7:04AM ISIS Pharm earns $10 mln milestone payment from AstraZeneca (AZN) for ISIS-AR Rx to treat prostate cancer (ISIS) 21.69 : Co announces that AstraZeneca has added a second development candidate, ISIS-ARRx, to its collaboration with Isis. Isis earned a $10 mln milestone payment associated with this decision. ISIS-ARRx is an antisense drug designed to treat patients with prostate cancer by inhibiting the production of the androgen receptor. AstraZeneca is planning to develop ISIS-ARRx broadly to treat patients under a variety of settings during the course of prostate cancer treatment, including both as a single agent and in combination therapy.