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FDA panel votes 10-1 against Otsuka's combination drug for

PTSD

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Panel's decision echoes FDA reviewers' efficacy concerns

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Mixed trial results and adverse events raise doubts

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FDA decision on drug delayed

(Adds comments from panelists in paragraphs 5,7,8, background

throughout)

By Mariam Sunny and Siddhi Mahatole

July 18 (Reuters) - The U.S. Food and Drug

Administration's panel of independent advisers on Friday voted

against the efficacy of Otsuka Pharma's antipsychotic

drug in combination with Viatris' ( VTRS ) antidepressant Zoloft

for treating adults with PTSD.

The panel voted 10-1 to say the available data does not

establish the efficacy of the drug, brexpiprazole, in

combination with Zoloft, chemically known as sertraline, for

treating the condition. Its decision is in line with the FDA

staff reviewers' assessment on Wednesday.

Otsuka's application was based on the data from one

mid-stage and two late-stage studies testing the combination

treatment compared to sertraline plus placebo. It had failed to

meet the main goal of significantly reducing severity of PTSD

symptoms in one of the late-stage studies compared to sertraline

and placebo.

PTSD, a disorder caused by very stressful events, affects

about 4% of U.S. adults and is commonly associated with war

veterans. But natural disasters, abuse or other trauma may also

trigger the condition in civilians.

"We simply cannot negate one negative study and say we are

going to approve based on two other positive studies," said

panelist Pamela Shaw, biostatistician at Kaiser Permanente.

Otsuka did not immediately respond to a Reuters request for

comment.

The advisers discussed possible side-effects such as weight

gain and movement disorders associated with long-term use of

antipsychotics, but noted that the combination may be a better

treatment option for patients who respond poorly to sertraline

alone.

"The big question for me is knowing that antipsychotics can

cause real problems, especially with long-term use, and the

modest benefit that the combination treatment potentially can

offer," said panelist Walter Dunn, assistant clinical professor

of psychiatry at university of California Los Angeles.

The FDA, originally set to decide on the company's

application by February 8, delayed its decision to seek the

advisory panel's input. The agency has not set a new action date

for the drug.

The health regulator typically follows the advice of its

expert advisers, but is not required to do so.

If approved, the combination drug would be the first PTSD

treatment to gain U.S. nod in more than two decades after Zoloft

and GSK's Paxil.

Brexpiprazole, branded as Rexulti, is approved in the U.S.

to treat agitation in patients with Alzheimer's disease as well

as for adults with major depressive disorder and schizophrenia.

The drug is being co-developed by Otsuka and Danish

drugmaker Lundbeck.