Cambridge, MA-based Molecular Insight Pharmaceuticals is gearing up for a pivotal clinical trial of a new type of diagnostic tool for spotting early signs of blockages in the heart that can lead to a heart attack or stroke.
Molecular Insight (NASDAQ: MIPI) is making this strategic move after reviewing detailed results from a 510-patient mid-stage study of its experimental imaging agent, which the company hopes to market under the name Zemiva. (I wrote about preliminary results from the study back in December.) Used in conjunction with standard cardiac tests, the imaging agent was able to help doctors accurately detect heart blockages 85 percent of the time, compared with 52 percent for standard testing alone—a difference that was highly statistically significant. The experimental diagnostic was also able to correctly identify patients who were not at risk of a cardiac event about 90 percent of the time, compared with 72 percent on the standard diagnostics.
The findings didn’t make the cut for a coveted late-breaking presentation at this weekend’s American College of Cardiology annual meeting in Orlando, FL, so the company is issuing a press release instead to get the news out to investors who will be gathering there in a few days. The company hopes to publish the findings soon in the Journal of Nuclear Cardiology, says CEO John Babich.
“This is showing unequivocal clinical benefit,” Babich says.
If Molecular Insight can prove that in the final stage of clinical trials, it could represent a big change in early diagnosis of heart attack. Something like 3.5 million Americans turn up in the emergency room every year with chest pain, forcing doctors to figure out quickly whether the patient is in danger of a heart attack. Conventional diagnosis, which relies on stress tests, can take several hours, but diagnostic imaging using Molecular Insight’s agent can be done just 10 minutes after injection.
This imaging agent, which is used in combination with a nuclear medicine camera like those used for bone scans, is also able to spot heart damage that occurred in the past 30 hours. “You can manage the patient appropriately even if they show up many hours after symptoms have resolved. And that is the big difference: there is no other imaging agent that can do that,” said James Udelson, chief of the division of cardiology at Tufts Medical Center, and the study’s principal investigator, in a company statement.
Still, like a lot of big clinical trials, this one didn’t go completely according to the plan. About one-third of all the patients in the study, 165 people, were excluded from the final analysis because hospitals either didn’t properly follow the study protocol, or didn’t capture all the necessary data. This can partly be explained by a strict protocol that didn’t allow doctors to ask for a second image to be taken to clarify an issue raised in an initial snapshot, as is often done in hospitals, Babich says. It’s also partly because emergency rooms are big, busy places where it’s sometimes difficult to stick to the rigorous criteria of a clinical trial. This trial required a lot of work—images taken with the company’s agent were read by an independent panel of three experts, and a definitive diagnosis was made by a panel of cardiologists who looked at four different measurements. Patients were followed for 30 days after they were admitted to the hospital.
So there were a lot of moving parts, and protocol violations do happen, but there were still a lot in this study. When I asked Babich if he was upset by that, he was blunt. “Of course I am,” he says.
Nonetheless, Molecular Insight has discussed this data with the FDA, and the regulators apparently told the company that it could amass enough evidence to win approval to sell the diagnostic with a single final-stage clinical trial, provided it shows “robust results.” The company is working on designing that new protocol, with an eye toward getting started in early 2010. The trial will probably enroll 700 patients at about 50 sites in the U.S. and Canada, Babich says. Molecular Insight is now looking for partners to help make that happen, he says.