Interim results from Capricor's ALLSTAR trial were anything but

Dive Brief:

  • Capricor Therapeutics' lead candidate doesn't look like it's going to win out in the mid-stage portion of a study evaluating it as a treatment for heart attack survivors, according to topline results from interim analysis released Friday.
  • ALLSTAR, a Phase 1/2 trial, was designed to show whether Capricor's drug, dubbed CAP-1002, could significantly reduce heart scarring for adults who had undergone a large heart attack and have residual cardiac dysfunction compared to placebo. Data from a six-month follow-up indicate the drug has a small chance of hitting that primary endpoint.
  • The results came as a surprise to company, particularly with regard to the placebo arm. Capricor CEO Linda Marban said on a May 12 call that some patients in the control group demonstrated 15% scar reduction or greater, "which not only was the target reduction in cardiac scar of the primary endpoint, but more importantly, simply does not agree with what has been observed in the natural history data in patients with ischemic heart disease over many many years."

Dive Insight:

Capricor said it will need more time to evaluate the interim results to see where the trial may have gone awry, but did point to several potential sources during the investor call, including the special magnetic resonance imaging (MRI) used to measure patients' heart scars.

"One possible explanation for the confounding data," Marban said, "is that the technical aspects of late gadolinium enhancement, or LGE MRI, make it less well-suited for larger studies where scanning conditions cannot be as carefully controlled and image analyses cannot be as carefully curated as in smaller trials."

To that end, Marban said her company is assessing whether LGE MRI is actually the best method to use when gathering images. The same process was used, however, in the Phase 1 portion of ALLSTAR as well as the early-stage CADUCEUS trial, which also tested CAP-1002​ in patients with recent heart failure and ventricle dysfunction.

Despite these newest results, the clinical-stage biotech isn't done with its lead candidate. There are also programs investigating CAP-1002 as a treatment for advanced heart failure and cardiomyopathy in patients with Duchenne muscular dystrophy (DMD), and Capricor is doubling down on the latter indication.

It is planning to start a new placebo-controlled trial for CAP-1002 in DMD during the latter half of this year. While details still need to be ironed out, Marban said the study is poised to enroll less than 100 patients at this point, though that could change once it meets with the Food and Drug Administration.

Less clear is where CAP-1002 goes in myocardial regeneration. Johnson & Johnson's Janssen picked up the option for exclusive worldwide rights to the drug in 2013. Capricor said it has shared the ALLSTAR interim results with the big pharma, which has 60 days following the interim data to exercise that option, but did not provide many other details about their relationship during the investor call.

"We are fully speed ahead with our Duchenne program; we are meeting with the FDA ... we're designing the next trial, and we're planning on proceeding with or without Janssen in the picture," Marban said.

Capricor's shares fell nearly 60% to $1.23 apiece in Friday morning trading.

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Filed Under: Clinical Trials
Top image credit: Dollar Photo Club