Researchers
have discovered a class of FDA-approved antidepressants that may prove
effective in treating patients with small-cell
lung cancer – one of the deadliest forms of the disease.
Small-cell
lung cancer (SLC) comprises 15 percent of all lung cancers and has a
particularly grim prognosis rate.
“SLC
is a bad cancer to have,” Dr. Atul Butte, the study’s lead author of the
Stanford University School of Medicine. “The
five-year survival is only 5 to 6 percent, and most people present with
extensive stage cancer.”
The
disease is a form of cancer known as neuroendocrine cancer – the same type of
cancer that Steve Jobs was diagnosed with – for which few targeted
treatments are available.
Rather
than developing new drugs to treat diseases like SLC, Butte and his colleagues
have long been interested in the concept of identifying already FDA-approved
drugs that might be repurposed to treat new disorders. With this purpose in
mind, Butte’s laboratory developed a computer algorithm able to identify drugs
that target genes associated with certain diseases – and match them with one
another.
“Basically,
a report in the past called for drugs,” Butte said.
Using
this computerized discovery pipeline, the researchers began to explore whether
any existing drugs might prove effective at killing SLC cells.
“What
we started with was looking at experiments where people submitted normal tissue
and SLC tissue from the same patients,” Butte said. “We (identify) the gene
that is most different in the cancerous cells and then find a drug to reverse
that effect.”
Eventually,
researchers hit upon a drug called imipramine, which is part of a class of
FDA-approved drugs known as tricyclic antidepressants. When researchers exposed
SLC-infected tissues to imipramine, the cancerous cells appeared to die off.
Researchers tested the drug with success in both a lab setting and using mice
genetically engineered to develop small-cell lung cancer.
While
tricyclic antidepressants are still on the market, they’ve been overshadowed by
the popularity of newer classes of antidepressants, including
selective-serotonin reuptake inhibitors (SSRIs), like Prozac, which have been
proven to have fewer side effects.
“But
not so long ago (tricyclic antidepressants) were commonly used,” Butte said.
“They do have side effects, the biggest is on the heart, like arrhythmia… that
being said these drugs are still in the pharmacy and you can get them.”
Because
these drugs are already FDA-approved, researchers were able to start recruiting
patients for phase 2 clinical trials within 15 to
20 months of their discovery.
“Usually
it takes $4 billion and 10 plus years to get a brand new drug to market,” Butte
said. “This could be a shortcut – finding a drug that works and borrowing it
for other disease. We don’t know yet if the trial will work or not but its
amazing it will get to trial so quickly.”
However,
Butte warns that just because the drug is already on the market, doesn’t mean
that patients should attempt to self-medicate.
“We
would strongly encourage them to join a trial and get this kind of medication in a research
setting, making sure they’re following safety guidelines for this category,”
Butte said.
Source;
http://medicalxpress.com/news/2013-09-fda-approved-antidepressant-combat-deadly-lung.html
No comments:
Post a Comment