Shares in the London-listed company, which specializes in addiction
treatment, were 11 percent higher by 0855 GMT on Wednesday on the
overnight news, extending gains this week.
The advisory committee to the U.S. Food and Drug Administration
(FDA) voted 18-1 that Indivior's injectable drug, known as RBP-6000,
could benefit addicts and the lower of two doses studied had an
acceptable safety profile.
The FDA, which is due to make a decision on the medicine by Nov. 30,
typically follows the recommendations of its advisory panels.
The endorsement comes less than a week after FDA Commissioner Scott
Gottlieb announced the agency's plans to encourage widespread use
among opioid addicts of less harmful opioids such as methadone and
buprenorphine, the active ingredient in RBP-6000.
"I think this is a really promising alternative to what's out there
and will be attractive to a lot of patients," said Laurel Habel, a
panelist and researcher at Kaiser Permanente in Oakland, California.
The United States is battling an opioid abuse epidemic that in 2015
killed 33,000 people. President Donald Trump recently declared the
problem a national public health emergency.
Indivior studied two dosing regimens. In one, 300 milligrams were
given once a month for six months. In the other, two doses of 300
milligrams were followed by four doses of 100 milligrams. There was
little difference in effectiveness between the two doses and the
higher dose caused more side effects.
Panelists said they would like to see more data about which patients
should be given the higher dose, though some said they would like to
have it available despite the lack of data supporting any additional
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If approved the product would be the first monthly injectable
buprenorphine treatment. Indivior already sells Suboxone Film, a
product which combines buprenorphine and nalexone and is placed
under the tongue or inside the cheek.
Two months ago Indivior shares plunged following a U.S. court ruling
that cleared the way for a generic rival to Suboxone Film.
Stifel analyst Max Herrmann said RBP-6000 could capture about 30
percent of the broader buprenorphine market and he expects it to
generate annual sales of around $700 million by 2021. Jefferies sees
potential peak sales of $1.3 billion by 2025.
Lund, Sweden-based Camurus and privately held Braeburn
Pharmaceuticals are also awaiting the health regulator's decision on
their weekly and monthly injectable buprenorphine drug, CAM2038.
Herrmann forecast these once-monthly formulations, RBP-6000 and
CAM2038, to garner around 50 percent of the buprenorphine market,
just short of the 56 percent Suboxone currently enjoys.
(Additional reporting by Divya Grover and Justin Varghese in
Bengaluru; Editing by Shounak Dasgupta and Mark Potter)
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