|
News and Noteworthy
By
Amy D’Orazio, PhD
Colorectal Cancer >
Avastin Combinations Add Up
Colorectal cancer therapy received a major boost at this year’s
American Society of Clinical Oncology (ASCO) meeting, with the reporting
of a trial showing that AvastinTM (bevacizumab)
significantly prolonged the survival of patients with advanced colorectal
cancer when given in combination with chemotherapy. This drug, which
has been given fast-track status by the FDA, could receive FDA approval
as soon as the end of this year and has the capability to transform
the treatment of colorectal cancer.
Avastin, an antibody that decreases the blood supply to tumors,
inhibits the effects of a protein secreted by many types of tumor
cells known as vascular endothelial cell growth factor (VEGF). Tumors
secrete VEGF to promote the growth of new blood vessels that will
carry nutrients and oxygen the tumor needs to survive. Researchers
have long believed that shutting down a tumor’s blood supply
would help in the eradication of the tumor, because tumors, like
normal tissues, need nutrients and oxygen from blood to survive.
Many such drugs have been developed, but until now, none has been
able to significantly impact the treatment of a tumor type. When
used alone, Avastin has shown the ability to reduce the growth of
a number of tumor types, including breast, lung, and colorectal
cancers.
Findings from a large phase III trial, which compared treatment
with chemotherapy (irinotecan, 5-FU, and leucovorin) alone to chemotherapy
plus Avastin, were highly encouraging. Advanced colorectal cancer
patients given Avastin plus chemotherapy experienced prolonged survival
and more showed signs of regression of their colon cancer.
More than 800 patients were enrolled in the trial. Overall response
improved from 35% in patients given chemotherapy alone to 45% in
patients given Avastin plus chemotherapy. The addition of Avastin
also resulted in a 35% decrease in the risk of death compared to
patients who received only chemotherapy. Overall, patients given
Avastin survived a median of about five months longer than the patients
given chemotherapy alone.
The main side effect with Avastin was high blood pressure, which
can be controlled by medication. There were no significant increases
in the risks of bleeding or blood clots with Avastin. Overall, Avastin
is a major advance for patients with advanced colorectal cancer.
To learn more about Avastin, or for a live webcast about this study,
visit www.avastin.com.
Brain Tumor >
Shutting Down the Signal
A new drug, Tarceva® (erlotinib), which has
shown activity in lung cancer, also appears to shrink or stabilize
a type of brain tumor known as malignant glioma, according to a
study presented at ASCO.
Tarceva blocks the epidermal growth factor receptor (EGFR). In brain
cancers, EGFR is often mutated, leading to a constant “on”
signal for growth of tumor cells. Tarceva targets this mutated protein
and shuts it down.
Sixteen percent of the patients who were given Tarceva alone or
in combination with temozolomide, a type of chemotherapy, showed
disease shrinkage. The main side effect was an acne-like rash. Two
studies are ongoing with Tarceva in brain cancers, one in patients
with newly diagnosed disease and one in patients who have relapsed
after a prior treatment.
Multiple Myeloma >
Cleaning Up on Cancer
Could lack of good housekeeping kill you? Maybe—if you’re
a cancer cell. Proteasomes are a complex of proteins within a cell
that degrade other proteins, giving them a measure of control over
cell division, cell growth, and cell death.
Researchers have found that a novel drug called Velcade™
(bortezomib) inhibits the proteasome, leading to the death of multiple
types of cancer. Cancer cells appear to be particularly vulnerable
to this type of drug, allowing specific targeting of the drug to
the cancer with normal cells remaining relatively untouched.
The promise of Velcade was first seen in multiple myeloma, a cancer
of the blood cells that generally affects the bone marrow. In more
than 200 multiple myeloma patients who relapsed after other treatments,
28% showed a response to Velcade. Based on this data, Velcade was
approved by the FDA for use in multiple myeloma patients in May
2003.
Velcade is now being studied for other types of cancers. At the
2003 ASCO meeting, encouraging activity was reported in patients
with lymphoma. In two separate studies with a total of 34 evaluable
patients, 16 had a complete or partial response, which was particularly
encouraging because many of these patients had already relapsed
from multiple treatments. Velcade also showed good activity among
patients who had aggressive forms of lymphoma such as mantle cell
lymphoma. Clinical activity was also seen in trials of Velcade in
lung and colon cancer patients. Other trials are ongoing in advanced
breast and ovarian cancer.
To learn more, visit www.velcade.com.
Nausea >
Blocking the Nausea Response
More than half of cancer patients undergoing chemotherapy will experience
vomiting after treatment. The number of those nauseated is likely
to be even higher. Controlling this side effect can improve a patient’s
sense of well-being and allow them to continue their daily routine
during the course of therapy.
Many chemotherapy agents cause nausea and vomiting by stimulating
proteins in the brain known as NK1 receptors, which trigger the
vomiting response. A new drug called Emend®
(aprepitant) has been developed to block this signal.
In March 2003, the FDA approved Emend for the control of chemotherapy-induced
nausea and vomiting, which occurs both immediately or a day or more
after chemotherapy administration. Emend represents the first approved
drug that controls both delayed and immediate nausea and vomiting.
Emend is taken orally for three days starting one hour before chemotherapy.
Emend was evaluated in two separate studies of more than 1,000 cancer
patients receiving high-dose cisplatin. Patients were given either
standard medication alone (Zofran® [ondansatron]
or Kytril® [granisetron] and Decadron®
[dexamethasone]) or in combination with Emend to control nausea
and vomiting. There was a 20% decrease in the incidence of vomiting
among patients given Emend in addition to standard medication.
To learn more about Emend, visit www.emend.com.
|
