SIDE EFFECTS
The following adverse reactions are discussed in greater
detail in other sections of the label:
- Cardiomyopathy [see WARNINGS AND PRECAUTIONS]
- Infusion Reactions [see WARNINGS AND PRECAUTIONS]
- Embryo-Fetal Toxicity [see WARNINGS AND PRECAUTIONS]
- Pulmonary Toxicity [see WARNINGS AND PRECAUTIONS]
- Exacerbation of Chemotherapy-induced Neutropenia [see WARNINGS
AND PRECAUTIONS]
The most common adverse reactions in patients receiving
trastuzumab products in the adjuvant and metastatic breast cancer setting are
fever, nausea, vomiting, infusion reactions, diarrhea, infections, increased
cough, headache, fatigue, dyspnea, rash, neutropenia, anemia, and myalgia.
Adverse reactions requiring interruption or discontinuation of trastuzumab
product treatment include CHF, significant decline in left ventricular cardiac
function, severe infusion reactions, and pulmonary toxicity [see DOSAGE AND
ADMINISTRATION].
In the metastatic gastric cancer setting, the most common
adverse reactions (≥ 10%) that were increased (≥ 5% difference) in
patients receiving trastuzumab products as compared to patients receiving
chemotherapy alone were neutropenia, diarrhea, fatigue, anemia, stomatitis,
weight loss, upper respiratory tract infections, fever, thrombocytopenia,
mucosal inflammation, nasopharyngitis, and dysgeusia. The most common adverse
reactions which resulted in discontinuation of trastuzumab product treatment in
the absence of disease progression were infection, diarrhea, and febrile
neutropenia.
Clinical Trials Experience
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.
Adjuvant Breast Cancer Studies
The data below reflect exposure to one-year trastuzumab
therapy across three randomized, open-label studies, Studies 1, 2, and 3, with
(n = 3678) or without (n = 3363) trastuzumab in the adjuvant treatment of
breast cancer.
The data summarized in Table 3 below, from Study 3,
reflect exposure to trastuzumab in 1678 patients; the median treatment duration
was 51 weeks and median number of infusions was 18. Among the 3386 patients
enrolled in the observation and one-year trastuzumab arms of Study 3 at a median
duration of follow-up of 12.6 months in the trastuzumab arm, the median age was
49 years (range: 21 to 80 years), 83% of patients were Caucasian, and 13% were
Asian.
Table 3 : Adverse Reactions for Study 3a,
All Gradesb
Adverse Reaction |
One year Trastuzumab
(n = 1678) |
Observation
(n = 1708) |
Cardiac |
Hypertension |
64 (4%) |
35 (2%) |
Dizziness |
60 (4%) |
29 (2%) |
Ejection Fraction Decreased |
58 (3.5%) |
11 (0.6%) |
Palpitations |
48 (3%) |
12 (0.7%) |
Cardiac Arrhythmiasc |
40 (3%) |
17 (1%) |
Cardiac Failure Congestive |
30 (2%) |
5 (0.3%) |
Cardiac Failure |
9 (0.5%) |
4 (0.2%) |
Cardiac Disorder |
5 (0.3%) |
0 (0%) |
Ventricular Dysfunction |
4 (0.2%) |
0 (0%) |
Respiratory Thoracic Mediastinal Disorders |
Cough |
81 (5%) |
34 (2%) |
Influenza |
70 (4%) |
9 (0.5%) |
Dyspnea |
57 (3%) |
26 (2%) |
URI |
46 (3%) |
20 (1%) |
Rhinitis |
36 (2%) |
6 (0.4%) |
Pharyngolaryngeal Pain |
32 (2%) |
8 (0.5%) |
Sinusitis |
26 (2%) |
5 (0.3%) |
Epistaxis |
25 (2%) |
1 (0.06%) |
Pulmonary Hypertension |
4 (0.2%) |
0 (0%) |
Interstitial Pneumonitis |
4 (0.2%) |
0 (0%) |
Gastrointestinal Disorders |
Diarrhea |
123 (7%) |
16 (1%) |
Nausea |
108 (6%) |
19 (1%) |
Vomiting |
58 (3.5%) |
10 (0.6%) |
Constipation |
33 (2%) |
17 (1%) |
Dyspepsia |
30 (2%) |
9 (0.5%) |
Upper Abdominal Pain |
29 (2%) |
15 (1%) |
Musculoskeletal & Connective Tissue Disorders |
Arthralgia |
137 (8%) |
98 (6%) |
Back Pain |
91 (5%) |
58 (3%) |
Myalgia |
63 (4%) |
17 (1%) |
Bone Pain |
49 (3%) |
26 (2%) |
Muscle Spasm |
46 (3%) |
3 (0.2%) |
Nervous System Disorders |
Headache |
162 (10%) |
49 (3%) |
Paraesthesia |
29 (2%) |
11 (0.6%) |
Skin & Subcutaneous Tissue Disorders |
Rash |
70 (4%) |
10 (0.6%) |
Nail Disorders |
43 (2%) |
0 (0%) |
Pruritus |
40 (2%) |
10 (0.6%) |
General Disorders |
Pyrexia |
100 (6%) |
6 (0.4%) |
Edema Peripheral |
79 (5%) |
37 (2%) |
Chills |
85 (5%) |
0 (0%) |
Asthenia |
75 (4.5%) |
30 (2%) |
Influenza-like Illness |
40 (2%) |
3 (0.2%) |
Sudden Death |
1 (0.06%) |
0 (0%) |
Infections |
Nasopharyngitis |
135 (8%) |
|
UTI |
39 (3%) |
|
Immune System Disorders |
Hypersensitivity |
10 (0.6%) |
1 (0.06%) |
Autoimmune Thyroiditis |
4 (0.3%) |
0 (0%) |
a Median follow-up duration of 12.6 months in
the one-year trastuzumab treatment arm.
bThe incidence of Grade 3 or higher adverse reactions was < 1% in
both arms for each listed term.
c Higher level grouping term. |
In Study 3, a comparison of 3-weekly trastuzumab
treatment for two years versus one year was also performed. The rate of
asymptomatic cardiac dysfunction was increased in the 2-year trastuzumab
treatment arm (8.1% versus 4.6% in the one-year trastuzumab treatment arm).
More patients experienced at least one adverse reaction of Grade 3 or higher in
the 2-year trastuzumab treatment arm (20.4%) compared with the one-year
trastuzumab treatment arm (16.3%).
The safety data from Studies 1 and 2 were obtained from
3655 patients, of whom 2000 received trastuzumab; the median treatment duration
was 51 weeks. The median age was 49 years (range: 24 to 80); 84% of patients
were White, 7% Black, 4% Hispanic, and 3% Asian.
In Study 1, only Grade 3 to 5 adverse events,
treatment-related Grade 2 events, and Grade 2-5 dyspnea were collected
during and for up to 3 months following protocol-specified treatment. The
following non-cardiac adverse reactions of Grade 2 to 5 occurred at an
incidence of at least 2% greater among patients receiving trastuzumab plus
chemotherapy as compared to chemotherapy alone: fatigue (29.5% vs. 22.4%),
infection (24.0% vs. 12.8%), hot flashes (17.1% vs. 15.0%), anemia (12.3% vs. 6.7%),
dyspnea (11.8% vs. 4.6%), rash/desquamation (10.9% vs. 7.6%), leukopenia (10.5%
vs. 8.4%), neutropenia (6.4% vs. 4.3%), headache (6.2% vs. 3.8%), pain (5.5%
vs. 3.0%), edema (4.7% vs. 2.7%) and insomnia (4.3% vs. 1.5%). The majority of
these events were Grade 2 in severity.
In Study 2, data collection was limited to the following
investigator-attributed treatment-related adverse reactions: NCI-CTC Grade 4
and 5 hematologic toxicities, Grade 3 to 5 non-hematologic toxicities, selected
Grade 2 to 5 toxicities associated with taxanes (myalgia, arthralgias, nail
changes, motor neuropathy, sensory neuropathy) and Grade 1 to 5 cardiac
toxicities occurring during chemotherapy and/or trastuzumab treatment. The
following non-cardiac adverse reactions of Grade 2 to 5 occurred at an
incidence of at least 2% greater among patients receiving trastuzumab plus
chemotherapy as compared to chemotherapy alone: arthralgia (12.2% vs. 9.1%),
nail changes (11.5% vs.6.8%), dyspnea (2.4% vs. 0.2%), and diarrhea (2.2% vs.
0%). The majority of these events were Grade 2 in severity.
Safety data from Study 4 reflect exposure to trastuzumab
as part of an adjuvant treatment regimen from 2124 patients receiving at least
one dose of study treatment [AC-TH: n = 1068; TCH: n = 1056]. The overall
median treatment duration was 54 weeks in both the AC-TH and TCH arms. The
median number of infusions was 26 in the AC-TH arm and 30 in the TCH arm,
including weekly infusions during the chemotherapy phase and every three week
dosing in the monotherapy period. Among these patients, the median age was 49
years (range 22 to 74 years). In Study 4, the toxicity profile was similar to
that reported in Studies 1, 2, and 3 with the exception of a low incidence of
CHF in the TCH arm.
Metastatic Breast Cancer Studies
The data below reflect exposure to trastuzumab in one
randomized, open-label study, Study 5, of chemotherapy with (n = 235) or
without (n = 234) trastuzumab in patients with metastatic breast cancer, and
one single-arm study (Study 6; n = 222) in patients with metastatic breast
cancer. Data in Table 4 are based on Studies 5 and 6.
Among the 464 patients treated in Study 5, the median age
was 52 years (range: 25 to 77 years). Eighty-nine percent were White, 5% Black,
1% Asian and 5% other racial/ethnic groups. All patients received 4 mg/kg
initial dose of trastuzumab followed by 2 mg/kg weekly. The percentages of
patients who received trastuzumab treatment for ≥6 months and ≥12
months were 58% and 9%, respectively.
Among the 352 patients treated in single agent studies
(213 patients from Study 6), the median age was 50 years (range 28 to 86
years), 86% were White, 3% were Black, 3% were Asian, and 8% in other
racial/ethnic groups. Most of the patients received 4 mg/kg initial dose of
trastuzumab followed by 2 mg/kg weekly. The percentages of patients who
received trastuzumab treatment for ≥6 months and ≥12 months were
31% and 16%, respectively.
Table 4 : Per-Patient Incidence of Adverse Reactions
Occurring in ≥5% of Patients in Uncontrolled Studies or at Increased
Incidence in the Trastuzumab Arm (Studies 5 and 6)
|
Single Agenta
n = 352 |
Trastuzumab + Paclitaxel
n = 91 |
Paclitaxel Alone
n = 95 |
Trastuzumab + ACb
n = 143 |
ACb Alone
n = 135 |
Body as a Whole |
Pain |
47% |
61% |
62% |
57% |
42% |
Asthenia |
42% |
62% |
57% |
54% |
55% |
Fever |
36% |
49% |
23% |
56% |
34% |
Chills |
32% |
41% |
4% |
35% |
11% |
Headache |
26% |
36% |
28% |
44% |
31% |
Abdominal pain |
22% |
34% |
22% |
23% |
18% |
Back pain |
22% |
34% |
30% |
27% |
15% |
Infection |
20% |
47% |
27% |
47% |
31% |
Flu syndrome |
10% |
12% |
5% |
12% |
6% |
Accidental injury |
6% |
13% |
3% |
9% |
4% |
Allergic reaction |
3% |
8% |
2% |
4% |
2% |
Cardiovascular |
Tachycardia |
5% |
12% |
4% |
10% |
5% |
Congestive heart failure |
7% |
11% |
1% |
28% |
7% |
Digestive |
Nausea |
33% |
51% |
9% |
76% |
77% |
Diarrhea |
25% |
45% |
29% |
45% |
26% |
Vomiting |
23% |
37% |
28% |
53% |
49% |
Nausea and vomiting |
8% |
14% |
11% |
18% |
9% |
Anorexia |
14% |
24% |
16% |
31% |
26% |
Heme & Lymphatic |
Anemia |
4% |
14% |
9% |
36% |
26% |
Leukopenia |
3% |
24% |
17% |
52% |
34% |
Metabolic |
Peripheral edema |
10% |
22% |
20% |
20% |
17% |
Edema |
8% |
10% |
8% |
11% |
5% |
Musculoskeletal |
Bone pain |
7% |
24% |
18% |
7% |
7% |
Arthralgia |
6% |
37% |
21% |
8% |
9% |
Nervous |
Insomnia |
14% |
25% |
13% |
29% |
15% |
Dizziness |
13% |
22% |
24% |
24% |
18% |
Paresthesia |
9% |
48% |
39% |
17% |
11% |
Depression |
6% |
12% |
13% |
20% |
12% |
Peripheral neuritis |
2% |
23% |
16% |
2% |
2% |
Neuropathy |
1% |
13% |
5% |
4% |
4% |
Respiratory |
Cough increased |
26% |
41% |
22% |
43% |
29% |
Dyspnea |
22% |
27% |
26% |
42% |
25% |
Rhinitis |
14% |
22% |
5% |
22% |
16% |
Pharyngitis |
12% |
22% |
14% |
30% |
18% |
Sinusitis |
9% |
21% |
7% |
13% |
6% |
Skin |
Rash |
18% |
38% |
18% |
27% |
17% |
Herpes simplex |
2% |
12% |
3% |
7% |
9% |
Acne |
2% |
11% |
3% |
3% |
< 1% |
Urogenital |
Urinary tract infection |
5% |
18% |
14% |
13% |
7% |
a Data for Trastuzumab single agent were from
4 studies, including 213 patients from Study 6.
bAnthracycline (doxorubicin or epirubicin) and cyclophosphamide. |
Metastatic Gastric Cancer
The data below are based on the exposure of 294 patients
to trastuzumab in combination with a fluoropyrimidine (capecitabine or 5-FU)
and cisplatin (Study 7). In the trastuzumab plus chemotherapy arm, the initial
dose of trastuzumab 8 mg/kg was administered on Day 1 (prior to chemotherapy)
followed by 6 mg/kg every 21 days until disease progression. Cisplatin was administered
at 80 mg/m² on Day 1 and the fluoropyrimidine was administered as either
capecitabine 1000 mg/m² orally twice a day on Days 1 to14 or 5-fluorouracil 800
mg/m²/day as a continuous intravenous infusion Days 1 through 5. Chemotherapy
was administered for six 21 day cycles. Median duration of trastuzumab
treatment was 21 weeks; median number of trastuzumab infusions administered was
eight.
Table 5 : Study 7: Per Patient Incidence of Adverse
Reactions of All Grades (Incidence ≥ 5% between Arms) or Grade 3/4
(Incidence > 1 % between Arms) and Higher Incidence in Trastuzumab Arm
Body System/Adverse Event |
Trastuzumab + FC
(N = 294) N (%) |
FC
(N = 290) N (%) |
All Grades |
Grades 3/4 |
All Grades |
Grades 3/4 |
Investigations |
Neutropenia |
230 (78) |
101 (34) |
212 (73) |
83 (29) |
Hypokalemia |
83 (28) |
28 (10) |
69 (24) |
16 (6) |
Anemia |
81 (28) |
36 (12) |
61 (21) |
30 (10) |
Thrombocytopenia |
47 (16) |
14 (5) |
33 (11) |
8 (3) |
Blood and Lymphatic System Disorders |
Febrile Neutropenia |
- |
15 (5) |
- |
8 (3) |
Gastrointestinal Disorders |
Diarrhea |
109 (37) |
27 (9) |
80 (28) |
11 (4) |
Stomatitis |
72 (24) |
2 (1) |
43 (15) |
6 (2) |
Dysphagia |
19 (6) |
7 (2) |
10 (3) |
1 (< 1) |
Body as a Whole |
Fatigue |
102 (35) |
12 (4) |
82 (28) |
7 (2) |
Fever |
54 (18) |
3 (1) |
36 (12) |
0 (0) |
Mucosal Inflammation |
37 (13) |
6 (2) |
18 (6) |
2 (1) |
Chills |
23 (8) |
1 (< 1) |
0 (0) |
0 (0) |
Metabolism and Nutrition Disorders |
Weight Decrease |
69 (23) |
6 (2) |
40 (14) |
7 (2) |
Infections and Infestations |
Upper Respiratory Tract Infections |
56 (19) |
0 (0) |
29 (10) |
0 (0) |
Nasopharyngitis |
37 (13) |
0 (0) |
17 (6) |
0 (0) |
Renal and Urinary Disorders |
Renal Failure and Impairment |
53 (18) |
8 (3) |
42 (15) |
5 (2) |
Nervous System Disorders |
Dysgeusia |
28 (10) |
0 (0) |
14 (5) |
0 (0) |
The following subsections provide additional detail
regarding adverse reactions observed in clinical trials of adjuvant breast
cancer, metastatic breast cancer, metastatic gastric cancer, or post-marketing
experience.
Cardiomyopathy
Serial measurement of cardiac function (LVEF) was
obtained in clinical trials in the adjuvant treatment of breast cancer. In
Study 3, the median duration of follow-up was 12.6 months (12.4 months in the
observation arm; 12.6 months in the 1-year trastuzumab arm); and in Studies 1
and 2, 7.9 years in the AC-T arm, 8.3 years in the AC-TH arm. In Studies 1 and
2, 6% of all randomized patients with post-AC LVEF evaluation were not
permitted to initiate trastuzumab following completion of AC chemotherapy due to
cardiac dysfunction (LVEF < LLN or ≥ 16 point decline in LVEF from
baseline to end of AC). Following initiation of trastuzumab therapy, the
incidence of new-onset dose-limiting myocardial dysfunction was higher among
patients receiving trastuzumab and paclitaxel as compared to those receiving
paclitaxel alone in Studies 1 and 2, and in patients receiving one-year
trastuzumab monotherapy compared to observation in Study 3 (see Table 6,
Figures 1 and 2). The per-patient incidence of new-onset cardiac dysfunction,
as measured by LVEF, remained similar when compared to the analysis performed
at a median follow-up of 2.0 years in the AC-TH arm. This analysis also showed
evidence of reversibility of left ventricular dysfunction, with 64.5% of
patients who experienced symptomatic CHF in the AC-TH group being asymptomatic
at latest follow-up, and 90.3% having full or partial LVEF recovery.
Table 6a : Per-patient
Incidence of New Onset Myocardial Dysfunction (by LVEF) Studies 1, 2, 3 and 4
|
LVEF <50% and Absolute Decrease from Baseline |
Absolute LVEF Decrease |
LVEF < 50% |
≥ 10% decrease |
≥ 16% decrease |
< 20% and ≥10% |
≥20% |
Studies 1 & 2b,c |
AC →TH |
23.1% |
18.5% |
11.2% |
37.9% |
8.9% |
(n = 1856) |
(428) |
(344) |
(208) |
(703) |
(166) |
AC →T |
11.7% |
7.0% |
3.0% |
22.1% |
3.4% |
(n =1170) |
(137) |
(82) |
(35) |
(259) |
(40) |
Study 3d |
Trastuzumab |
8.6% |
7.0% |
3.8% |
22.4% |
3.5% |
(n = 1678) |
(144) |
(118) |
(64) |
(376) |
(59) |
Observation |
2.7% |
2.0% |
1.2% |
11.9% |
1.2% |
(n = 1708) |
(46) |
(35) |
(20) |
(204) |
(21) |
Study 4e |
TCH |
8.5% |
5.9% |
3.3% |
34.5% |
6.3% |
(n = 1056) |
(90) |
(62) |
(35) |
(364) |
(67) |
AC →TH |
17% |
13.3% |
9.8% |
44.3% |
13.2% |
(n = 1068) |
(182) |
(142) |
(105) |
(473) |
(141) |
AC → T |
9.5% |
6.6% |
3.3% |
34% |
5.5% |
(n =1050) |
(100) |
(69) |
(35) |
(357) |
(58) |
a For Studies 1, 2 and 3, events are counted
from the beginning of trastuzumab treatment. For Study 4, events are counted
from the date of randomization.
bStudies 1 and 2 regimens: doxorubicin and cyclophosphamide followed
by paclitaxel (AC → T) or paclitaxel plus trastuzumab (AC → TH).
c Median duration of follow-up for Studies 1 and 2 combined was 8.3
years in the AC → TH arm.
dMedian follow-up duration of 12.6 months in the one-year
trastuzumab treatment arm.
e Study 4 regimens: doxorubicin and cyclophosphamide followed by
docetaxel (AC → T) or docetaxel plus trastuzumab (AC → TH);
docetaxel and carboplatin plus trastuzumab (TCH). |
Figure 1 : Studies 1 and 2: Cumulative Incidence of
Time to First LVEF Decline of ≥ 10 Percentage Points from Baseline and to
Below 50% with Death as a Competing Risk Event
Time 0 is initiation of paclitaxel or trastuzumab +
paclitaxel therapy.
Figure 2 : Study 3: Cumulative Incidence of Time to
First LVEF Decline of ≥ 10 Percentage Points from Baseline and to Below
50% with Death as a Competing Risk Event
Time 0 is the date of randomization.
Figure 3 : Study 4: Cumulative Incidence of Time to
First LVEF Decline of ≥ 10 Percentage Points from Baseline and to Below
50% with Death as a Competing Risk Event
Time 0 is the date of randomization.
The incidence of treatment emergent congestive heart
failure among patients in the metastatic breast cancer trials was classified
for severity using the New York Heart Association classification system
(I-IV, where IV is the most severe level of cardiac failure) (see Table
2). In the metastatic breast cancer trials, the probability of cardiac dysfunction
was highest in patients who received trastuzumab concurrently with
anthracyclines.
In Study 7, 5.0% of patients in the trastuzumab plus
chemotherapy arm compared to 1.1% of patients in the chemotherapy alone arm had
LVEF value below 50% with a ≥ 10% absolute decrease in LVEF from
pretreatment values.
Infusion Reactions
During the first infusion with trastuzumab, the symptoms
most commonly reported were chills and fever, occurring in approximately 40% of
patients in clinical trials. Symptoms were treated with acetaminophen,
diphenhydramine, and meperidine (with or without reduction in the rate of
trastuzumab infusion); permanent discontinuation of trastuzumab for infusion
reactions was required in < 1% of patients. Other signs and/or symptoms may
include nausea, vomiting, pain (in some cases at tumor sites), rigors,
headache, dizziness, dyspnea, hypotension, elevated blood pressure, rash, and
asthenia. Infusion reactions occurred in 21% and 35% of patients, and were
severe in 1.4% and 9% of patients, on second or subsequent trastuzumab
infusions administered as monotherapy or in combination with chemotherapy,
respectively. In the post-marketing setting, severe infusion reactions,
including hypersensitivity, anaphylaxis, and angioedema have been reported.
Anemia
In randomized controlled clinical trials, the overall
incidence of anemia (30% vs. 21% [Study 5]), of selected NCI-CTC Grade 2 to 5
anemia (12.3% vs. 6.7% [Study 1]), and of anemia requiring transfusions (0.1%
vs. 0 patients [Study 2]) were increased in patients receiving trastuzumab and
chemotherapy compared with those receiving chemotherapy alone. Following the
administration of trastuzumab as a single agent (Study 6), the incidence of
NCI-CTC Grade 3 anemia was < 1%. In Study 7 (metastatic gastric cancer), on
the trastuzumab containing arm as compared to the chemotherapy alone arm, the
overall incidence of anemia was 28% compared to 21% and of NCI-CTC Grade 3/4
anemia was 12.2% compared to 10.3%.
Neutropenia
In randomized controlled clinical trials in the adjuvant
setting, the incidence of selected NCI-CTC Grade 4 to 5 neutropenia (1.7% vs.
0.8% [Study 2]) and of selected Grade 2 to 5 neutropenia (6.4% vs. 4.3% [Study
1]) were increased in patients receiving trastuzumab and chemotherapy compared
with those receiving chemotherapy alone. In a randomized, controlled trial in
patients with metastatic breast cancer, the incidences of NCI-CTC Grade 3/4
neutropenia (32% vs. 22%) and of febrile neutropenia (23% vs. 17%) were also
increased in patients randomized to trastuzumab in combination with
myelosuppressive chemotherapy as compared to chemotherapy alone. In Study 7
(metastatic gastric cancer) on the trastuzumab containing arm as compared to
the chemotherapy alone arm, the incidence of NCI-CTC Grade 3/4 neutropenia was
36.8% compared to 28.9%; febrile neutropenia 5.1% compared to 2.8%.
Infection
The overall incidences of infection (46% vs. 30% [Study
5]), of selected NCI-CTC Grade 2 to 5 infection/febrile neutropenia (24.3% vs.
13.4% [Study 1]) and of selected Grade 3 to 5 infection/febrile neutropenia
(2.9% vs. 1.4%) [Study 2]) were higher in patients receiving trastuzumab and
chemotherapy compared with those receiving chemotherapy alone. The most common
site of infections in the adjuvant setting involved the upper respiratory
tract, skin, and urinary tract.
In Study 4, the overall incidence of infection was higher
with the addition of trastuzumab to AC-T but not to TCH [44% (AC-TH), 37%
(TCH), 38% (AC-T)]. The incidences of NCI-CTC Grade 3 to 4 infection were
similar [25% (AC-TH), 21% (TCH), 23% (AC-T)] across the three arms.
In a randomized, controlled trial in treatment of
metastatic breast cancer, the reported incidence of febrile neutropenia was
higher (23% vs. 17%) in patients receiving trastuzumab in combination with
myelosuppressive chemotherapy as compared to chemotherapy alone.
Pulmonary Toxicity
Adjuvant Breast Cancer
Among women receiving adjuvant therapy for breast cancer,
the incidence of selected NCI-CTC Grade 2 to 5 pulmonary toxicity (14.3% vs.
5.4% [Study 1]) and of selected NCI-CTC Grade 3 to 5 pulmonary toxicity and
spontaneous reported Grade 2 dyspnea (3.4 % vs. 0.9% [Study 2]) was higher in
patients receiving trastuzumab and chemotherapy compared with chemotherapy
alone. The most common pulmonary toxicity was dyspnea (NCI-CTC Grade 2 to 5:
11.8% vs. 4.6% [Study 1]; NCI-CTC Grade 2 to 5: 2.4% vs. 0.2% [Study 2]).
Pneumonitis/pulmonary infiltrates occurred in 0.7% of
patients receiving trastuzumab compared with 0.3% of those receiving
chemotherapy alone. Fatal respiratory failure occurred in 3 patients receiving
trastuzumab, one as a component of multi-organ system failure, as compared to 1
patient receiving chemotherapy alone.
In Study 3, there were 4 cases of interstitial pneumonitis
in the one-year trastuzumab treatment arm compared to none in the observation
arm at a median follow-up duration of 12.6 months.
Metastatic Breast Cancer
Among women receiving trastuzumab for treatment of
metastatic breast cancer, the incidence of pulmonary toxicity was also
increased. Pulmonary adverse events have been reported in the post-marketing
experience as part of the symptom complex of infusion reactions. Pulmonary
events include bronchospasm, hypoxia, dyspnea, pulmonary infiltrates, pleural
effusions, noncardiogenic pulmonary edema, and acute respiratory distress
syndrome. For a detailed description, see WARNINGS AND PRECAUTIONS.
Thrombosis/Embolism
In 4 randomized, controlled clinical trials, the
incidence of thrombotic adverse events was higher in patients receiving
trastuzumab and chemotherapy compared to chemotherapy alone in three studies
(2.6% vs. 1.5% [Study 1], 2.5% and 3.7% vs. 2.2% [Study 4] and 2.1% vs. 0%
[Study 5]).
Diarrhea
Among women receiving adjuvant therapy for breast cancer,
the incidence of NCI-CTC Grade 2 to 5 diarrhea (6.7% vs. 5.4% [Study 1]) and of
NCI-CTC Grade 3 to 5 diarrhea (2.2% vs. 0% [Study 2]), and of Grade 1 to 4
diarrhea (7% vs. 1% [Study 3; one-year trastuzumab treatment at 12.6 months
median duration of follow-up]) were higher in patients receiving trastuzumab as
compared to controls. In Study 4, the incidence of Grade 3 to 4 diarrhea was
higher [5.7% ACTH, 5.5% TCH vs. 3.0% AC-T] and of Grade 1 to 4 was higher [51%
AC-TH, 63% TCH vs. 43% AC-T] among women receiving trastuzumab. Of patients
receiving trastuzumab as a single agent for the treatment of metastatic breast
cancer, 25% experienced diarrhea. An increased incidence of diarrhea was
observed in patients receiving trastuzumab in combination with chemotherapy for
treatment of metastatic breast cancer.
Renal Toxicity
In Study 7 (metastatic gastric cancer) on the
trastuzumab-containing arm as compared to the chemotherapy alone arm the
incidence of renal impairment was 18% compared to 14.5%. Severe (Grade 3/4)
renal failure was 2.7% on the trastuzumab-containing arm compared to 1.7% on
the chemotherapy only arm. Treatment discontinuation for renal
insufficiency/failure was 2% on the trastuzumab-containing arm and 0.3% on the
chemotherapy only arm.
In the post-marketing setting, rare cases of nephrotic
syndrome with pathologic evidence of glomerulopathy have been reported. The
time to onset ranged from 4 months to approximately 18 months from initiation
of trastuzumab therapy. Pathologic findings included membranous
glomerulonephritis, focal glomerulosclerosis, and fibrillary
glomerulonephritis. Complications included volume overload and congestive heart
failure.
Immunogenicity
As with all therapeutic proteins, there is a potential
for immunogenicity. The detection of antibody formation is highly dependent on
the sensitivity and the specificity of the assay. Additionally, the observed
incidence of antibody (including neutralizing antibody) positivity in an assay
may be influenced by several factors including assay methodology, sample
handling, timing of sample collection, concomitant medications, and underlying
disease. For these reasons, comparison of the incidence of antibodies in the
studies described below with the incidence of antibodies in other studies or to
other trastuzumab products may be misleading. Among 903 women with metastatic
breast cancer, human anti-human antibody (HAHA) to trastuzumab was detected in
one patient using an enzyme-linked immunosorbent assay (ELISA). This patient
did not experience an allergic reaction. Samples for assessment of HAHA were
not collected in studies of adjuvant breast cancer.
Post-Marketing Experience
The following adverse reactions have been identified
during post-approval use of trastuzumab. 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.
- Infusion reaction [see WARNINGS AND PRECAUTIONS]
- Oligohydramnios or oligohydramnios sequence, including
pulmonary hypoplasia, skeletal abnormalities, and neonatal death [see WARNINGS
AND PRECAUTIONS]
- Glomerulopathy [see ADVERSE REACTIONS]
- Immune thrombocytopenia
DRUG INTERACTIONS
Patients who receive anthracycline after stopping
trastuzumab products may be at increased risk of cardiac dysfunction because of
trastuzumab's long washout period based on population PK analysis [see CLINICAL
PHARMACOLOGY]. If possible, physicians should avoid anthracyclinebased
therapy for up to 7 months after stopping trastuzumab products. If
anthracyclines are used, the patient's cardiac function should be monitored
carefully.