [see Clinical Pharmacology (12.1)]. There are no available human data to inform of the drug-associated risks. In an animal reproduction study, administration of lapatinib to pregnant rats during organogenesis and through lactation led to death of offspring within the first 4 days after birth at maternal exposures that were ≥3.3 times the human clinical exposure based on AUC following 1,250 mg dose of lapatinib plus capecitabine. When administered to pregnant animals during the period of organogenesis, lapatinib caused fetal anomalies (rats) or abortions (rabbits) at maternally toxic doses (see Data).

Advise pregnant women and females of reproductive potential of the potential risk to the fetus.

The background risk of major birth defects and miscarriage for the indicated population is unknown; however, in the U.S. general population, the estimated background risk of major birth defects is 2%-4% and of miscarriage is 15%-20% of clinically recognized pregnancies.

Data

Animal Data

In embryo-fetal development studies in rats and rabbits, pregnant animals received oral doses of lapatinib at 30, 60, and 120 mg/kg/day during the period of organogenesis. Minor anomalies (left-sided umbilical artery, cervical rib, and precocious ossification) occurred in rats at the maternally toxic dose of 120 mg/kg/day (approximately 6.4 times the human clinical exposure based on AUC following 1,250 mg dose of lapatinib plus capecitabine). In rabbits, lapatinib was associated with maternal toxicity at 60 and 120 mg/kg/day (approximately 0.07 and 0.2 times the human clinical exposure, respectively, based on AUC following 1,250 mg dose of lapatinib plus capecitabine) and abortions at 120 mg/kg/day. Maternal toxicity was associated with decreased fetal body weights and minor skeletal variations.

In a pre- and post-natal development study, rats were given oral doses of 20, 60, and 120 mg/kg/day during gestation through lactation up to weaning. In rats, doses of 60 and 120 mg/kg/day (approximately 3.3 and 6.4 times the human clinical exposure, respectively, based on AUC following 1,250 mg dose of lapatinib plus capecitabine) led to decrease in F1 postnatal survival (91% and 34% of the pups died by the fourth day after birth, at 60 and 120 mg/kg/day, respectively).

Risk Summary

There are no data on the presence of lapatinib in human milk, or its effects on the breastfed child, or milk production. Because of the potential for serious adverse reactions in a breastfed child from TYKERB, advise lactating women not to breastfeed during treatment with TYKERB and for 1 week after the last dose.

Pregnancy Testing

Verify the pregnancy status of females of reproductive potential prior to the initiation of TYKERB.

Contraception

Females

Based on findings in animal studies, TYKERB can cause fetal harm when administered to a pregnant woman [see Use in Specific Populations (8.1)]. Advise females of reproductive potential to use effective contraception during treatment with TYKERB and for 1 week after the last dose.

Males

Based on findings in animal reproduction studies, advise male patients with female partners of reproductive potential to use effective contraception during treatment with TYKERB and for 1 week after the last dose [see Use in Specific Populations (8.1)].

The safety and effectiveness of TYKERB in pediatric patients have not been established.

Of the total number of metastatic breast cancer patients in clinical studies of TYKERB in combination with capecitabine (N=198), 17% were 65 years of age and older, and 1% were 75 years of age and older. Of the total number of hormone receptor-positive, HER2-positive metastatic breast cancer patients in clinical studies of TYKERB in combination with letrozole (N=642), 44% were 65 years of age and older, and 12% were 75 years of age and older. No overall differences in safety or effectiveness were observed between elderly subjects and younger subjects, and other reported clinical experience has not identified differences in responses between the elderly and younger patients, but greater sensitivity of some older individuals cannot be ruled out.

Lapatinib pharmacokinetics have not been specifically studied in patients with renal impairment or in patients undergoing hemodialysis. There is no experience with TYKERB in patients with severe renal impairment. However, renal impairment is unlikely to affect the pharmacokinetics of lapatinib given that less than 2% (lapatinib and metabolites) of an administered dose is eliminated by the kidneys.

The pharmacokinetics of lapatinib were examined in subjects with preexisting moderate (n=8) or severe (n=4) hepatic impairment (Child-Pugh Class B/C, respectively) and in 8 healthy control subjects. Systemic exposure (AUC) to lapatinib after a single oral 100-mg dose increased approximately 14% and 63% in subjects with moderate and severe preexisting hepatic impairment, respectively. Administration of TYKERB in patients with severe hepatic impairment should be undertaken with caution due to increased exposure to the drug. A dose reduction should be considered for patients with severe preexisting hepatic impairment [see Dosage and Administration (2.2)]. In patients who develop severe hepatotoxicity while on therapy, TYKERB should be discontinued and patients should not be retreated with TYKERB [see Warnings and Precautions (5.2)].