Alnylam Pharmaceuticals this week released final data from a phase I study of its TTR-mediated amyloidosis drug ALN-TTR01, which showed the compound triggered dose-dependent and durable reductions in target protein levels.
ALN-TTR01 comprises siRNAs against transthyretin, or TTR. Alnylam previously stated that it intends to advance a different version of the drug called ALN-TTR02, which uses a second-generation lipid delivery vehicle and is in phase I testing, to the market.
According to the company, the randomized, placebo-controlled, single-dose escalation study enrolled 32 ATTR patients in seven sequential, four-patient cohorts of increasing doses ranging from 0.01 mg/kg to 1.0 mg/kg.
Following the completion of dose escalation, additional patients were enrolled at 1.0 mg/kg. In total, eight patients received placebo and 24 received ALN-TTR01.
“ALN-TTR01 demonstrated a dose-dependent reduction in serum TTR levels with a statistically significant mean reduction of 38 percent at approximately day 7 to 10 in the 1.0 mg/kg group,” Alnylam said. “The rapid onset and durable effect of ALN-TTR01 after a single dose was exemplified by one patient dosed at 1.0 mg/kg who showed 63 percent TTR lowering at 48 hours, peak TTR knockdown of 81 percent at day 10, approximately 50 percent lowering at 30 days post dose, and full recovery only at 60 days.”
Alnylam noted that the drug appeared safe and well-tolerated, with only one patient discontinuing the study due to an unrelated adverse event.
The data were presented at the XIII International Symposium on Amyloidosis in the Netherlands.