Alnylam Pharmaceuticals ( ALNY) and Isis Pharmaceuticals ( ISIS) dished on a new microRNA company, and varying news sent other health stocks in both directions on Friday. Alnylam and Isis announced the launch of Regulus Therapeutics, a joint venture focused on microRNA (miRNA) therapeutics, an approach to targeting the pathways of human disease. It will be run as an independent company with an independent board of directors and management team. Alnylam is making an initial investment of $10 million, and both companies will share funding of the venture thereafter. Both companies will grant Regulus exclusive licenses to their intellectual property for miRNA therapeutic applications and patents in the miRNA field. Alnylam and Isis said they'll retain the rights to develop and commercialize on prenegotiated terms miRNA therapeutic products that Regulus decides not to develop independently or with a partner. Shares of Alnylam added $1.03, or 4%, to $26.88, while Isis lost 24 cents, or 2%, to $12.50. Both companies are components of the Nasdaq biotechnology index, which was down 9.25, or 1.1%, to 827.55 on Friday. In another collaborative effort, Pozen ( POZN) said it amended its Aug. 2006 license agreement with AstraZeneca ( AZN) and started the phase III program for PN 400, a fixed-dose combination of the proton-pump inhibitor, esomeprazole magnesium, with the non-steroidal anti-inflammatory drug naproxen, in a single tablet.