Silence Therapeutics Achieves $10 Million Milestone Payment from AstraZeneca Collaboration Following the Initiation of Phase 1 Trial

Silence Therapeutics plc, Nasdaq: SLN (“Silence” or “the Company”), an experienced and innovative biotechnology company committed to transforming people’s lives by silencing diseases through precision engineered medicines, today announced that the initiation by AstraZeneca of a phase 1 clinical trial of the first product candidate under its siRNA (short interfering RNA) collaboration, has triggered a $10.0 million milestone payment to Silence.

“This represents the first clinical milestone under our collaboration with AstraZeneca and the third program to enter the clinic from our mRNAi GOLD platform,” said Craig Tooman, President and CEO of Silence. “This is a very exciting time for Silence as we are beginning to establish ourselves as a platform company progressing multiple clinical programs targeting both rare and common genetic diseases. In addition to this great achievement under our collaboration with AstraZeneca, we are also pleased with the continued advancement of our proprietary pipeline with encouraging clinical data now emerging from our zerlasiran program in high Lp(a) and divesiran program in polycythemia vera.”

“We are pleased to have achieved this important clinical milestone through our collaboration with Silence Therapeutics. Our goal in working together is to advance these novel programs and develop the next wave of innovative therapies that address cardiovascular, renal and metabolic diseases,” said Regina Fritsche Danielson, SVP, Early Cardiovascular, Renal and Metabolism, BioPharmaceuticals R&D, AstraZeneca.

Silence and AstraZeneca initiated a multi-target collaboration in March 2020 focused on using Silence’s proprietary mRNAi GOLD platform to develop siRNA therapeutics for cardiovascular, renal, metabolic and respiratory diseases. Under the agreement, AstraZeneca will pay Silence an option fee of $10 million for each selected target at the point of candidate nomination. The deal covers up to ten targets. For each target selected, Silence is eligible for up to $140 million in development milestones and up to $250 million in commercialization milestones as well as tiered royalties on net sales ranging from high single digit to low double digit.