First-Line Combination Therapy
A total of 955 patients with metastatic colorectal cancer received the recommended
regimens of irinotecan in combination with 5-FU/LV, 5-FU/LV alone, or irinotecan
alone. In the two phase 3 studies, 370 patients received irinotecan in combination
with 5-FU/LV, 362 patients received 5-FU/LV alone, and 223 patients received irinotecan
alone. (See Table 10 in DOSAGE AND ADMINISTRATION for recommended combination-agent
regimens.)
In Study 1, 49 (7.3%) patients died within 30 days of last study treatment: 21 (9.3%) received irinotecan in combination with 5-FU/LV, 15 (6.8%) received 5-FU/LV alone, and 13 (5.8%) received irinotecan alone. Deaths potentially related to treatment occurred in 2 (0.9%) patients who received irinotecan in combination with 5-FU/LV (2 neutropenic fever/sepsis), 3 (1.4%) patients who received 5-FU/LV alone (1 neutropenic fever/sepsis, 1 CNS bleeding during thrombocytopenia, 1 unknown) and 2 (0.9%) patients who received irinotecan alone (2 neutropenic fever). Deaths from any cause within 60 days of first study treatment were reported for 15 (6.7%) patients who received irinotecan in combination with 5-FU/LV, 16 (7.3%) patients who received 5-FU/LV alone, and 15 (6.7%) patients who received irinotecan alone. Discontinuations due to adverse events were reported for 17 (7.6%) patients who received irinotecan in combination with 5FU/LV, 14 (6.4%) patients who received 5-FU/LV alone, and 26 (11.7%) patients who received irinotecan alone.
In Study 2, 10 (3.5%) patients died within 30 days of last study treatment: 6 (4.1%) received irinotecan in combination with
5-FU/LV and 4 (2.8%) received 5-FU/LV alone. There was one potentially treatment-related death, which occurred in
a patient who received irinotecan in combination with 5-FU/LV (0.7%, neutropenic sepsis). Deaths from any cause
within 60 days of first study treatment were reported for 3 (2.1%) patients who received irinotecan in combination
with 5-FU/LV and 2 (1.4%) patients who received 5-FU/LV alone. Discontinuations due to adverse events were reported for
9 (6.2%) patients who received irinotecan in combination with 5FU/LV and 1 (0.7%) patient who received 5-FU/LV alone.
The most clinically significant adverse events for patients receiving irinotecan-based therapy were diarrhea, nausea, vomiting, neutropenia, and alopecia. The most clinically significant adverse events for patients receiving 5-FU/LV therapy were diarrhea, neutropenia, neutropenic fever, and mucositis. In Study 1, grade 4 neutropenia, neutropenic fever (defined as grade 2 fever and grade 4 neutropenia), and mucositis were observed less often with weekly irinotecan/5-FU/LV than with monthly administration of 5-FU/LV.
Tables 6 and 7 list the clinically relevant adverse events reported in Studies 1
and 2, respectively.
Table 6. Study 1: Percent (%) of Patients Experiencing Clinically Relevant Adverse
Events in Combination Therapiesa
Table 7. Study 2: Percent (%) of Patients Experiencing Clinically Relevant Adverse
Events in Combination Therapiesa
Second-Line Single-Agent Therapy
Weekly Dosage Schedule
In three clinical studies evaluating the weekly dosage schedule, 304 patients with metastatic carcinoma of the colon or rectum that had recurred or progressed following 5-FU-based therapy were treated with CAMPTOSAR. Seventeen of the patients died within 30 days of the administration of CAMPTOSAR; in five cases (1.6%, 5/304), the deaths were potentially drug-related. These five patients experienced a constellation of medical events that included known effects of CAMPTOSAR. One of these patients died of neutropenic sepsis without fever. Neutropenic fever occurred in nine (3.0%) other patients; these patients recovered with supportive care.
One hundred nineteen (39.1%) of the 304 patients were hospitalized a total of 156 times because of adverse events; 81 (26.6%) patients were hospitalized for events judged to be related to administration of CAMPTOSAR. The primary reasons for drug-related hospitalization were diarrhea, with or without nausea and/or vomiting (18.4%); neutropenia/leukopenia, with or without diarrhea and/or fever (8.2%); and nausea and/or vomiting (4.9%).
Adjustments in the dose of CAMPTOSAR were made during the cycle of treatment and for subsequent cycles based on individual
patient tolerance. The first dose of at least one cycle of CAMPTOSAR was reduced for 67% of patients who
began the studies at the 125-mg/m2 starting dose. Within-cycle dose reductions were required for 32% of the cycles
initiated at the 125-mg/m2 dose level. The most common reasons for dose reduction were late diarrhea, neutropenia,
and leukopenia. Thirteen (4.3%) patients discontinued treatment with CAMPTOSAR because of adverse events. The adverse
events in Table 8 are based on the experience of the 304 patients enrolled in the three studies described in the
CLINICAL STUDIES, Studies Evaluating the Weekly Dosage Schedule, section.
Table 8. Adverse Events Occurring in >10% of 304 Previously Treated Patients with
Metastatic Carcinoma of the Colon or Rectuma
Once-Every-3-Week Dosage Schedule
A total of 535 patients with metastatic colorectal cancer whose disease had recurred
or progressed following prior 5-FU therapy participated in the two phase 3 studies:
316 received irinotecan, 129 received 5-FU, and 90 received best supportive care.
Eleven (3.5%) patients treated with irinotecan died within 30 days of treatment.
In three cases (1%, 3/316), the deaths were potentially related to irinotecan treatment
and were attributed to neutropenic infection, grade 4 diarrhea, and asthenia, respectively.
One (0.8%, 1/129) patient treated with 5-FU died within
30 days of treatment; this death was attributed to grade 4 diarrhea.
Hospitalizations due to serious adverse events (whether or not related to study
treatment) occurred at least once in 60% (188/316) of patients who received irinotecan,
63% (57/90) who received best supportive care, and 39% (50/129) who received 5-FU-based
therapy. Eight percent of patients treated with irinotecan and 7% treated with 5-FU-based
therapy discontinued treatment due to adverse events.
Of the 316 patients treated with irinotecan, the most clinically significant adverse
events (all grades, 1-4) were diarrhea (84%), alopecia (72%), nausea (70%), vomiting
(62%), cholinergic symptoms (47%), and neutropenia (30%). Table 9 lists the grade
3 and 4 adverse events reported in the patients enrolled to all treatment arms of
the two studies described in the CLINICAL STUDIES, Studies Evaluating the Once-Every-3-Week
Dosage Schedule, section.
Table 9. Percent Of Patients Experiencing Grade 3 & 4 Adverse Events ln Comparative
Studies Of Once-every-3-week Irinotecan Therapya
Overview of Adverse Events
Gastrointestinal: Nausea, vomiting, and diarrhea are common adverse events
following treatment with CAMPTOSAR and can be severe. When observed, nausea and
vomiting usually occur during or shortly after infusion of CAMPTOSAR. In the clinical
studies testing the every 3-week-dosage schedule, the median time to the onset of
late diarrhea was 5 days after irinotecan infusion. In the clinical studies evaluating
the weekly dosage schedule, the median time to onset of late diarrhea was 11 days
following administration of CAMPTOSAR. For patients starting treatment at the 125-mg/m2
weekly dose, the median duration of any grade of late diarrhea was 3 days. Among
those patients treated at the 125-mg/m2 weekly dose who
experienced grade 3 or 4 late diarrhea, the median duration of the entire episode
of diarrhea was 7 days. The frequency of grade 3 or 4 late diarrhea was somewhat
greater in patients starting treatment at 125 mg/m2 than
in patients given a 100-mg/m2 weekly starting dose (34%
[65/193] versus 23% [24/102]; p=0.08). The frequency of grade 3 and 4 late diarrhea
by age was significantly greater in patients ≥65 years than in patients <65 years
(40% [53/133] versus 23% [40/171]; p=0.002). In one study of the weekly dosage treatment,
the frequency of grade 3 and 4 late diarrhea was significantly greater in male than
in female patients (43% [25/58] versus 16% [5/32]; p=0.01), but there were no gender
differences in the frequency of grade 3 and 4 late diarrhea in the other two studies
of the weekly dosage treatment schedule. Colonic ulceration, sometimes with gastrointestinal
bleeding, has been observed in association with administration of CAMPTOSAR.
Hematology: CAMPTOSAR commonly causes neutropenia, leukopenia (including
lymphocytopenia), and anemia. Serious thrombocytopenia is uncommon. When evaluated
in the trials of weekly administration, the frequency of grade 3 and 4 neutropenia
was significantly higher in patients who received previous pelvic/abdominal irradiation
than in those who had not received such irradiation (48% [13/27] versus 24% [67/277];
p=0.04). In these same studies, patients with baseline serum total bilirubin levels
of 1.0 mg/dL or more also had a significantly greater likelihood of experiencing
first-cycle grade 3 or 4 neutropenia than those with bilirubin levels that were
less than 1.0 mg/dL (50% [19/38] versus 18% [47/266]; p<0.001). There were no
significant differences in the frequency of grade 3 and 4 neutropenia by age or
gender. In the clinical studies evaluating the weekly dosage schedule, neutropenic
fever (concurrent NCI grade 4 neutropenia and fever of grade 2 or greater) occurred
in 3% of the patients; 6% of patients received G-CSF for the treatment of neutropenia.
NCI grade 3 or 4 anemia was noted in 7% of the patients receiving weekly treatment;
blood transfusions were given to 10% of the patients in these trials.
Body as a Whole: Asthenia, fever, and abdominal pain are generally the most
common events of this type.
Cholinergic Symptoms: Patients may have cholinergic symptoms of rhinitis,
increased salivation, miosis, lacrimation, diaphoresis, flushing, and intestinal
hyperperistalsis that can cause abdominal cramping and early diarrhea. If these
symptoms occur, they manifest during or shortly after drug infusion. They are thought
to be related to the anticholinesterase activity of the irinotecan parent compound
and are expected to occur more frequently with higher irinotecan doses.
Hepatic: In the clinical studies evaluating the weekly dosage schedule, NCI
grade 3 or 4 liver enzyme abnormalities were observed in fewer than 10% of patients.
These events typically occur in patients with known hepatic metastases.
Dermatologic: Alopecia has been reported during treatment with CAMPTOSAR.
Rashes have also been reported but did not result in discontinuation of treatment.
Respiratory: Severe pulmonary events are infrequent. In the clinical studies
evaluating the weekly dosage schedule, NCI grade 3 or 4 dyspnea was reported in
4% of patients. Over half the patients with dyspnea had lung metastases; the extent
to which malignant pulmonary involvement or other preexisting lung disease may have
contributed to dyspnea in these patients is unknown.
Interstitial pulmonary disease presenting as pulmonary infiltrates is uncommon during
irinotecan therapy. Interstitial pulmonary disease can be fatal. Risk factors possibly
associated with the development of interstitial pulmonary disease include pre-existing
lung disease, use of pneumotoxic drugs, radiation therapy, and colony stimulating
factors. Patients with risk factors should be closely monitored for respiratory
symptoms before and during irinotecan therapy.
Neurologic: Insomnia and dizziness can occur, but are not usually considered
to be directly related to the administration of CAMPTOSAR. Dizziness may sometimes
represent symptomatic evidence of orthostatic hypotension in patients with dehydration.
Cardiovascular: Vasodilation (flushing) may occur during administration of
CAMPTOSAR. Bradycardia may also occur, but has not required intervention. These
effects have been attributed to the cholinergic syndrome sometimes observed during
or shortly after infusion of CAMPTOSAR. Thromboembolic events have been observed
in patients receiving CAMPTOSAR; the specific cause of these events has not been
determined.
Other Non-U.S. Clinical Trials
Irinotecan has been studied in over 1100 patients in Japan. Patients in these studies
had a variety of tumor types, including cancer of the colon or rectum, and were
treated with several different doses and schedules. In general, the types of toxicities
observed were similar to those seen in U.S. trials with CAMPTOSAR. There is some
information from Japanese trials that patients with considerable ascites or pleural
effusions were at increased risk for neutropenia or diarrhea. A potentially life-threatening
pulmonary syndrome, consisting of dyspnea, fever, and a reticulonodular pattern
on chest x-ray, was observed in a small percentage of patients in early Japanese
studies. The contribution of irinotecan to these preliminary events was difficult
to assess because these patients also had lung tumors and some had preexisting nonmalignant
pulmonary disease. As a result of these observations, however, clinical studies
in the United States have enrolled few patients with compromised pulmonary function,
significant ascites, or pleural effusions.
Post-Marketing Experience
The following events have been identified during postmarketing use of CAMPTOSAR
in clinical practice. Myocardial ischemic events have been observed following irinotecan
therapy predominantly in patients with underlying cardiac disease, other known risk
factors for cardiac disease or previous cytotoxic chemotherapy (See also Table 7,
thromboembolic events). Infrequent cases of ulcerative and ischemic colitis have
been observed. This can be complicated by ulceration, bleeding, ileus, obstruction,
and infection, including typhlitis. Patients experiencing ileus should receive prompt
antibiotic support (see PRECAUTIONS). Rare cases of megacolon and intestinal perforation
have been reported. Rare cases of symptomatic pancreatitis or asymptomatic elevated
pancreatic enzymes have been observed.
Hypersensitivity reactions including severe anaphylactic or anaphylactoid reactions
have also been observed (see WARNINGS).
Rare cases of hyponatremia mostly related with diarrhea and vomiting have been reported.
Increases in serum levels of transaminases (i.e., AST and ALT) in the absence of
progressive liver metastasis; transient increase of amylase and occasionally transient
increase of lipase have been very rarely reported.
Infrequent cases of renal insufficiency including acute renal failure, hypotension
or circulatory failure have been observed in patients who experienced episodes of
dehydration associated with diarrhea and/or vomiting, or sepsis (see WARNINGS).
Early effects such as muscular contraction or cramps and paresthesia have been reported.
Hiccups have been reported.