CLINICAL PHARMACOLOGY
Mechanism Of Action
Bevacizumab products bind VEGF
and prevent the interaction of VEGF to its receptors (Flt-1 and KDR) on the
surface of endothelial cells. The interaction of VEGF with its receptors leads
to endothelial cell proliferation and new blood vessel formation in in vitro
models of angiogenesis. Administration of bevacizumab products to
xenotransplant models of colon cancer in nude (athymic) mice caused reduction
of microvascular growth and inhibition of metastatic disease progression.
Pharmacokinetics
The pharmacokinetic profile of
bevacizumab was assessed using an assay that measures total serum bevacizumab
concentrations (i.e., the assay did not distinguish between free bevacizumab
and bevacizumab bound to VEGF ligand). Based on a population pharmacokinetic
analysis of 491 patients who received 1 to 20 mg/kg of bevacizumab every week,
every 2 weeks, or every 3 weeks, bevacizumab pharmacokinetics are linear and
the predicted time to reach more than 90% of steady state concentration is 84
days. The accumulation ratio following a dose of 10 mg/kg of bevacizumab once
every 2 weeks is 2.8.
Population simulations of bevacizumab exposures provide a
median trough concentration of 80.3 mcg/mL on Day 84 (10th, 90th percentile:
45, 128) following a dose of 5 mg/kg once every two weeks.
Distribution
The mean (% coefficient of
variation [CV%]) central volume of distribution is 2.9 (22%) L.
Elimination
The mean (CV%) clearance is
0.23 (33) L/day. The estimated half-life is 20 days (11 to 50 days).
Specific Populations
The clearance of bevacizumab
varied by body weight, sex, and tumor burden. After correcting for body weight,
males had a higher bevacizumab clearance (0.26 L/day vs. 0.21 L/day) and a
larger central volume of distribution (3.2 L vs. 2.7 L) than females. Patients
with higher tumor burden (at or above median value of tumor surface area) had a
higher bevacizumab clearance (0.25 L/day vs. 0.20 L/day) than patients with
tumor burdens below the median. In Study AVF2107g, there was no evidence
of lesser efficacy (hazard ratio for overall survival) in males or patients
with higher tumor burden treated with bevacizumab as compared to females and
patients with low tumor burden.
Animal Toxicology And/Or Pharmacology
Rabbits dosed with bevacizumab exhibited reduced wound
healing capacity. Using full-thickness skin incision and partial thickness
circular dermal wound models, bevacizumab dosing resulted in reductions in
wound tensile strength, decreased granulation and re-epithelialization, and
delayed time to wound closure.
Clinical Studies
Metastatic Colorectal Cancer
Study AVF2107g
The safety and efficacy of bevacizumab was evaluated in a
double-blind, active-controlled study [AVF2107g (NCT00109070)] in 923 patients
with previously untreated mCRC who were randomized (1:1:1) to placebo with
bolus-IFL (irinotecan 125 mg/m², fluorouracil 500 mg/m², and leucovorin 20 mg/m²
given once weekly for 4 weeks every 6 weeks), bevacizumab (5 mg/kg every 2
weeks) with bolus-IFL, or bevacizumab (5 mg/kg every 2 weeks) with fluorouracil
and leucovorin. Enrollment to the bevacizumab with fluorouracil and leucovorin
arm was discontinued, after enrollment of 110 patients in accordance with the
protocol-specified adaptive design. Bevacizumab was continued until disease
progression or unacceptable toxicity or for a maximum of 96 weeks. The main
outcome measure was overall survival (OS).
The median age was 60 years; 60% were male, 79% were
White, 57% had an ECOG performance status of 0, 21% had a rectal primary and
28% received prior adjuvant chemotherapy. The dominant site of disease was
extra-abdominal in 56% of patients and was the liver in 38% of patients.
The addition of bevacizumab improved survival across
subgroups defined by age (< 65 years, ≥ 65 years) and sex. Results are
presented in Table 5 and Figure 1.
Table 5: Efficacy Results in Study AVF2107g
Efficacy Parameter |
Bevacizumab with bolus-IFL
(N=402) |
Placebo with bolus-IFL
(N=411) |
Overall Survival |
Median, in months |
20.3 |
15.6 |
Hazard ratio (95% CI) |
0.66 (0.54, 0.81) |
p-valuea |
<0.001 |
Progression-Free Survival |
Median, in months |
10.6 |
6.2 |
Hazard ratio (95% CI) |
0.54 (0.45, 0.66) |
p-valuea |
< 0.001 |
Overall Response Rate |
Rate (%) |
45% |
35% |
p-valueb |
< 0.01 |
Duration of Response |
Median, in months |
10.4 |
7.1 |
a by stratified log-rank test.
b by χ2 test. |
Figure 1: Kaplan-Meier
Curves for Duration of Survival in Metastatic Colorectal Cancer in Study
AVF2107g
Among the 110 patients
randomized to bevacizumab with fluorouracil and leucovorin, median OS was 18.3
months, median progression-free survival (PFS) was 8.8 months, overall response
rate (ORR) was 39%, and median duration of response was 8.5 months.
Study E3200
The safety and efficacy of bevacizumab were evaluated in
a randomized, open-label, active-controlled study [E3200 (NCT00025337)] in 829
patients who were previously treated with irinotecan and fluorouracil for
initial therapy for metastatic disease or as adjuvant therapy. Patients were
randomized (1:1:1) to FOLFOX4 (Day 1: oxaliplatin 85 mg/m² and leucovorin 200
mg/m² concurrently, then fluorouracil 400 mg/m² bolus followed by 600 mg/m² continuously;
Day 2: leucovorin 200 mg/m², then fluorouracil 400 mg/m² bolus followed by 600
mg/m² continuously; every 2 weeks), bevacizumab (10 mg/kg every 2 weeks prior
to FOLFOX4 on Day 1) with FOLFOX4, or bevacizumab alone (10 mg/kg every 2
weeks). Bevacizumab was continued until disease progression or unacceptable
toxicity. The main outcome measure was OS.
The bevacizumab alone arm was closed to accrual after
enrollment of 244 of the planned 290 patients following a planned interim
analysis by the data monitoring committee based on evidence of decreased
survival compared to FOLFOX4 alone.
The median age was 61 years; 60% were male, 87% were
White, 49% had an ECOG performance status of 0, 26% received prior radiation
therapy, and 80% received prior adjuvant chemotherapy, 99% received prior
irinotecan with or without fluorouracil for metastatic disease, and 1% received
prior irinotecan and fluorouracil as adjuvant therapy.
The addition of bevacizumab to FOLFOX4 resulted in significantly
longer survival as compared to FOLFOX4 alone; median OS was 13.0 months vs.
10.8 months [hazard ratio (HR) 0.75 (95% CI: 0.63, 0.89), p-value of 0.001
stratified log-rank test] with clinical benefit seen in subgroups defined by
age (< 65 years, ≥ 65 years) and sex. PFS and ORR based on
investigator assessment were higher in patients receiving bevacizumab with
FOLFOX4.
Study TRC-0301
The activity of bevacizumab with fluorouracil (as bolus
or infusion) and leucovorin was evaluated in a single arm study [TRC-0301
(NCT00066846)] enrolling 339 patients with mCRC with disease progression
following both irinotecan- and oxaliplatin-based chemotherapy. Seventy-three
percent of patients received concurrent bolus fluorouracil and leucovorin. One
objective partial response was verified in the first 100 evaluable patients for
an ORR of 1% (95% CI: 0%, 5.5%).
Study ML18147
The safety and efficacy of bevacizumab were evaluated in
a prospective, randomized, open-label, multinational, controlled study [ML18147
(NCT00700102)] in 820 patients with histologically confirmed mCRC who had
progressed on a first-line bevacizumab-containing regimen. Patients were
excluded if they progressed within 3 months of initiating first-line
chemotherapy and if they received bevacizumab for less than 3 consecutive
months in the first-line setting. Patients were randomized (1:1) within 3
months after discontinuing bevacizumab as first-line treatment to receive
fluoropyrimidine-irinotecan- or fluoropyrimidine-oxaliplatinbased chemotherapy
with or without bevacizumab (5 mg/kg every 2 weeks or 7.5 mg/kg every 3 weeks).
The choice of second-line treatment was contingent upon first-line
chemotherapy. Second-line treatment was administered until progressive disease
or unacceptable toxicity. The main outcome measure was OS. A secondary outcome
measure was ORR.
The median age was 63 years (21 to 84 years); 64% were
male, 52% had an ECOG performance status of 1, 44% had an ECOG performance
status of 0, 58% received irinotecan-based therapy as first-line treatment, 55%
progressed on first-line treatment within 9 months, and 77% received their last
dose of bevacizumab as first-line treatment within 42 days of being randomized.
Second-line chemotherapy regimens were generally balanced between each arm.
The addition of bevacizumab to fluoropyrimidine-based
chemotherapy resulted in a statistically significant prolongation of OS and
PFS. There was no significant difference in ORR. Results are presented in Table
6 and Figure 2.
Table 6: Efficacy Results in Study ML18147
Efficacy Parameter |
Bevacizumab with Chemotherapy
(N=409) |
Chemotherapy
(N=411) |
Overall Survivala |
Median, in months |
11.2 |
9.8 |
Hazard ratio (95% CI) |
0.81 (0.69, 0.94) |
Progression-Free Survivalb |
Median, in months |
5.7 |
4.0 |
Hazard ratio (95% CI) |
0.68 (0.59, 0.78) |
a p = 0.0057 by unstratified log-rank test.
b p-value < 0.0001 by unstratified log-rank test. |
Figure 2: Kaplan-Meier
Curves for Duration of Survival in Metastatic Colorectal Cancer in Study
ML18147
Lack Of Efficacy In Adjuvant
Treatment Of Colon Cancer
Lack of efficacy of bevacizumab
as an adjunct to standard chemotherapy for the adjuvant treatment of colon
cancer was determined in two randomized, open-label, multicenter clinical
studies.
The first study [BO17920
(NCT00112918)] was conducted in 3451 patients with high-risk stage II and III
colon cancer, who had undergone surgery for colon cancer with curative intent.
Patients were randomized to receive bevacizumab at a dose equivalent to 2.5
mg/kg/week on either a 2-weekly schedule with FOLFOX4 (N=1155), or on a
3-weekly schedule with XELOX (N=1145) or FOLFOX4 alone (N=1151). The main
outcome measure was disease free survival (DFS) in patients with stage III
colon cancer.
The median age was 58 years;
54% were male, 84% were White and 29% were ≥ 65 years. Eighty-three
percent had stage III disease.
The addition of bevacizumab to
chemotherapy did not improve DFS. As compared to FOLFOX4 alone, the proportion
of stage III patients with disease recurrence or with death due to disease
progression were numerically higher for patients receiving bevacizumab with
FOLFOX4 or with XELOX. The hazard ratios for DFS were 1.17 (95% CI:
0.98, 1.39) for bevacizumab with FOLFOX4 versus FOLFOX4 alone and 1.07 (95% CI:
0.90, 1.28) for bevacizumab with XELOX versus FOLFOX4 alone. The hazard ratios
for OS were 1.31 (95% CI: 1.03, 1.67) and 1.27 (95% CI: 1, 1.62) for the
comparison of bevacizumab with FOLFOX4 versus FOLFOX4 alone and bevacizumab
with XELOX versus FOLFOX4 alone, respectively. Similar lack of efficacy for DFS
was observed in the bevacizumab-containing arms compared to FOLFOX4 alone in
the high-risk stage II cohort.
In a second study [NSABP-C-08 (NCT00096278)], patients
with stage II and III colon cancer who had undergone surgery with curative
intent, were randomized to receive either bevacizumab administered at a dose
equivalent to 2.5 mg/kg/week with mFOLFOX6 (N=1354) or mFOLFOX6 alone (N=1356).
The median age was 57 years, 50% were male and 87% White. Seventy-five percent
had stage III disease. The main outcome was DFS among stage III patients. The
HR for DFS was 0.92 (95% CI: 0.77, 1.10). OS was not significantly improved
with the addition of bevacizumab to mFOLFOX6 [HR 0.96 (95% CI: 0.75, 1.22)].
First-Line Non–Squamous Non–Small Cell Lung Cancer
(NSCLC)
Study E4599
The safety and efficacy of bevacizumab as first-line
treatment of patients with locally advanced, metastatic, or recurrent
non-squamous NSCLC was studied in a single, large, randomized,
active-controlled, open-label, multicenter study [E4599 (NCT00021060)]. A total
of 878 chemotherapy-naïve patients with locally advanced, metastatic or
recurrent non–squamous NSCLC were randomized (1:1) to receive six 21-day cycles
of paclitaxel (200 mg/m²) and carboplatin (AUC 6) with or without
bevacizumab 15 mg/kg. After completing or discontinuing chemotherapy, patients
randomized to receive bevacizumab continued to receive bevacizumab alone until
disease progression or until unacceptable toxicity. The trial excluded patients
with predominant squamous histology (mixed cell type tumors only), CNS
metastasis, gross hemoptysis (½ teaspoon or more of red blood), unstable
angina, or receiving therapeutic anticoagulation. The main outcome measure was
duration of survival.
The median age was 63 years; 54% were male, 43% were ≥
65 years, and 28% had ≥ 5% weight loss at study entry. Eleven percent had
recurrent disease. Of the 89% with newly diagnosed NSCLC, 12% had Stage IIIB
with malignant pleural effusion and 76% had Stage IV disease.
OS was statistically significantly longer for patients
receiving bevacizumab with paclitaxel and carboplatin compared with those
receiving chemotherapy alone. Median OS was 12.3 months vs. 10.3 months [HR
0.80 (95% CI: 0.68, 0.94), final p-value of 0.013, stratified log-rank test].
Based on investigator assessment which was not independently verified, patients
were reported to have longer PFS with bevacizumab with paclitaxel and
carboplatin compared to chemotherapy alone. Results are presented in Figure 3.
Figure 3: Kaplan-Meier Curves for Duration of Survival
in First-Line Non-Squamous Non-Small Cell Lung Cancer in Study E4599
In an exploratory analysis
across patient subgroups, the impact of bevacizumab on OS was less robust in
the following subgroups: women [HR 0.99 (95% CI: 0.79, 1.25)], patients ≥
65 years [HR 0.91 (95% CI: 0.72, 1.14)] and patients with ≥ 5% weight
loss at study entry [HR 0.96 (95% CI: 0.73, 1.26)].
Study BO17704
The safety and efficacy of
bevacizumab in patients with locally advanced, metastatic or recurrent
non-squamous NSCLC, who had not received prior chemotherapy was studied in
another randomized, double-blind, placebo-controlled study [BO17704
(NCT00806923)]. A total of 1043 patients were randomized (1:1:1) to receive
cisplatin and gemcitabine with placebo, bevacizumab 7.5 mg/kg or bevacizumab 15
mg/kg. The main outcome measure was PFS. Secondary outcome measure was OS.
The median age was 58 years;
36% were female and 29% were ≥ 65 years. Eight percent had recurrent
disease and 77% had Stage IV disease.
PFS was significantly higher in
both bevacizumab-containing arms compared to the placebo arm [HR 0.75 (95% CI:
0.62, 0.91), p-value of 0.0026 for bevacizumab 7.5 mg/kg and HR 0.82 (95% CI:
0.68, 0.98), p-value of 0.0301 for bevacizumab 15 mg/kg]. The addition of
bevacizumab to cisplatin and gemcitabine failed to demonstrate an improvement
in the duration of OS [HR 0.93 (95% CI: 0.78, 1.11), p-value of 0.420 for
bevacizumab 7.5 mg/kg and HR 1.03 (95% CI: 0.86, 1.23), p-value of 0.761 for
bevacizumab 15 mg/kg].
Recurrent Glioblastoma
Study EORTC 26101
The safety and efficacy of bevacizumab were evaluated in
a multicenter, randomized (2:1), open-label study in patients with recurrent
GBM (EORTC 26101, NCT01290939). Patients with first progression following
radiotherapy and temozolomide were randomized (2:1) to receive bevacizumab (10
mg/kg every 2 weeks) with lomustine (90 mg/m² every 6 weeks) or lomustine (110
mg/m² every 6 weeks) alone until disease progression or unacceptable toxicity.
Randomization was stratified by World Health Organization performance status (0
vs. > 0), steroid use (yes vs. no), largest tumor diameter (≤ 40 vs.
> 40 mm), and institution. The main outcome measure was OS. Secondary
outcome measures were investigator-assessed PFS and ORR per the modified
Response Assessment in Neuro-oncology (RANO) criteria, health related quality
of life (HRQoL), cognitive function, and corticosteroid use.
A total of 432 patients were randomized to receive
lomustine alone (N=149) or bevacizumab with lomustine (N=283). The median age
was 57 years; 24.8% of patients were ≥ 65 years. The majority of patients
with were male (61%); 66% had a WHO performance status score ≥ 0; and in
56% the largest tumor diameter was ≤ 40 mm. Approximately 33% of patients
randomized to receive lomustine received bevacizumab following documented
progression.
No difference in OS (HR 0.91, p-value of 0.4578) was
observed between arms; therefore, all secondary outcome measures are
descriptive only. PFS was longer in the bevacizumab with lomustine arm [HR 0.52
(95% CI: 0.41, 0.64)] with a median PFS of 4.2 months in the bevacizumab with
lomustine arm and 1.5 months in the lomustine arm. Among the 50% of patients
receiving corticosteroids at the time of randomization, a higher percentage of
patients in the bevacizumab with lomustine arm discontinued corticosteroids
(23% vs. 12%).
Study AVF3708g And Study NCI 06-C-0064E
The efficacy and safety of bevacizumab 10 mg/kg every 2
weeks in patients with previously treated GBM were evaluated in one single arm
single center study (NCI 06-C-0064E) and a randomized noncomparative
multicenter study [AVF3708g(NCT00345163)]. Response rates in both studies were evaluated
based on modified WHO criteria that considered corticosteroid use. In AVF3708g,
the response rate was 25.9% (95% CI: 17%, 36.1%) with a median duration of
response of 4.2 months (95% CI: 3, 5.7). In Study NCI 06-C-0064E, the response
rate was 19.6% (95% CI: 10.9%, 31.3%) with a median duration of response of 3.9
months (95% CI: 2.4, 17.4).
Metastatic Renal Cell Carcinoma
Study BO17705
The safety and efficacy of bevacizumab were evaluated in
patients with treatment-naïve mRCC in a multicenter, randomized, double-blind,
international study [BO17705 (NCT00738530)] comparing interferon alfa and
bevacizumab versus interferon alfa and placebo. A total of 649 patients who had
undergone a nephrectomy were randomized (1:1) to receive either bevacizumab (10
mg/kg every 2 weeks; N=327) or placebo (every 2 weeks; N=322) with interferon
alfa (9 MIU subcutaneously three times weekly for a maximum of 52 weeks).
Patients were treated until disease progression or unacceptable toxicity. The
main outcome measure was investigator-assessed PFS. Secondary outcome measures
were ORR and OS.
The median age was 60 years (18 to 82 years); 70% were
male and 96% were White. The study population was characterized by Motzer
scores as follows: 28% favorable (0), 56% intermediate (1-2), 8% poor (3-5),
and 7% missing.
PFS was statistically significantly prolonged among
patients receiving bevacizumab compared to placebo; median PFS was 10.2 months
vs. 5.4 months [HR 0.60 (95% CI: 0.49, 0.72), p-value < 0.0001, stratified
log-rank test]. Among the 595 patients with measurable disease, ORR was also
significantly higher (30% vs. 12%, p-value < 0.0001, stratified CMH test).
There was no improvement in OS based on the final analysis conducted after 444
deaths, with a median OS of 23 months in the patients receiving bevacizumab
with interferon alfa and 21 months in patients receiving interferon alone [HR
0.86, (95% CI: 0.72, 1.04)]. Results are presented in Figure 4.
Figure 4: Kaplan-Meier Curves for Progression-Free
Survival in Metastatic Renal Cell Carcinoma in Study BO17705
Persistent, Recurrent, Or Metastatic
Cervical Cancer
Study GOG-0240
The safety and efficacy of
bevacizumab were evaluated in patients with persistent, recurrent, or
metastatic cervical cancer in a randomized, four-arm, multicenter study
comparing bevacizumab with chemotherapy versus chemotherapy alone [GOG-0240
(NCT00803062)]. A total of 452 patients were randomized (1:1:1:1) to receive
paclitaxel and cisplatin with or without bevacizumab, or paclitaxel and
topotecan with or without bevacizumab.
The dosing regimens for
bevacizumab, paclitaxel, cisplatin and topotecan were as follows:
- Day 1: Paclitaxel 135 mg/m² over 24 hours, Day 2:
cisplatin 50 mg/m² with bevacizumab;
- Day 1: Paclitaxel 175 mg/m² over 3 hours, Day 2:
cisplatin 50 mg/m² with bevacizumab;
- Day 1: Paclitaxel 175 mg/m² over 3 hours with cisplatin
50 mg/m² with bevacizumab;
- Day 1: Paclitaxel 175 mg/m² over 3 hours with
bevacizumab, Days 1-3: topotecan IV 0.75 mg/m² over 30 minutes.
Patients were treated until
disease progression or unacceptable adverse reactions. The main outcome measure
was OS. Secondary outcome measures included ORR.
The median age was 48 years (20
to 85 years). Of the 452 patients randomized at baseline, 78% of patients were
White, 80% had received prior radiation, 74% had received prior chemotherapy
concurrent with radiation, and 32% had a platinum-free interval of less than 6
months. Patients had a GOG performance status of 0 (58%) or 1 (42%).
Demographic and disease characteristics were balanced across arms.
Results are presented in Figure
5 and Table 7.
Figure 5: Kaplan-Meier Curves for Overall Survival in
Persistent, Recurrent, or Metastatic Cervical Cancer in Study GOG-0240
Table 7: Efficacy Results in
Study GOG-0240
Efficacy Parameter |
Bevacizumab with Chemotherapy
(N=227) |
Chemotherapy
(N=225) |
Overall Survival |
Median, in monthsa |
16.8 |
12.9 |
Hazard ratio (95% CI) |
0.74 (0.58; 0.94) |
p-value b |
0.0132 |
a Kaplan-Meier estimates.
b log-rank test (stratified). |
The ORR was higher in patients
who received bevacizumab with chemotherapy [45% (95% CI: 39, 52)] compared to
patients who received chemotherapy alone [34% (95% CI: 28, 40)].
Table 8: Efficacy Results in Study GOG-0240
Efficacy Parameter |
Topotecan and Paclitaxel with or without Bevacizumab
(N=223) |
Cisplatin and Paclitaxel with or without Bevacizumab
(N=229) |
Overall Survival |
Median, in monthsa |
13.3 |
15.5 |
Hazard ratio (95% CI) |
1.15 (0.91, 1.46) |
p-value |
0.23 |
a Kaplan-Meier estimates. |
The HR for OS with bevacizumab
with cisplatin and paclitaxel as compared to cisplatin and paclitaxel alone was
0.72 (95% CI: 0.51, 1.02). The HR for OS with bevacizumab with topotecan and
paclitaxel as compared to topotecan and paclitaxel alone was 0.76 (95% CI:
0.55, 1.06).