NEW YORK (TheStreet) -- Nektar Therapeutics (NKTR - Get Report) shares are up 9.8% to $12.13.

The rise follows an initiation of coverage with a "buy" rating and $15 price target by analysts at Jefferies Group (JEF).

The positive rating comes on speculation about the approval of the drug manufacturer's once a day opiod-induced constipation relieving pill, Naloxegol, which Jefferies believes could provide a major boost to the company's bottom line.

The FDA panel reviewing the drug is set to meet in mid-June.

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