Acoramidis

The much-ballyhooed competition between BridgeBio and Alnylam has been less of a tug-of-war and more of a rising-tide-lifts-all-boats scenario. That’s because both companies are hitting the milestones they each laid out for the respective launches of their transthyretin-mediated amyloid cardiomyopathy (ATTR-CM) treatments, and that’s likely to continue, even as other companies attempt to enter the market, analysts tell Endpoints News . For BridgeBio, the commercial success of Attruby — combined with two late-stage rare disease wins this week — underscore the company’s increasingly diverse portfolio. Alnylam, meanwhile, is headed toward its long-stated goal of becoming profitable by the end of this year. “We’re definitely, I’d say, poised to achieve this goal that we set out for ourselves back in 2021,” Alnylam CEO Yvonne Greenstreet told Endpoints News . Attruby and Alnylam’s Amvuttra, which both received approval for ATTR-CM within the last year, continue to record strong sales and quarter-over-quarter growth. Amvuttra generated $685 million in sales in the third quarter, up from $492 million in the second quarter, and Attruby pulled in $108.1 million compared to $71.5 million in Q2. But the raw sales numbers don’t tell the whole story. Amvuttra costs more than twice as much as Attruby. Amvuttra is also covered by Medicare Part B, while Attruby is covered by Part D. Part B drugs are typically more expensive because they’re administered in doctors’ offices, and clinicians have a different set of incentives to prescribe them. Attruby is also a small molecule drug, which is typically cheaper to manufacture than other drugs. (Amvuttra is an RNA silencer.) What’s really driving the growth for both drugs is a significant increase in the number of patients being diagnosed, according to TD Cowen analyst Ritu Baral. Some investors theorized that ATTR-CM was underdiagnosed. Even after the first ATTR-CM drug was approved in 2019 — Pfizer’s Vyndamax/Vyndaqel franchise — it was primarily prescribed to patients with severe symptoms. That created an opening for both drugs to record strong early sales despite near-simultaneous launches, Baral said. But investor skepticism also drove the idea there would be stiff competition, she added. The market potential “just wasn’t recognized by the investors, where it was by the doctors,” Baral said. Most analysts say the key metric to watch is related to underdiagnoses. The goal is to grow the number of “first-line” individuals on a drug rather than simply count the patients who switch from Vyndamax/Vyndaqel. That’s happening, according to William Blair analyst Myles Minter, because there are so many undiagnosed patients. “The moment that I start hearing all these companies going, ‘Hey, the majority of our patients are switches,’ then I’ll start to get worried,” he said. “Because then you’re just fighting for a smaller piece of the pie.” In a third-quarter earnings call, BridgeBio CEO Neil Kumar said his “best guess” of Attruby’s first-line market share is “well in the 20s” in terms of percentage of market share. Kumar said he couldn’t give a precise figure, because Alnylam and Pfizer hadn’t yet reported their earnings. (Pfizer is set to report on Tuesday.) Alnylam did not break down the first-line and “switch” figures in Thursday’s earnings call, but Greenstreet told Endpoints that Amvuttra is “highly competitive” in that “first-line” segment. Despite the strong sales figures for each drug, BridgeBio and Alnylam’s stock prices both dropped on Thursday after Alnylam reported its quarterly results. BridgeBio $BBIO shares closed down 4.9%, while Alnylam $ALNY fell about 6.7%. It’s unclear why this happened. More than a handful of analysts, including Cantor Fitzgerald’s Olivia Brayer, put out notes to investors saying investor expectations have become inflated, particularly for Alnylam. Some are “starting to question” how much upside is left in Alnylam’s stock, given the company likely won’t launch another drug for several years, Brayer wrote. Leerink analyst Mani Foroohar agreed, saying investors seemed to want accelerating sales growth rather than the stable, linear growth Alnylam has shown so far. “As investor expectations got really, really high, driven by technical as well as fundamental reasons, it became tougher and tougher to hit that bar,” he told Endpoints. BridgeBio is more insulated from this dynamic, he added, because the company is closer to launching other drugs. The rare disease wins this week point to at least two new drugs coming to market sometime in 2027. Baral noted that the stock drops may have been influenced by other incentives. Attruby and Amvuttra sales are intensely scrutinized every quarter when doing so may not be warranted, given the “explosive” market that’s unfolded in the last 12 months. “Everybody’s pushing their narrative, and Alnylam has frequently been a stock that has been controversial,” Baral said. “Let’s put it that way.”