New York

PFIZER INC said on Monday that its drug tafamidis reduced the risk of death for patients with a rare and fatal heart disease by around 30 per cent, boosting the prospects of what could be a billion-dollar-a-year drug.

The study showed that tafamidis reduced all-cause mortality over a 30-month period in patients with transthyretin amyloid cardiomyopathy to 29.5 per cent, versus 42.9 per cent in patients who received a placebo.

It also reduced the rate of cardiovascular-related hospitalisation by around 32 per cent, Pfizer said.

The data was presented at the European Society of Cardiology Congress in Munich.

"The result is really, phenomenally encouraging and gives fantastic hope for patients with this devastating illness," said Dr Brenda Cooperstone, chief development officer of rare disease at Pfizer. "It's a uniformly fatal disease."

Tafamidis is one of 15 potential blockbuster treatments Pfizer is trying to develop. The company's chief executive officer Ian Read has touted Pfizer's pipeline, arguing that the growth potential from these drugs makes undertaking a large transaction unnecessary.

There are currently no approved medications in the United States for transthyretin cardiomyopathy.

The number of patients currently diagnosed with the progressive disease is exceedingly small - somewhere in the range of 2,000 to 5,000 patients globally.

But Pfizer believes the disease is under-diagnosed and that there could be 400,000 to 500,000 patients in developed markets around the world. Dr Cooperstone said the current diagnosis rate is only around 0.5 per cent to one per cent.

"Part of that is driven by the fact that today there is no therapy - there's no reason to actually make the diagnosis," she said, noting that a real treatment should significantly help improve the diagnosis rate.

The US Food and Drug Administration (FDA) gave the drug breakthrough status in May after Pfizer released topline results from the study, which could accelerate the drug's approval.

Dr Cooperstone said Pfizer expects to complete the submission of its application for tafamidis to the FDA in the fourth quarter. The agency has committed to reviewing it as fast as possible, she said, but declined to lay out a timeline for approval.

Until then, Pfizer has established an expanded access programme to make the drug available to patients prior to regulatory approval.

SunTrust Robinson Humphrey analyst John Boris said in a research note last week that a second-half submission to regulators suggests approval and launch of the drug in 2019.

He said that at an annual price of US$150,000 to US$300,000, the drug could bring in US$600 million to US$1.2 billion globally.

The study had around 440 patients enrolled.

Tafamidis was previously rejected by the FDA as treatment for a rare neurodegenerative disease.

But it is currently approved, under the brand name Vyndaqel, in 40 other countries as a treatment for familial amyloid polyneuropathy, a rare, progressive and fatal neurodegenerative disease. REUTERS