Lantheus Medical Imaging reports Phase 1 data of LMI 1195 heart failure PET imaging agent

Jun 9 2010

Lantheus Medical Imaging, Inc., a worldwide leader in diagnostic imaging, today announced Phase 1 data for its novel heart failure Positron Emission Tomography (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. In addition to the high and uniform myocardial uptake, the radiotracer cleared quickly from the blood and had a favorable safety and dosimetry profile.

“We believe that PET imaging with LMI 1195 has the potential to change how heart failure patients are evaluated”

The Phase 1 data were featured in two separate poster presentations at the SNM 57^th Annual Meeting in Salt Lake City. Data examining the myocardial uptake of LMI 1195 were presented by Yi-Hwa Liu, Ph.D., Associate Professor of Medicine (Cardiology), Yale School of Medicine on Monday, June 7 (poster #798819), and radiation dosimetry data are being presented by Joel Lazewatsky, Ph.D., Principal Research Scientist, Lantheus Medical Imaging, Inc., today, Tuesday, June 8 (poster #797609).

"There has been limited understanding to date of the functioning of the heart's autonomic nervous system through imaging," said L. Veronica Lee, M.D., Medical Director at Lantheus Medical Imaging. "The data from this Phase 1 study of LMI 1195 demonstrating safety and tolerability in healthy subjects are encouraging, as we prepare to initiate Phase 2 clinical trials later this year. Although preliminary, these data suggest that PET imaging with LMI 1195 has the potential to provide physicians with a clear view of the autonomic nervous system of the heart, which would be helpful for the identification and evaluation of heart failure patients. They also suggest that physicians may be able to view specific regions of the heart, which could potentially facilitate diagnosis and evaluation of heart failure."

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 150-250 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. Blood samples were obtained and heart rate, electrocardiogram and blood pressure were monitored prior to and during imaging. Residence times were determined from multi-exponential regression of regions of interest (ROI) data normalized by injected dose. Radiation dose estimates were calculated using Organ Level INternal Dose Assessment EXponential Modeling (OLINDA/EXM). Myocardial (M), lung, liver (LI), 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. The four highest-dose organs and their respective mean dose estimates were urinary bladder wall, 3.5-hour void (0.10 ± 0.020 mSv/MBq), kidneys (0.083 ± 0.014 mSv/MBq), thyroid (0.066 ± 0.011 mSv/MBq) and small intestine (0.046 ± 0.008 mSv/MBq). Mean effective dose was 0.026 ± 0.0012 mSv/MBq. Approximately 1.6 percent of the injected dose (ID) was seen in the myocardium initially, remaining above 1.5 percent of ID (decay-corrected) through four hours after injection. M/LI ratio was initially approximately equal increasing to more than two at four hours. Blood radioactivity cleared quickly and lung activity was low throughout the study.

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. Attenuation corrected images were reoriented into standard cardiac specific axes, and the maximal regional myocardial uptake was quantified on a sector-by-sector basis. The heart images were divided into three short axis slices and four radial sectors, and mean regional uptake for each sector was calculated. Activity was expressed as Bq/ml. There was no significant variation.

"We believe that PET imaging with LMI 1195 has the potential to change how heart failure patients are evaluated," added Dana Washburn, M.D., Vice President, Clinical Development and Medical Affairs, Lantheus Medical Imaging, Inc. "Lantheus is committed to advancing our PET imaging pipeline because of the power of PET technology to further improve cardiac imaging."

SOURCE Lantheus Medical Imaging, Inc.