Well that's the thing. Because it was a blinded trial, they have no idea who got leronlimab and who got placebo, but 2 people had cardiac events, so in CYDY's words "We suspended the trial out of an abundance of caution" until they get the information needed. They hope to have it up and running again in April.
The FDA had no choice at that point but to suspend the US trials until it all gets sorted out.