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Alnylam Presents Data on Complement Component 5-targeting Drug


Alnylam Pharmaceuticals last week released preclinical data on ALN-CC5, an RNAi-based drug targeting complement component 5 and the newest addition to its product-development pipeline.

The complement system is involved in immunity as a protective mechanism for host defense, according to the company. Dysregulation of the system can create serious complications in a variety of diseases including paroxysmal nocturnal hemoglobinuria, atypical hemolytic-uremic syndrome, myasthenia gravis, and neuromyelitis optica.

Complement component C5, which is primarily expressed in liver cells, is a validated target whose loss is associated with an “attenuated immune response” against certain infections, Alnylam added.

The company said that its preclinical data shows that ALN-CC5 can trigger dose-dependent and durable RNAi-mediated knockdown of serum C5 and inhibition of complement-mediated hemolytic activity of approximately 90 percent after subcutaneous administration.

“Specifically, a prototype GalNAc-siRNA conjugate targeting C5 showed a single dose ED50 for C5 knockdown of approximately 0.6 mg/kg in rodent models,” Alnylam said. “In multi-dose experiments, subcutaneous administration of the GalNAc-siRNA conjugate resulted in approximately 90 percent knockdown of serum C5 levels at doses [at or greater than] 1.25 mg/kg.”

Additionally, in multi-dose experiments, the company’s lead drug candidate achieved about 90 percent inhibition of complement-mediated hemolytic activity in the rat at subcutaneous doses of 5 mg/kg.

The data were presented at the International Conference on Complement Therapeutics held earlier this month in Greece.

Alnylam expects to nominate its ALN-CC5 candidate before the end of this year.

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