Sanofi RNAi drug shows sustained benefit in hemophilia patients

Sanofi (SNY +2.1%) announces preliminary results from a 34-subject Phase 2 open-label extension study evaluating RNAi candidate fitusiran in patients with moderate-to-severe hemophilia A or B with or without inhibitors. The data were presented at the World Federation of Hemophilia Virtual Summit.

Patients receiving monthly subcutaneous doses of fitusiran and followed for as long as 4.7 years (median exposure of 2.6years) experienced sustained lowering of antithrombin (~75% from baseline) resulting in median peak thrombin values at the lower end of the normal range. Thrombin is an enzyme that causes the blood to clot. Antithrombin is an antibody that binds to (inactivates) thrombin thereby interfering with clotting.

Median annualized bleed rate (ABR) overall was 0.84. Median ABR in the non-inhibitor subgroup was 1.01 and 0.44 in the inhibitor subgroup.

Overall, the rate of spontaneous bleeds was a median of 0.38. Median rates in the non-inhibitor and inhibitor groups were 0.33 and 0.39, respectively.

No cases of anti-fitusiran antibody formation were observed.

On the safety front, the most common adverse events were: increase in ALT (29%) (enzyme biomarker of liver stress/damage), injection site erythema (reddening of the skin) (21%), nasopharyngitis (21%), upper respiratory tract infection (18%), diarrhea (18%), arthralgia (joint pain) (18%), back pain (18%) and increased transaminases (liver enzymes) (15%).

Results from Phase 3 studies should be available in H1 2021.

https://seekingalpha.com/news/3584552-sanofi-rnai-drug-shows-sustained-benefit-in-hemophilia-patients