FDA Approves Bridge Bio’s ATTR-CM Drug Attruby

Rare Daily Staff

The U.S. Food and Drug Administration approved BridgeBio Pharma’s Attruby for adults with ATTR-CM to reduce cardiovascular death and cardiovascular-related hospitalization.

Transthyretin amyloidosis (ATTR) is an underdiagnosed and life-threatening disease with limited treatment options that can devastate the heart and nervous system. When the transthyretin (TTR) becomes unstable due to inherited variants or aging, it can accumulate as amyloid fibrils in various organs in the body, causing ATTR. TTR amyloid deposits predominantly in the heart and/or peripheral nerves cause cardiomyopathy (ATTR-CM) and/or polyneuropathy (ATTR-PN). ATTR often dramatically impairs the quality of life, functional independence, and life expectancy of patients, as well as impacting caregivers due to the progressive nature of the disease. If left untreated, life expectancy from diagnosis is approximately four years.

Attruby is an orally administered small molecule designed to potently stabilize tetrameric transthyretin, or TTR, thereby halting at its outset the series of molecular events that give rise to TTR amyloidosis, or ATTR. Attruby is the first and only approved product with a label specifying near-complete stabilization of TTR. Attruby was designed to mimic a naturally occurring “rescue mutation” of the TTR gene (T119M) that targets the root cause of ATTR-CM, destabilization of the native TTR tetramer. Through near-complete TTR stabilization, Attruby has been shown to preserve the native function of TTR as a transport protein of thyroxine and vitamin A and to demonstrate benefit on cardiovascular outcomes.

The FDA approval is based on positive results seen in the ATTRibute-CM phase 3 study, where Attruby significantly reduced death, cardiovascular-related hospitalization, and improved quality of life.

Attruby demonstrated the most rapid benefit seen in any phase 3 study of ATTR-CM to date. In as few as three months, the time to first event (all-cause mortality or cardiovascular-related hospitalizations) durably separated relative to placebo. It showed a 42 percent reduction in composite all-cause mortality and recurrent cardiovascular-related hospitalizations events relative to placebo at month 30. It also showed a 50 percent reduction in the cumulative frequency of cardiovascular-related hospitalizations events relative to placebo at month 30

Attruby was generally well-tolerated. The most common side effects were mild and included diarrhea and abdominal pain that were resolved without drug discontinuation.

Neil Kumar, founder and CEO of BridgeBio, said that the company will pursue approvals globally, next in Europe, Japan, and Brazil. BridgeBio submitted a Marketing Authorization Application to the European Medicines Agency, with a decision expected in 2025. BridgeBio has granted exclusive rights to Bayer to commercialize Attruby for ATTR-CM in Europe.

“The need for more treatment options for patients living with ATTR-CM is crucial to achieving the goal of better outcomes and improved quality of life,” said Muriel Finkel, president of Amyloidosis Support Groups, a non-profit organization that supports amyloidosis patients and caregivers. “Access to this new therapy means more hope and more opportunity to improve the lives of patients with amyloidosis.”