New Medicines

Haemophilia A and B


New molecular entity
Alnylam Pharmaceuticals
Alnylam Pharmaceuticals

Development and Regulatory status

Phase I Clinical Trials
Phase I Clinical Trials

Aug 14: Orphan drug designation in the EU. [1]


RNA interference (RNAi) therapeutic targeting antithrombin (AT)
Haemophilia A is defined by loss-of-function mutations in Factor VIII, and there are greater than 40,000 registered patients in the U.S. and E.U. Haemophilia B, defined by loss-of-function mutations in Factor IX, affects greater than 9,500 registered patients in the U.S. and E.U. [1]
Haemophilia A and B

Trial or other data

Aug 14: Top-line data from Part A of Phase 1 study, in adult healthy volunteers (n=4, 3:1 drug:placebo). Initial results showed that a single, low subcutaneous ALN-AT3 dose of 0.03 mg/kg resulted in an up to 28-32% knockdown of antithrombin (AT) at nadir (p<0.01). This resulted in a statistically significant (p<0.01) increase in peak thrombin generation, that was temporally associated and consistent with the degree of AT knockdown. ALN-AT3 was found to be well tolerated with no significant adverse events reported. Part B of the study to be initiated: open-label, multi-dose, dose-escalation study in up to 18 people with moderate to severe hemophilia A or B. The primary objective of this part of the study is to evaluate the safety and tolerability of multiple doses, specifically three weekly doses, of subcutaneously administered ALN-AT3 in hemophilia subjects. [1]