Amylin Pharmaceuticals and Eli Lilly are to dissolve their agreement surrounding diabetes medications Byetta and Bydureon.

Amylin is to receive all rights related to both medications for a one-time, upfront fee of $250m, with 15% of global net sales in revenue-sharing payments payable to Lilly up to $1.2bn.

The agreement relies on Bydureon receiving US Food and Drug Administration (FDA) approval before 30 June 2014, with Lilly set to receive 8% of sales of exenatide products should the drug not be rubber-stamped for use in the US.

Lilly could also receive a one-off milestone payment of $150m from Amylin should a once-monthly suspension version of the drug, currently in a Phase II trial, be approved by the FDA.

Both parties insisted the split was amicable despite Amylin citing a potential conflict of interest when Lilly signed a separate diabetes agreement with Boehringer Ingelheim.