US-based Nektar Therapeutics (NKTR) released their second quarter earnings report on Aug 8, showing the company narrowly beat earnings loss expectations. As a result, the stock shot up over 12 percent on Aug. 9. But concerns still linger concerning the release of an amendment to a deal with Anglo-Swedish company Astrazeneca plc (AZN) that could negatively affect the company, and Nektar's stock corrected in kind.

The amendment concerns the drug Naloxegol. The drug is designed to counteract constipation brought upon by opioid pain-killing treatments, and is still under development. A previous incarnation of the deal had Nektar collecting a $70 million milestone payment in connection with the drug being accepted by the FDA. That payment has been deferred.

Nektar’s CEO Howard Robin outlined the new structure of the deal with AstraZeneca in the earnings call, saying “If the FDA requires a preapproval cardiovascular safety study for Naloxegol and AstraZeneca decides not to do this study and terminates the agreement in the US, but moves forward with launching the product in Europe, the $70 million US milestone payment that we receive from AstraZeneca will be converted into a long-term loan which will be paid back from 50% of the future royalties on Naloxegol in Europe and the rest of the world. In this event, all US rights to Naloxegol will be returned to Nektar.”

Per the amendment, AstraZeneca could actually cut their ties with the drug entirely if things don’t work out. Nektar reiterated in their SEC filing that they still expect the payout, and have not significantly changed their projections for their year-end cash position. The company still expects to have $200 million in cash and marketable securities by the end of 2013.

On Aug. 8 Nektar reported a net loss of $42.7 million, or -$0.37 per share, versus the loss of $34.82 million, or -$0.30 per share, from the same period a year ago. Revenue for the quarter was $33.9 million, as compared to $23.6 million from the previous year. Analysts were expecting a loss of -$0.43 per share on revenues of $24 million.

Nektar's stock is down 6.04 percent to $11.66 a share.