UPDATE 2-Aeterna/Keryx soar on perifosine orphan drug status

* Orphan status for treatment for type of pediatric cancer

* Aeterna shares up as much as 12 pct

* Keryx shares up as much as 17 pct

TORONTO, July 14 (Reuters) - Drugmakers Aeterna Zentaris Inc (AEZ.TO) and Keryx Biopharmaceuticals Inc (KERX.O) said on Wednesday their experimental cancer drug, KRX-0401, has received orphan drug status from U.S. health regulators for the treatment of a type of childhood cancer.

Keryx rose as much as 17 percent and Aeterna shares were up nearly 12 percent following the news.

The U.S. Food and Drug Administration approved KRX-0401, also known as perifosine, for the treatment of neuroblastoma, a tumor that affects developing nerve tissue and which accounts for about 7 percent of all cancer deaths in children. There are currently no FDA approved treatments available.

The FDA's orphan drug status is reserved for new treatments that are being developed for diseases or conditions that affect fewer than 200,000 people in the United States.

The status grants the drug developer seven years of market exclusivity, upon approval.

Quebec-based Aeterna, a late-stage drug development company that specializes in oncology and endocrinology, is partnered with New York-based Keryx, which Aeterna has licensed to develop and market perifosine in the United States, Canada and Mexico.

Aeterna has also licensed perifosine to Handok Pharmaceuticals (002390.KS) in South Korea, but retains the rights everywhere else.

KRX-0401 is currently also in a late-stage trial as a treatment for colon cancer and a type of cancer called multiple myeloma. It is in early-stage trials for neuroblastoma.

The drug previously received FDA orphan drug status for multiple myeloma.

Shares of New York's Keryx were up 13.8 percent at $4.05 on the Nasdaq after touching a high of $4.18 earlier in the session. Aeterna shares climbed 9 Canadian cents, or 8 percent, to C$1.22 after hitting C$1.26.

($1=$1.03 Canadian) (Reporting by Solarina Ho in Toronto and Shailesh Kuber in Bangalore; editing by Peter Galloway)