SNM: Phase 1 data presented on PET heart failure imaging agent
Lantheus Medical Imaging last week at the SNM Annual Meeting in Salt Lake City announced Phase 1 data for its PET imaging agent, LMI 1195, which is in development for the evaluation of patients at risk of heart failure or sudden cardiac death.

The preliminary data showed that LMI 1195 can render high-quality, well-defined images of the cardiac autonomic nervous system, which helps regulate the electrical activity of the heart and its ability to contract, the company said. In addition to the high and uniform myocardial uptake, the radiotracer cleared quickly from the blood and had a favorable safety and dosimetry profile.

The Phase 1 data were featured in two separate poster presentations at SNM last week. Data examining the myocardial uptake of LMI 1195 were presented by Yi-Hwa Liu, PhD, associate professor of medicine (cardiology) at Yale School of Medicine in New Haven, Conn., (poster #798819), and radiation dosimetry data were presented by Joel Lazewatsky, PhD, principal research scientist for Lantheus in North Billerica, Mass., (poster #797609).

The Phase 1 study was an open-label, non-randomized, single-dose study designed to estimate the radiation dosimetry of LMI 1195 in healthy subjects undergoing a PET scan, to evaluate the safety and tolerability of the tracer, and to assess PET imaging parameters and image quality. Twelve healthy subjects received a single intravenous (IV) bolus injection of 150 to 250 megabecquerel (MBq) of LMI 1195. Dynamic PET images were obtained of the heart for 10 minutes, followed by sequential whole body images for approximately five hours.

The researchers obtained blood samples and heart rate, and monitored electrocardiogram and blood pressure prior to and during imaging. Residence times were determined from multi-exponential regression of regions of interest data normalized by injected dose. Radiation dose estimates were calculated using Organ Level INternal Dose Assessment EXponential Modeling (OLINDA/EXM). Myocardial, lung, liver and blood pool standardized uptake values were determined at different time intervals.

The data demonstrated that LMI 1195 yields a radiation dose comparable to that of other commonly-used PET radiopharmaceuticals, and that good image quality is possible at the given dose. There were no adverse events associated with LMI 1195 in this study, according to Lantheus.

The findings were augmented by preliminary results observed in six healthy subjects at a single clinical trial site that showed that LMI 1195 cleared quickly from the blood and demonstrated a favorable biodistribution for early cardiac imaging. Regional and global myocardial activity peaked within the first 10 minutes and reached a plateau at approximately 60 minutes post injection.                                            

Lantheus expects to initiate Phase 2 clinical trials later this year.