Progress of ¹⁸F-flurpiridaz in Clinical Trials

18F-flurpiridaz is a novel positron emission computed tomography (PET) tracer in ongoing clinical trials in United States and Japan. A phase III prospective, open-label, multi-center study to assess the feasibility of 18F-flurpiridaz was reported by Maddahi et al. in patients with known or suspected coronary artery disease (CAD) in 2020 in United States (1). 18F-flurpiridaz binds to mitochondrial complex 1 and would distribute to the myocardium with its higher extraction fraction than those in single-photon emission computed tomography (SPECT) tracers (2). In that phase III trial, 795 participants with known or suspected CAD showed that sensitivity of 18F-flurpiridaz PET (for detection of ≥50% stenosis by invasive coronary angiography) was 71.9%, significantly (p < 0.001) higher than 99mTc labeled SPECT agent (53.7%), while specificity did not meet the prespecified noninferiority criterion (76.2% vs. 86.6%, p=NS) (1). Therefore, a second phase III Food and Drug Administration trial was planned and completed by GE Healthcare. Late phase II open-label multicenter study of PET scan using 18F-flurpiridaz (named NMB58 in Japan) to assess myocardial blood flow and diagnostic feasibility in patients with known or suspected CAD started in Japan of 2023.