Is it possible to make an asynchronous call in JXA Objective-C bridge

Question

I'm trying to use Objective-C Bridge in a Javascript for Automation script to access the Event Store. Here's my code:

ObjC.import('EventKit');

var store = $.EKEventStore.alloc.initWithAccessToEntityTypes($.EKEntityMaskReminder);
var predicate = store.predicateForRemindersInCalendars($.Nil);

store.fetchRemindersMatchingPredicateCompletion(predicate, function(reminders){
console.log(reminders)
});

However the script completes, presumably before the function is called- nothing appears in the log.

Is there a way to make this work, such as to make it run synchronously instead, or to make the script wait until the completion handler finishes?