By
Elizabeth Whittington
Multiple Myeloma
Revlimid Receives Nod for Multiple Myeloma
Six months after its approval for myelodysplastic syndromes, Revlimid® (lenalidomide)
was approved in late June for patients with multiple myeloma whose
disease progressed despite prior therapy. Multiple myeloma, the
second most common blood cancer, will be diagnosed in about 16,000
Americans in 2006. Caused by a cancerous growth of plasma cells
that can cause damage to bone tissue, multiple myeloma can cause
bone pain, fractures, kidney failure, anemia and an increased risk
of infection.
The approval was based in part on positive results
from a large study with myeloma patients whose disease was either
unresponsive to previous chemotherapy or relapsed after first-line
chemotherapy treatment. Revlimid, an oral drug taken daily, combined
with the steroid Decadron® (dexamethasone), increased overall
survival when compared with patients who received Decadron alone.
Half the patients on the Revlimid arm lived longer than 30 months
compared with 20 months for the Decadron-alone arm. The main side
effects of Revlimid are a decrease in white blood counts, anemia
and fatigue.
Revlimid is currently available through a restricted
distribution program called RevAssist, which requires doctors and
pharmacists to register in order to prescribe the drug. For more
information on Revlimid, visit www.revlimid.com.
Leukemia
Two Drugs for Gleevec-Resistant CML
An estimated 4,500 people will be diagnosed
in 2006 with chronic myeloid leukemia (CML), a disease caused by
an overgrowth of white blood cells in the bone marrow and peripheral
blood. Characterized by a chromosomal abnormality called the Philadelphia
chromosome, CML cells produce an abnormal protein that is now considered
the principle cause of the disease.
Although Gleevec® (imatinib)
is effective in most CML patients, it is estimated that 4 percent
of newly diagnosed CML patients do not respond to Gleevec, and
up to 20 percent of patients may either not be able to tolerate
Gleevec due to side effects or develop resistance to Gleevec over
time. The risk of resistance increases with the number of years
the patient received prior treatment and severity of the disease.
Patients with advanced CML or a rare form of acute leukemia called
Philadelphia chromosome-positive acute lymphoblastic leukemia (ALL) generally
develop resistance more rapidly.
Two new drugs have helped fill the void in Gleevec-resistant
CML. In June, data from several studies were considered positive
enough for the Food and Drug Administration to grant accelerated
approval to Sprycel™ (dasatinib) for CML patients
with a resistance or intolerance to Gleevec or other CML therapies. Now in phase
III testing for CML, an earlier trial comparing Sprycel with high-dose Gleevec
found more patients responded to Sprycel, and for a longer period of time, compared
with Gleevec. The FDA also granted full approval of Sprycel for Philadelphia
chromosome-positive ALL. Common side effects of Sprycel include diarrhea, nausea
and abdominal pain.
The makers of Gleevec
plan to file for approval of another CML drug called Tasigna®
(nilotinib) in late 2006. Preliminary study results show more than
90 percent of patients with Gleevec-resistant CML in chronic phase
responded to the drug, which was also found to be very tolerable.
Scientists are now studying a variety of combinations with Gleevec,
Sprycel and Tasigna. For information on Sprycel, visit www.sprycel.com,
and for more on Tasigna, visit www.novartis.com.
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