Ionis Pharmaceuticals (NASDAQ:IONS) IONIS-TTRrx and Alnylam Pharmaceuticals' (NASDAQ:ALNY) patisiran have experts debating their long-term safety profiles as well as potential points of clinical differentiation.
Experts noted that safety to date in clinical trials has been acceptable. However, the full functions of TTR remain unknown and aggressive TTR knockdown could lead to long-term off-target effects. Experts agreed that there appeared to be little to differentiate the drugs at this point in time.
IONIS-TTRRx is an antisense drug designed to reduce the production of TTR and is delivered by injection.
Patisiran employs a TTR-targeting siRNA that knocks down both wild-type and all mutant forms of TTR in an intravenous lipid nanoparticle formulation.
Both drugs are under investigation in Phase III trials (NCT01737398/NCT01960348). This news service reported on 29 July that both drugs had experts excited about their Phase III efficacy potential.