| VECTIBIX BENEFITS AND SIDE EFFECTS |
The Food and Drug Administration (FDA) approved Amgen's Vectibix
(panitumumab; formerly known as ABX-EGF) for the treatment of
patients with colorectal cancer that has metastasized (spread to
other parts of the body) following standard chemotherapy. Vectibix,
a monoclonal antibody that binds to a protein called epidermal
growth factor receptor or EGFR on some cancer cells, received an
accelerated approval after showing effectiveness in slowing tumor
growth and, in some cases, reducing the size of the tumor. [4]
FDA approved Vectibix on the basis of the results of a randomized,
controlled clinical trial of 463 patients with metastatic cancer of the
colon and the rectum after undergoing treatment with chemotherapy
drugs, fluoropyrimidine, oxaliplatin and irinotecan. [4]
The mean time to disease progression or death in patients receiving
Vectibix was 96 days versus 60 days in patients receiving the best
standard supportive care. In addition, 8 percent of the patients on
Vectibix experienced a tumor shrinkage that in some cases exceeded
50 percent of the pre-treatment size of the tumor. Both study groups
showed similar overall survival. [4]
SIDE EFFECTS OF VECTIBIX
The most serious adverse events in the studies of Vectibix included
pulmonary fibrosis, severe skin rash complicated by infections,
infusion reactions, abdominal pain, nausea, vomiting and
constipation. The most common adverse side effects of Vectibix
associated with the drug included skin rash, fatigue, abdominal pain,
nausea, and diarrhea. [4]
First- and second-line therapy of metastatic colorectal cancer
In the United States, it is estimated that 150,000 new cases of colon
cancer will be diagnosed and 55,000 deaths will occur from colon and
rectal cancer in 2006. Approximately 70 percent of all colorectal
carcinomas test positive for EGFR. Colorectal cancer is the third most
common cancer and the third leading cause of cancer mortality in the
United States. [4]
After years of stagnation, the treatment of metastatic colorectal
cancer has recently made dramatic advances. The previous standard
of care, 5-fluorouracil, becomes the backbone of combination
regimens with oxaliplatin or irinotecan. The addition of biological
agents, such as the vascular endothelial growth factor inhibitor,
bevacizumab, and the epidermal growth factor receptor inhibitors,
cetuximab and panitumumab, have further enhanced the activity of
conventional chemotherapy. These advances have increased the
overall survival of advanced colorectal cancer patients, which was
once 6 months with best supportive care, to over 2 years if all active
agents are used in the course of the disease. [3]
Role of Panitumumab in the management of metastatic colorectal
cancer.
Panitumumab has proven to be very well tolerated alone and in
combination with other cytotoxic chemotherapeutic agents.
Panitumumab has demonstrated efficacy as monotherapy and with
standard chemotherapeutic agents in a wide variety of cancer types,
including non-small-cell lung cancer, renal, and colorectal cancer. The
only significant toxicity or side effect has been a rash similar to that
seen with other agents targeting the epidermal growth factor
receptor, and such reactions have been predominantly mild to
moderate. [1]
In metastatic colorectal cancer, panitumumab has been safe and
efficacious when given with other commonly used agents in this
disease, including irinotecan and fluorouracil. Current studies under
way are looking at panitumumab in combination with FOLFOX
(fluorouracil/leucovorin/oxaliplatin) plus bevacizumab as well as with
novel agents that have yet to come into common clinical practice. [1]
Phase III Trial Results
The results of a phase III trial which compared panitumumab as a
single agent to best supportive care in patients with previously
treated metastatic colorectal cancer have recently been reported
Pantitumumab therapy resulted in a 46% reduction in the risk of
tumor progression and a partial response rate of 8%. The side effect
- rash was reported in 90% of patients with increased severity
significantly correlated with improved medium overall survival (OS).
[2]
About Amgen
Amgen has a market capitalization of about $79.77 billion and a
range of drugs aimed at treating cancer and anemia. It is the cancer
franchise that caught a boost with the approval of Vectibix in
September of 2006. Vectibix is shaping up to be a key competitor
with Imclone Systems Inc's Erbitux. Both drugs are aimed to treat
colon cancer. [5]
REFERENCE:
[1] Saif MW and Cohenuram M, Yale University School of Medicine, Role of
panitumumab in the management of metastatic colorectal cancer. Clin
Colorectal Cancer. 2006 Jul;6(2):118-24. [2] Gibson TB, et al, CIG Medical
Group, Randomized phase III trial results of panitumumab, a fully human
anti-epidermal growth factor receptor monoclonal antibody, in metastatic
colorectal cancer. Clin Colorectal Cancer. 2006 May;6(1):29-31. [3] Terstriep
S et al, Mayo Clinic College of Medicine, First- and second-line therapy of
metastatic colorectal cancer. Expert Rev Anticancer Ther. 2006
Jun;6(6):921-30. [4] FDA Approves a New Drug for Colorectal Cancer,
Vectibix FDA News September 27, 2006. [5] The Year in Review: Amgen's
Good News AP December 27 2006
(panitumumab; formerly known as ABX-EGF) for the treatment of
patients with colorectal cancer that has metastasized (spread to
other parts of the body) following standard chemotherapy. Vectibix,
a monoclonal antibody that binds to a protein called epidermal
growth factor receptor or EGFR on some cancer cells, received an
accelerated approval after showing effectiveness in slowing tumor
growth and, in some cases, reducing the size of the tumor. [4]
FDA approved Vectibix on the basis of the results of a randomized,
controlled clinical trial of 463 patients with metastatic cancer of the
colon and the rectum after undergoing treatment with chemotherapy
drugs, fluoropyrimidine, oxaliplatin and irinotecan. [4]
The mean time to disease progression or death in patients receiving
Vectibix was 96 days versus 60 days in patients receiving the best
standard supportive care. In addition, 8 percent of the patients on
Vectibix experienced a tumor shrinkage that in some cases exceeded
50 percent of the pre-treatment size of the tumor. Both study groups
showed similar overall survival. [4]
SIDE EFFECTS OF VECTIBIX
The most serious adverse events in the studies of Vectibix included
pulmonary fibrosis, severe skin rash complicated by infections,
infusion reactions, abdominal pain, nausea, vomiting and
constipation. The most common adverse side effects of Vectibix
associated with the drug included skin rash, fatigue, abdominal pain,
nausea, and diarrhea. [4]
First- and second-line therapy of metastatic colorectal cancer
In the United States, it is estimated that 150,000 new cases of colon
cancer will be diagnosed and 55,000 deaths will occur from colon and
rectal cancer in 2006. Approximately 70 percent of all colorectal
carcinomas test positive for EGFR. Colorectal cancer is the third most
common cancer and the third leading cause of cancer mortality in the
United States. [4]
After years of stagnation, the treatment of metastatic colorectal
cancer has recently made dramatic advances. The previous standard
of care, 5-fluorouracil, becomes the backbone of combination
regimens with oxaliplatin or irinotecan. The addition of biological
agents, such as the vascular endothelial growth factor inhibitor,
bevacizumab, and the epidermal growth factor receptor inhibitors,
cetuximab and panitumumab, have further enhanced the activity of
conventional chemotherapy. These advances have increased the
overall survival of advanced colorectal cancer patients, which was
once 6 months with best supportive care, to over 2 years if all active
agents are used in the course of the disease. [3]
Role of Panitumumab in the management of metastatic colorectal
cancer.
Panitumumab has proven to be very well tolerated alone and in
combination with other cytotoxic chemotherapeutic agents.
Panitumumab has demonstrated efficacy as monotherapy and with
standard chemotherapeutic agents in a wide variety of cancer types,
including non-small-cell lung cancer, renal, and colorectal cancer. The
only significant toxicity or side effect has been a rash similar to that
seen with other agents targeting the epidermal growth factor
receptor, and such reactions have been predominantly mild to
moderate. [1]
In metastatic colorectal cancer, panitumumab has been safe and
efficacious when given with other commonly used agents in this
disease, including irinotecan and fluorouracil. Current studies under
way are looking at panitumumab in combination with FOLFOX
(fluorouracil/leucovorin/oxaliplatin) plus bevacizumab as well as with
novel agents that have yet to come into common clinical practice. [1]
Phase III Trial Results
The results of a phase III trial which compared panitumumab as a
single agent to best supportive care in patients with previously
treated metastatic colorectal cancer have recently been reported
Pantitumumab therapy resulted in a 46% reduction in the risk of
tumor progression and a partial response rate of 8%. The side effect
- rash was reported in 90% of patients with increased severity
significantly correlated with improved medium overall survival (OS).
[2]
About Amgen
Amgen has a market capitalization of about $79.77 billion and a
range of drugs aimed at treating cancer and anemia. It is the cancer
franchise that caught a boost with the approval of Vectibix in
September of 2006. Vectibix is shaping up to be a key competitor
with Imclone Systems Inc's Erbitux. Both drugs are aimed to treat
colon cancer. [5]
REFERENCE:
[1] Saif MW and Cohenuram M, Yale University School of Medicine, Role of
panitumumab in the management of metastatic colorectal cancer. Clin
Colorectal Cancer. 2006 Jul;6(2):118-24. [2] Gibson TB, et al, CIG Medical
Group, Randomized phase III trial results of panitumumab, a fully human
anti-epidermal growth factor receptor monoclonal antibody, in metastatic
colorectal cancer. Clin Colorectal Cancer. 2006 May;6(1):29-31. [3] Terstriep
S et al, Mayo Clinic College of Medicine, First- and second-line therapy of
metastatic colorectal cancer. Expert Rev Anticancer Ther. 2006
Jun;6(6):921-30. [4] FDA Approves a New Drug for Colorectal Cancer,
Vectibix FDA News September 27, 2006. [5] The Year in Review: Amgen's
Good News AP December 27 2006
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