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 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 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 |
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%) |
43 (3%) |
UTI |
39 (3%) |
13 (0.8%) |
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.
b The 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 to 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, and
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.
b Anthracycline (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 to 14 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
(n = 1856) |
23.1% (428) |
18.5% (344) |
11.2% (208) |
37.9% (703) |
8.9% (166) |
AC→T
(n = 1170) |
11.7% (137) |
7.0% (82) |
3.0% (35) |
22.1% (259) |
3.4% (40) |
Study 3d |
Trastuzumab
(n = 1678) |
8.6% (144) |
7.0% (118) |
3.8% (64) |
22.4% (376) |
3.5% (59) |
Observation
(n = 1708) |
2.7% (46) |
2.0% (35) |
1.2% (20) |
11.9% (204) |
1.2% (21) |
Study 4e |
TCH
(n = 1056) |
8.5% (90) |
5.9% (62) |
3.3% (35) |
34.5% (364) |
6.3% (67) |
AC→TH
(n = 1068) |
17% (182) |
13.3% (142) |
9.8% (105) |
44.3% (473) |
13.2% (141) |
AC→T
(n = 1050) |
9.5% (100) |
6.6% (69) |
3.3% (35) |
34% (357) |
5.5% (58) |
aFor 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.
b Studies 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.
d Median 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, non-cardiogenic 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% AC-TH, 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 potential for immunogenicity. The detection of antibody formation is highly dependent on the sensitivity and 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 Clinical Trials Experience]
- Immune thrombocytopenia
- Tumor lysis syndrome (TLS): Cases of possible TLS have been reported in patients treated with trastuzumab products. Patients with significant tumor burden (e.g. bulky metastases) may be at a higher risk. Patients could present with hyperuricemia, hyperphosphatemia, and acute renal failure which may represent possible TLS. Providers should consider additional monitoring and/or treatment as clinically indicated.
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 anthracycline-based therapy for up to 7 months after stopping trastuzumab products. If anthracyclines are used, the patient's cardiac function should be monitored carefully.