Alnylam Pharmaceuticals has reported new positive results from the Phase l/ll clinical trial evaluating lumasiran for the treatment of primary hyperoxaluria type 1 (PH1).

The results revealed that lumasiran showed a mean maximal reduction in urinary oxalate of 75% relative to baseline across cohort of patients who received a 1mg/kg monthly or 3mg/kg monthly or quarterly dose of lumasiran.

The mean reduction relative to baseline was reported to be 66% when measured 28 days after the last dose.

In addition, the results found that 83% of the patients receiving 3mg/kg monthly or quarterly doses of lumasiran attained urinary oxalate levels within the normal range.

All patients treated with lumasiran experienced a mean maximal decrease of 76% in the ratio of urinary oxalate to creatinine.

The safety data from the trial are based on a median study period of seven months since the administration of the first dose.

Only one patient treated with placebo and five patients receiving lumasiran experienced serious adverse events (SAEs), none of them were related to lumasiran.

“Once the kidneys fail, the only viable therapeutic option is a dual liver/kidney transplant.”

Phase l/ll trial investigator Pierre Cochat said: “PH1 is an ultra-rare disease characterised by an inevitable and progressive decline in kidney function leading to systemic manifestations and ultimately multi-organ dysfunction.

“Once the kidneys fail, the only viable therapeutic option is a dual liver/kidney transplant.

“Given the profound unmet need in this disease setting, the Phase l/ll results presented for lumasiran are encouraging, particularly in light of the clinically meaningful effect of lumasiran on lowering urinary oxalate for every patient relative to their baseline and with all patients achieving near normal levels of oxalate.”

Furthermore, Alnylam started the Phase lll ILLUMINATE-A trial to evaluate lumasiran in children and adults with PH1.

The trial is expected to enrol around 30 patients and plans to report top-line results next year.

Its primary endpoint is reduction of urinary oxalate at six months.