The International Court of Arbitration ruled against Sucampo on Friday in a dispute resulting from the biotechnology company's dissatisfaction with Takeda's marketing of its constipation drug, Amitiza.

Sucampo shares fell more than 28 percent in early trade, making them one of the biggest losers on the Nasdaq. They were later trading at $5.25 after touching a more than five-month low of $4.99.

The company, which had sought damages and wanted to dissolve its tie-up with Takeda, depends on Amitiza for most of its revenue, derived from royalties paid by Takeda.

Sucampo, which signed the deal with Takeda in 2004, began arbitration in 2010, alleging that its Japanese partner's meek marketing of Amitiza had failed to drive satisfactory sales.

"We are disappointed with this decision but remain committed to working with Takeda to maximize patient access to Amitiza. However, the company is evaluating all of its options," a Sucampo spokeswoman told Reuters.

Sucampo said the court disagreed with its claims and denied it any attorneys' fees or costs.

Amitiza sales rose 20 percent to $60.7 million for the quarter ended March 2012, and Sucampo received a royalty revenue of $10.9 million for the period.

The court ruling means that all the originally set terms in the agreement, including royalty arrangements, will remain unchanged, until the deal expires in October 2020.

Sucampo hopes to convince Takeda to improve sales of the product by "favorably positioning Amitiza with managed care plans," and increased branding.

Amitiza, which gained U.S. approval to treat idiopathic constipation in 2006 and irritable bowel syndrome with constipation in 2008, is marketed by Takeda in the United States.

Sucampo has an agreement with Abbott Japan Co Ltd, a unit of Abbott Laboratories, to launch Amitiza as a treatment for chronic constipation in Japan, where the drug is expected to be available in the fourth quarter.

The company said it plans to file for U.S. approval of the drug for a third indication - opioid-induced constipation - in the near term.

(This story corrects spelling of drug name in paragraphs 2,4; also clarifies that Sucampo depends on Amitiza for most, not all, of its revenue and removes erroneous reference to the company's pipeline in paragraph 4)

(Reporting by Zeba Siddiqui in Bangalore; Editing by Viraj Nair)

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