AstraZeneca PLC decided to terminate a 2012 collaboration agreement with Regulus Therapeutics Inc. to discover and develop microRNA therapeutics for cardiovascular diseases, metabolic diseases and oncology.
The termination becomes effective June 9, 2018.
Pursuant to the agreement, Regulus granted AstraZeneca an exclusive, worldwide license to develop, manufacture and commercialize lead compounds designated by AstraZeneca in the course of the collaboration activities against the alliance targets for all human therapeutic uses.
The companies identified RG-125 or AZD4076 as one such clinical candidate in April 2015. Effective upon the termination of the agreement, AstraZeneca's rights with respect to the drug will revert to Regulus.
Regulus also said it will discontinue clinical development of RG-101, a microRNA treatment for hepatitis C, upon completion of the one remaining clinical study, which is expected to occur in July.
Investigation and thorough evaluation of the clinical data from RG-101 has led to the identification of a bilirubin transport mechanism as the likely cause for the cases of hyperbilirubinemia, a condition in which there is too much bilirubin in the blood, in the RG-101 program.
The company believes that a combination of factors including inhibition of conjugated bilirubin transport by RG-101, impaired baseline bilirubin transport in patients and the preferential uptake of RG-101 by hepatocytes contributed to this mechanism.
Applying the learnings from the RG-101 program, alternative compounds targeting miR-122 have been identified that maintain potent hepatitis C antiviral activity while lacking inhibition of the bilirubin transporter. These compounds have the potential for rapid clinical proof-of-concept of a novel, markedly shortened treatment regimen and will be considered for further development pending an updated global commercial market assessment.
RGLS5040, an unconjugated inhibitor of microRNA27, has been discontinued based on a positioning of the compound with respect to the competitive landscape coupled with the results from repeat pharmacology studies. The company continues to work on developing effective therapeutics for genetic forms of cholestatic disease as part of its overall research activities targeting unmet diseases of the liver and kidney.