UPDATE 1-Norway's Clavis signs $380 mln cancer drug deal

* Development deal with U.S.-based Clovis Oncology

* Deal value could rise due to royalties

* Clavis stock up over 60 pct

(Adds details, comments, share price)

By Aasa Christine Stoltz and Joachim Dagenborg

OSLO, Nov 24 (Reuters) - Norwegian pharmaceutical company Clavis Pharma (CLAVIS.OL) said on Tuesday it had signed a cancer drug development deal worth around $380 million with U.S.-based Clovis Oncology, boosting its shares as much as 86 percent.

The deal is for the development and commercialisation of pancreatic cancer drug CP-4126 and the payments, -- which include a $15 million signing fee and tiered double-digit royalties on sales -- will be made in stages.

Shares in Clavis were still up 63 percent at 53.50 crowns by 0823 GMT, against a 0.6 percent drop in the main index at Oslo bourse .OSEBX. Clavis Pharma said it would "receive an upfront cash payment of $15 million from Clovis Oncology and will be eligible to receive further payments totalling up to $365 million on Clovis Oncology's successful attainment of development, regulatory and sales milestones".

Chief Executive Geir Christian Melen told Reuters that the total potential was higher than the $380 million due to royalties on sales.

"To received the total payment, the product needs to go through the regular clinical development phases, to get through processes of approval and reach the market," Melen said.

Clovis Oncology will commercialise CP-4126 in the United States, Europe, Canada, Central and South America.

The drug is currently in Phase II development in pancreatic cancer and has "potential to improve treatment outcomes in a large subset of patients with pancreatic cancer and certain other solid tumours," the company said.

"This is without a doubt very positive news," analyst Espen Tidemann Joergensen at DnB NOR Markets said. "It was much bigger than what we had expected."

Clavis said it had started the process of looking for a partner for the development of its second product, Elacytarabine, a cancer drug for the treatment of blood related cancer currently in Phase III. (Reporting by Aasa Christine Stoltz and Joachim Dagenborg; Editing by Dan Lalor and Simon Jessop) ((aasachristine.stoltz@reuters.com; +47 22 93 69 02; Reuters messaging: rm://aasachristine.stoltz.reuters.com@reuters.net))