7:01AM ISIS Pharm earns $7 mln in milestone payments from GSK for advancement of ISIS-GSK3 Rx to treat viral infection (ISIS) 36.07 : Co announced that GlaxoSmithKline has added a development candidate ISIS-GSK3Rx, to its collaboration with Isis. Isis earned $7 mln in milestone payments associated with the advancement of this program. ISIS-GSK3Rx is an antisense drug designed to inhibit the production of an undisclosed target to treat a common viral infection. Isis will develop ISIS-GSK3Rx to Phase 2 proof-of-concept, after which GSK has an exclusive option to in-license the program and further develop and commercialize the asset.