While the results are promising,
Zadina’s drug would likely still trigger
a mild euphoria similar to other
narcotics, which would mean the
potential for abuse could still be high.
But Zadina’s team has been working
with investors and biotech companies
to develop the treatment further and
seek approval for human trials.
Researchers are also developing
drugs that act on multiple pain-relieving receptors, including mu,
delta, and kappa. Opioids typically
target the mu receptor, which is what
triggers an opioid “high” along with
an increased tolerance.
One team at the University of
Maryland has created a drug called
UMB425 that hits both the mu and
delta receptors, which, for reasons
that aren’t clear, eliminates several
side effects including rising tolerance.
Just like the drug being developed
by the group at Tulane, however, the
medication still produces euphoria. It
also has been tested only in rodents and
could be years away from human trials.
Another drug that’s gotten a lot
of buzz is PZM21, a synthetic opioid
that was discovered by a team of
scientists from four universities after
they screened more than 3 million
chemical compounds using computer
modeling. Studies on mice showed
that the pain-relieving properties
of the compound last longer
than morphine and didn’t cause
Trevena has also developed a
new opioid called oliceridine that
has been given breakthrough therapy
designation by the U.S. Food and
Drug Administration — putting the
drug on the fast track to approval.
The medication, which is in human
trials, also treats pain without the
same dangerous respiratory side
effects as morphine, but also has
similar addictive-like properties.
“I would say that the next class
of drugs coming out in the next
few years are nerve growth factor
antibodies,” says Clauw.
Chronic pain sufferers often have
higher nerve growth factor levels,
According to Clauw, one of
the most promising therapies is
tanezumab, a drug being developed
by Pfizer and Eli Lilly. The medication
is currently in Phase 3 clinical trials
for low back and chronic pain. But, if
effective, the biggest prize would be
for osteoarthritis treatment.
“That is the main gorilla of the pain
market because almost everyone will
develop osteoarthritis,” Clauw says.
One of the biggest hurdles for
new biologics, however, will be the
“The average biologic starts at
$20,000 to $30,000 and goes up,”
Clauw says. “The analgesic space
has never seen anything like that for
Cues From Nature
Some scientists are finding that
nature provides plenty of answers for