As BridgeBio approaches its FDA target date for approval of TTR stabilizer acoramidis to treat the rare heart disease transthyretin amyloid cardiomyopathy (ATTR-CM), the company has presented more data indicating that it can become a force in the indication, challenging Pfizer’s dominant Vyndaqel franchise and competing with Alnylam’s TTR gene silencer Amvuttra.
An open-label extension study of the phase 3 ATTRibute-CM trial shows that acoramidis produced reductions of 36% and 34% in all-cause mortality (ACM) by Month 36 and Month 42, respectively, versus placebo.
In the composite endpoint of ACM and recurrent cardiovascular-related hospitalizations (CVH), acoramidis demonstrated reductions of 46% and 48%, respectively, at months 36 and 42.
The data look "really good,” according to Mizuho Securities analyst Salim Syed, who pointed to the 46% ACM/CVH composite figure for acoramidis at Month 36 compared to a 33% mark at the same interval for Alnylam’s Amvuttra. While cross-trial comparisons carry inherent issues such as differences in trial populations and methodologies, they're often used by analysts and others to weigh medicines against one another in the absence of head-to-head studies.
In the acoramidis study, BridgeBio pointed to the continued curve separation of the composite endpoint of ACM and recurrent CVH versus placebo.
Additionally, in the release, Bridge Bio’s chief medical officer Jonathan Fox, M.D., pointed out that acoramidis has achieved the “earliest time to separation of any known ATTR-CM treatment on clinical outcomes at three months.” He added that this supports acoramidis as a “meaningful first line option.”
“The prescribing community is eager to have another important treatment option given the remaining high unmet need for ATTR-CM patients,” added Daniel Judge, M.D., professor of medicine and cardiology at the Medical University of South Carolina.
BridgeBio presented the results Monday at the American Heart Association (AHA) Scientific Sessions in Chicago.
In August, Alnylam reported results from a trial of Amvuttra that Chief Medical Officer Pushkal Garg, M.D., called a “grand slam” and suggested that the TTR gene silencer could potentially become a standard-of-care treatment for ATTR-CM.
Over the weekend at the AHA sessions, Intellia chipped in, revealing promising results from a phase 1 trial of its in vivo therapy nexiguran ziclumeran, which uses CRISPR editing to inactivate the TTR gene.
The FDA's approval decision for acoramidis is expected by Nov. 29. A decision from European regulators isn’t expected until 2025.