Investigators reported that the novel perflutren-based ultrasound-enhancing agent MVT-100 showed improved left ventricular opacification and reduced acoustic shadowing compared with Definity in an early-phase study of healthy volunteers.
The findings were reported in a late-breaking abstract at the American Society of Echocardiography (ASE) 2026 Scientific Sessions. Evan Unger, MD, who is affiliated with Microvascular Therapeutics, the developer of MVT-100, discussed the findings in an interview with Conexiant.
According to the abstract, MVT-100 is being developed as an ultrasound-enhancing agent designed to improve echocardiographic image quality while reducing acoustic shadowing and allowing room-temperature storage. Presentation materials also listed potential operational considerations, including room-temperature storage and longer duration of use after activation.
Asked about the practical implications if the findings hold up in larger studies, Dr. Unger said room-temperature storage could make the agent easier to use in some settings.
“Being room temperature storage is going to be easier, make it cheaper, and allow for use potentially in places like outpatient clinics that don’t want to store refrigerated products,” Dr. Unger said. He added that longer contrast duration could provide more time for imaging and potentially reduce the need for repeat injections in some cases.
Study Details
In this prospective interventional phase 1/2 study, healthy volunteers underwent echocardiography and received ascending dilute bolus doses of MVT-100 or Definity at 1.0, 1.5, 2.0, and 2.5 mL. Each dilute bolus was prepared using 1.3 mL of activated product and 8.7 mL of normal saline.
Participants were monitored prior to and following contrast administration using vital sign assessments, electrocardiograms, and laboratory testing. Three expert echocardiographers, blinded to the administered agent, independently evaluated images obtained at each dose level during baseline and post-dose imaging intervals of 0 to 1.5, 1.5 to 3.0, and 3.0 to 4.5 minutes.
Study assessments included left ventricular cavity opacification, segmental endocardial border delineation based on the 17-segment ASE model, and the presence of excessive acoustic shadowing.
Key Findings
No serious adverse events were reported with either MVT-100 or Definity. Investigators also reported no clinically significant changes in vital signs, electrocardiographic findings, hematology, serum chemistry, or immunologic parameters after either agent. In the presentation materials, investigators noted no clinically meaningful adverse laboratory trends across hematologic, metabolic, hepatic, renal, coagulation, or inflammatory markers. Differences in inorganic phosphorus, albumin, and bilirubin were observed between groups, but investigators stated these differences were present at both baseline and discharge and that all values remained within normal reference ranges. No flank pain was reported in either arm.
On a 0-to-3 opacification scale, investigators reported that MVT-100 showed a statistically significant aggregate shift toward higher left ventricular opacification scores compared with Definity microspheres. In the data table, MVT-100 scores were numerically higher than Definity at most dose levels and post-dose imaging intervals, although not at every individual time point.
Overall shadowing rates were approximately 3% with MVT-100 compared with 8% with Definity, “representing a significant reduction in attenuation and improved visualization of myocardial segments,” the researchers wrote. Segment-level analyses likewise showed statistically significant reductions in acoustic shadowing across most left ventricular segments.
According to the researchers, representative echocardiographic images demonstrated improved cavity opacification with less attenuation following administration of MVT-100 compared with Definity.
Pivotal Trial Plans
Asked what pivotal studies need to show, Dr. Unger said the next trial is expected to compare baseline noncontrast imaging with postcontrast imaging in participants with at least two nonvisualizable endocardial border segments, rather than directly comparing MVT-100 with Definity. He said the study would need to demonstrate significant improvement in visualization of the left ventricular border.
“The label claims initially would be the same as Definity,” Dr. Unger said, adding that he hoped the claims could later be broadened.
Dr. Unger said MVT-100 could potentially reach the market as early as 2028 if development proceeds successfully.
The researchers concluded that MVT-100 demonstrated superior left ventricular opacification and significantly reduced acoustic shadowing compared with Definity while maintaining a favorable safety profile. They wrote that the findings support further pivotal development of MVT-100 as a next-generation ultrasound-enhancing agent for echocardiography.
The presentation materials listed NHLBI SBIR/CRP support related to development, commercialization, manufacturing, and characterization of MVT-100. The slides also identified Microvascular Therapeutics-affiliated contributors.
Sources: Journal of the American Society of Echocardiography abstract; ASE 2026 presentation materials; Conexiant interview with Evan Unger, MD.