BridgeBio stock jumps after rival heart drug fails key trial

A rival drug failure can sometimes move a biotech stock almost as much as a company’s own clinical data.

That is what happened to BridgeBio on July 9.

BridgeBio (BBIO) shares jumped after AstraZeneca and Ionis said Wainua failed to meet the main goal in a late-stage trial for transthyretin-mediated amyloid cardiomyopathy, or ATTR-CM, a heart disease caused by protein buildup that can make it harder for the heart to pump blood.

BridgeBio stock was recently trading at $89.86, up 14.7% from the previous close. The stock opened at $84 and traded as high as $93.31 during July 9’s session.

The rally added roughly $2.2 billion to BridgeBio’s market value based on its intraday market capitalization. The move shows investors were not just reacting to a failed trial. They were reassessing the competitive field around a drug BridgeBio already sells.

AstraZeneca trial miss changes the heart-drug race

Wainua, also known as eplontersen, was being tested in the Phase 3 CARDIO-TTRansform trial. AstraZeneca said the drug did not meet the primary efficacy endpoint of reducing cardiovascular mortality and recurrent cardiovascular events compared with placebo.

The trial enrolled 1,432 patients across 130 study sites in 20 countries. AstraZeneca said ATTR-CM affects an estimated 300,000 to 500,000 people worldwide.

The result had a direct read-through for the ATTR-CM market because Wainua was tested on top of standard care, including stabilizer therapy. AstraZeneca said that approach did not provide a statistically significant benefit on the trial’s main measure. In patients on stabilizer therapy at baseline, no treatment effect was observed.

Reuters reported that the setback dimmed prospects for a drug that analysts had predicted could reach about $2 billion in peak sales. The update sent AstraZeneca and Ionis shares lower and lifted U.S. competitors with approved ATTR-CM drugs, including BridgeBio and Alnylam.

Key numbers behind the BridgeBio move

• 14.7%: BridgeBio’s recent intraday gain
• About $2.2 billion: estimated market value added by the stock move
• 1,432: patients in the CARDIO-TTRansform trial
• 300,000 to 500,000: estimated global ATTR-CM patient population
• $2 billion: potential Wainua peak sales opportunity cited by Reuters
• $180.6 million: BridgeBio’s first-quarter U.S. Attruby net product revenue

Related: Eidos Shares Jump on Plan to Be Bought by BridgeBio

Why BridgeBio investors are watching Wainua

The Wainua result may change how investors view the market around a product that BridgeBio already has.

BridgeBio’s Attruby, also known as acoramidis, is approved for ATTR-CM. The company reported $194.5 million in first-quarter total revenue, including $180.6 million in U.S. Attruby net product revenue.

With Attruby already generating revenue, investors are watching whether a less crowded competitive field could help BridgeBio grow prescriptions, reimbursement access, and market share.

Alnylam also benefited from the Wainua setback. Its Amvuttra, or vutrisiran, won FDA approval in 2025 for ATTR-CM in adults to reduce cardiovascular mortality, cardiovascular hospitalizations and urgent heart failure visits.

The read-through was more direct for Alnylam because Amvuttra and Wainua both lower TTR. BridgeBio’s Attruby is a stabilizer, but a setback for a potential ATTR-CM competitor still affects how investors view the market.

Related: Biotech stock sends Wall Street surprising signal

BridgeBio still has to prove the opening

The ATTR-CM market still includes other approved treatments, including Pfizer’s Vyndaqel and Alnylam’s Amvuttra. AstraZeneca and Ionis also said they will analyze the full Wainua data set and share the results with the scientific community at the European Society of Cardiology Congress in August.

For BridgeBio’s investors, the next question is whether Attruby can keep gaining prescriptions, secure payer access and turn a more favorable competitive setup into stronger sales growth.

Martin Philip &sol Getty Images

The AstraZeneca-Ionis trial miss gives BridgeBio a cleaner competitive setup in ATTR-CM. The next test is whether Attruby can turn that opening into stronger prescriptions, reimbursement access, and sales.

Related: AstraZeneca says AI is raising its odds where most drugs fail