By Tamara Mathias and Ruhi Soni

(Reuters) – Alnylam Pharmaceuticals Inc’s gene-silencing therapy for a rare kidney disorder met the main goal of a late-stage study on Tuesday, bringing the company a step closer to marketing the first approved treatment for the condition.

The study tested Alnylam’s experimental drug, lumasiran, against placebo in patients aged six and above with primary hyperoxyluria type 1 (PH1), a life-threatening condition that is estimated to affect one in 58,000 people globally.

Alnylam plans to file for the drug’s approval in the United States and Europe early next year and hopes to launch the drug before the end of 2020.

The company’s president, Barry Greene, estimates the market opportunity for PH1 treatments to be over $500 million.

Lumasiran works using a mechanism called RNA interference (RNAi) to target and “silence” the genetic material involved in making excess amounts of a chemical called oxalate.

Excess oxalate builds up in the kidneys of patients with PH1, eventually leading to kidney and bladder stones. In severe cases, they may have to undergo dialysis, kidney or liver transplants.

In the trial, lumasiran was found to significantly reduce the production of oxalate in patients taking a monthly dose for three months, followed by maintenance doses, compared to those administered with a placebo.

Needham analyst Alan Carr had forecast global peak sales of between $450 million and $500 million for lumasiran in 2032, before the trial results were announced.

Alnylam already has two gene-silencing treatments in the market for rare hereditary disorders.

In 2018, Onpattro, Alnylam’s treatment targeting a symptom of a potentially fatal condition called hereditary ATTR amyloidosis, became the first RNAi treatment to be approved in the United States. (

In November, the company received approval for Givlaari to treat acute hepatic porphyria, a rare disorder that can lead to severe pain and paralysis, respiratory failure and seizures.

(Reporting by Ruhi Soni and Tamara Mathias; Editing by Vinay Dwivedi)