The Food and Drug Administration has approved a new medicine for a deadly genetic heart condition, boosting its developer, BridgeBio Pharma, and teeing up a battle for control of a lucrative market targeted by several drugmakers.
The agency on Friday cleared Attruby, known scientifically as acoramidis, for people with a cardiac form of transthyretin amyloidosis, a progressive disease that leads to heart failure and death.
In testing, Attruby helped keep people alive and out of the hospital longer than those who’d received a placebo. Treatment was also associated with improvements in quality of life as well as markers of heart health.
Notably, the drug is approved to prevent hospitalization or death resulting from heart complications of transthyretin amyloidosis with cardiomyopathy. Investors had been skeptical BridgeBio would earn such a distinction from regulators, leading to doubts about Attruby’s commercial prospects.
BridgeBio priced Attruby at just under $19,000 for a 28-day supply, translating to an annual list cost of about $244,000.
The approval represents another step forward in treatment of transthyretin amyloidosis, which has become a top target of drugmakers over the last decade. The condition is caused by the toxic buildup of a misfolded protein, transthyretin or TTR, that the body typically uses to transport vitamin A. It primarily affects the nerves, the heart or both, and worsens with time.
Since 2018, multiple treatment options have emerged for patients with nerve damage, or polyneuropathy, a rarer form affecting an estimated 30,000 to 50,000 people in the U.S. and Europe. Progress has been slower for those with cardiac symptoms. Until recently, this form was often mistaken for other heart problems and only properly diagnosed by the time patients already had advanced heart failure. But the 2019 approval of the first treatment — a Pfizer pill called tafamidis — and adoption of less invasive diagnostic techniques have accelerated progress.
Since then, awareness of ATTR amyloidosis with cardiomyopathy has grown, driving sales of tafamidis and boosting estimates of disease prevalence. Worldwide tafamidis sales last year reached $3.3 billion and may surpass that total in 2024, making it one of Pfizer’s fastest-growing products.
In an interview, Neil Kumar, BridgeBio’s CEO, noted how those sales were achieved even as only about 50,000 people in the U.S. have been diagnosed. While an increase from a few years ago, that figure still only represents a fraction of the 250,000 to 300,000 in the country thought to have the condition. Research firm Global Market Insights estimated earlier this year that the overall market for transythretin amyloidosis treatments will surpass $11 billion by 2032, with the cardiomyopathy form accounting for the bulk of drug sales.
BridgeBio’s drug is designed to “stabilize” the misfolded TTR protein, as tafamidis does, but more completely. Vutrisirian, a competing drug from Alnylam Pharmaceuticals that could get to market next year, interferes with TTR production by silencing expression of the related gene. Others from Ionis Pharmaceuticals and Intellia Pharmaceuticals could follow.
The rush of programs has positioned ATTR amyloidosis cardiomyopathy as one of drug industry’s next commercial battlegrounds. Such a development will also mean physicians could soon have tough choices to make. While Bridgebio and Alnylam have revealed data in recent months pointing to the possible advantages of their drugs, their medicines weren’t tested directly against tafamidis or each other, meaning doctors will have to figure out which treatment is best for each patient.
“It’s going to be hard for us clinicians,” said Mazen Hanna, a cardiologist at the Cleveland Clinic, in an interview earlier this year. “The experts in the amyloidosis community are going to be left with tough decisions to make, without clear data to support our decisionmaking.”
At least so far, Wall Street has bet against BridgeBio. The company’s share price has lost most of its gains since Attruby succeeded in Phase 3 testing in July 2023, while rival Alnylam has added billions in market value after triumphing in its own late-stage trial. Investor expectations are “far lower” for BridgeBio’s drug than tafamidis or vutrisiran, wrote Cantor Fitzgerald analyst Josh Schimmer, earlier this month.
Kumar, the company’s CEO, said the company’s valuation implies Attruby will end up with a market share that would equate to “the worst second-mover launch of all time.”
“Honestly I’m perplexed by it,” he said, “and I think everyone on my board is perplexed.”
One reason for investors’ dim view is that BridgeBio has to compete against one similar, entrenched therapy and, likely within a year, another distinct alternative. Another is the company doesn’t have a track record launching medicines, having only recently transitioned to a commercial-stage enterprise. Pfizer, by comparison, has a massive salesforce and Alnylam, one of biotech’s most valuable companies, has been selling medicines for neuropathy tied to transthyretin amyloidosis for several years.
Yet Kumar think the negativity is misplaced. Some 20% to 40% of people either don’t respond to tafamidis or end up progressing after treatment, he says, making Attruby the “obvious” choice for them. While acknowledging the caveats in comparing drugs across trials, he also noted how testing showed a benefit on survival and hospitalization that appeared to materialize more quickly — as early as three months — and have a greater effect size than tafamidis.
BridgeBio expects to compete with Pfizer for newly diagnosed patients, and ultimately claim a market share of about 30%, he says. The company plans to run a head-to-head trial against tafamidis in the future as well.
“There’s probably a degree of skepticism around ‘can a bunch of science nerds launch a drug’? I get that, and I’m going to show that we can do that,” he said.
“Fundamentally, I think people will say, for a certain fraction of patients, I want to use a more potent drug that seems to have action earlier than we’ve seen before, and seems to have a greater magnitude of action.”
Bayer holds rights in Europe to Attruby through a collaboration the companies signed in March. The drug could be approved there in 2025.
