A new type of heart drug developed by Medicines Co significantly lowered "bad" LDL cholesterol in high-risk patients with no major safety issues.
This is according to data from a mid-stage trial that helped the company move into advanced testing.
The drug, called inclisiran, belongs to a new class of drugs that inhibit a protein known as PCSK9, which prevents the removal of LDL from the blood.
But the Medicines Co drug works in a different way than the two already on the market and is given far less frequently.
The study tested several strengths of inclisiran against a placebo in about 500 patients, many of whom had had a prior heart attack or stroke.
All had high LDL levels despite most being on high doses of cholesterol-lowering statins.
The study found 300mg to be the minimum dose to achieve maximum efficacy.
That dose will be used in larger phase III trials aimed at winning regulatory approval, the company said.
One 300mg dose of inclisiran led to an average lowering of LDL by 51 per cent at day 60, which was maintained over three months.
Two 300mg injections given on day one and day 90 on average took LDL down by 57 per cent at day 120, and maintained its effectiveness over six months.
The data indicates the drug "is likely to ensure significant and durable reductions in LDL cholesterol and could potentially impact cardiovascular outcomes," said Kausik Ray, who presented the data at an American Heart Association meeting in New Orleans recently.
Borge Nordestgaard, who was not involved in the study, called the data "really, really encouraging".
Only 189 patients were available for evaluation over 180 days. Six-month data for all patients is expected by year-end.
Inclisiran is designed to be taken just twice or three times a year.
Amgen's Repatha and Praluent from Regeneron Pharmaceuticals and Sanofi are injected every two or four weeks.